Article

Federal Health Care Data Trends (click to view the digital edition) is a special supplement to Federal Practitioner highlighting the latest research and study outcomes related to the health of veteran and active-duty populations. 

In this issue:

• Vaccinations
• Mental Health and Related Disorders
• LGBTQ+ Veterans
• Military Sexual Trauma
• Sleep Disorders
• Respiratory Illnesses
• HIV Care in the VA
• Rheumatologic Diseases
• The Cancer-Obesity Connection
• Skin Health for Active-Duty Personnel
• Contraception
• Chronic Kidney Disease
• Cardiovascular Diseases
• Neurologic Disorders
• Hearing, Vision, and Balance

Federal Practitioner would like to thank the following experts for their review of content and helpful guidance in developing this issue: 

Kelvin N.V. Bush, MD, FACC, CCDS; Sonya Borrero, MD, MS; Kenneth L. Cameron, PhD, MPH, ATC, FNATA; Jason DeViva, PhD; Ellen Lockard Edens, MD; Leonard E. Egede, MD, MS; Amy Justice, MD, PhD; Stephanie Knudson, MD; Willis H. Lyford, MD; Sarah O. Meadows, PhD; Tamara Schult, PhD, MPH; Eric L. Singman, MD, PhD; Art Wallace, MD, PhD; Elizabeth Waterhouse, MD, FAAN

Federal Health Care Data Trends (click to view the digital edition) is a special supplement to Federal Practitioner highlighting the latest research and study outcomes related to the health of veteran and active-duty populations. 

In this issue:

• Vaccinations
• Mental Health and Related Disorders
• LGBTQ+ Veterans
• Military Sexual Trauma
• Sleep Disorders
• Respiratory Illnesses
• HIV Care in the VA
• Rheumatologic Diseases
• The Cancer-Obesity Connection
• Skin Health for Active-Duty Personnel
• Contraception
• Chronic Kidney Disease
• Cardiovascular Diseases
• Neurologic Disorders
• Hearing, Vision, and Balance

Federal Practitioner would like to thank the following experts for their review of content and helpful guidance in developing this issue: 

Kelvin N.V. Bush, MD, FACC, CCDS; Sonya Borrero, MD, MS; Kenneth L. Cameron, PhD, MPH, ATC, FNATA; Jason DeViva, PhD; Ellen Lockard Edens, MD; Leonard E. Egede, MD, MS; Amy Justice, MD, PhD; Stephanie Knudson, MD; Willis H. Lyford, MD; Sarah O. Meadows, PhD; Tamara Schult, PhD, MPH; Eric L. Singman, MD, PhD; Art Wallace, MD, PhD; Elizabeth Waterhouse, MD, FAAN

Federal Health Care Data Trends (click to view the digital edition) is a special supplement to Federal Practitioner highlighting the latest research and study outcomes related to the health of veteran and active-duty populations. 

In this issue:

• Vaccinations
• Mental Health and Related Disorders
• LGBTQ+ Veterans
• Military Sexual Trauma
• Sleep Disorders
• Respiratory Illnesses
• HIV Care in the VA
• Rheumatologic Diseases
• The Cancer-Obesity Connection
• Skin Health for Active-Duty Personnel
• Contraception
• Chronic Kidney Disease
• Cardiovascular Diseases
• Neurologic Disorders
• Hearing, Vision, and Balance

Federal Practitioner would like to thank the following experts for their review of content and helpful guidance in developing this issue: 

Kelvin N.V. Bush, MD, FACC, CCDS; Sonya Borrero, MD, MS; Kenneth L. Cameron, PhD, MPH, ATC, FNATA; Jason DeViva, PhD; Ellen Lockard Edens, MD; Leonard E. Egede, MD, MS; Amy Justice, MD, PhD; Stephanie Knudson, MD; Willis H. Lyford, MD; Sarah O. Meadows, PhD; Tamara Schult, PhD, MPH; Eric L. Singman, MD, PhD; Art Wallace, MD, PhD; Elizabeth Waterhouse, MD, FAAN

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Although moderately hypofractionated radiotherapy (MHRT) is an accepted treatment for localized prostate cancer, its adaptation remains limited in the United States.^1,2 MHRT theoretically exploits α/β ratio differences between the prostate (1.5 Gy), bladder (5-10 Gy), and rectum (3 Gy), thereby reducing late treatment-related adverse effects compared with those of conventional fractionation at biologically equivalent doses.^3-8 Multiple randomized noninferiority trials have demonstrated equivalent outcomes between MHRT and conventional fraction with no appreciable increase in patient-reported toxicity.^9-14 Although these studies have led to the acceptance of MHRT as a standard treatment, the majority of these trials involve individuals with low- and intermediate-risk disease.

There are less phase 3 data addressing MHRT for high-risk prostate cancer (HRPC).^10,12,14-17 Only 2 studies examined predominately high-risk populations, accounting for 83 and 292 patients, respectively.^15,16 Additional phase 3 trials with small proportions of high-risk patients (n = 126, 12%; n = 53, 35%) offer limited additional information regarding clinical outcomes and toxicity rates specific to high-risk disease.^10-12 Numerous phase 1 and 2 studies report various field designs and fractionation plans for MHRT in the context of high-risk disease, although the applicability of these data to off-trial populations remains limited.^18-20

Furthermore, African American individuals are underrepresented in the trials establishing the role of MHRT despite higher rates of prostate cancer incidence, more advanced disease stage at diagnosis, and higher rates of prostate cancer–specific survival (PCSS) when compared with White patients.²¹ Racial disparities across patients with prostate cancer and their management are multifactorial across health care literacy, education level, access to care (including transportation issues), and issues of adherence and distrust.^22-25 Correlation of patient race to prostate cancer outcomes varies greatly across health care systems, with the US Department of Veterans Affairs (VA) equal access system providing robust mental health services and transportation services for some patients, while demonstrating similar rates of stage-adjusted PCSS between African American and White patients across a broad range of treatment modalities.^26-28 Given the paucity of data exploring outcomes following MHRT for African American patients with HRPC, the present analysis provides long-term clinical outcomes and toxicity profiles for an off-trial majority African American population with HRPC treated with MHRT within the VA.

Methods

Records were retrospectively reviewed under an institutional review board–approved protocol for all patients with HRPC treated with definitive MHRT at the Durham Veterans Affairs Healthcare System in North Carolina between November 2008 and August 2018. Exclusion criteria included < 12 months of follow-up or elective nodal irradiation. Demographic variables obtained included age at diagnosis, race, clinical T stage, pre-MHRT prostate-specific antigen (PSA), Gleason grade group at diagnosis, favorable vs unfavorable high-risk disease, pre-MHRT international prostate symptom score (IPSS), and pre-MHRT urinary medication usage (yes/no).²⁹

Concurrent androgen deprivation therapy (ADT) was initiated 6 to 8 weeks before MHRT unless medically contraindicated per the discretion of the treating radiation oncologist. Patients generally received 18 to 24 months of ADT, with those with favorable HRPC (ie, T1c disease with either Gleason 4+4 and PSA < 10 mg/mL or Gleason 3+3 and PSA > 20 ng/mL) receiving 6 months after 2015.²⁹ Patients were simulated supine in either standard or custom immobilization with a full bladder and empty rectum. MHRT fractionation plans included 70 Gy at 2.5 Gy per fraction and 60 Gy at 3 Gy per fraction. Radiotherapy targets included the prostate and seminal vesicles without elective nodal coverage per institutional practice. Treatments were delivered following image guidance, either prostate matching with cone beam computed tomography or fiducial matching with kilo voltage imaging. All patients received intensity-modulated radiotherapy. For plans delivering 70 Gy at 2.5 Gy per fraction, constraints included bladder V (volume receiving) 70 < 10 cc, V65 ≤ 15%, V40 ≤ 35%, rectum V70 < 10 cc, V65 ≤ 10%, V40 ≤ 35%, femoral heads maximum point dose ≤ 40 Gy, penile bulb mean dose ≤ 50 Gy, and small bowel V40 ≤ 1%. For plans delivering 60 Gy at 3 Gy per fraction, constraints included rectum V57 ≤ 15%, V46 ≤ 30%, V37 ≤ 50%, bladder V60 ≤ 5%, V46 ≤ 30%, V37 ≤ 50%, and femoral heads V43 ≤ 5%.

Gastrointestinal (GI) and genitourinary (GU) toxicities were graded using Common Terminology Criteria for Adverse Events (CTCAE), version 5.0, with acute toxicity defined as on-treatment < 3 months following completion of MHRT. Late toxicity was defined as ≥ 3 months following completion of MHRT. Individuals were seen in follow-up at 6 weeks and 3 months with PSA and testosterone after MHRT completion, then every 6 to 12 months for 5 years and annually thereafter. Each follow-up visit included history, physical examination, IPSS, and CTCAE grading for GI and GU toxicity.

The Wilcoxon rank sum test and χ² test were used to compare differences in demographic data, dosimetric parameters, and frequency of toxicity events with respect to patient race. Clinical endpoints including biochemical recurrence-free survival (BRFS; defined by Phoenix criteria as 2.0 above PSA nadir), distant metastases-free survival (DMFS), PCSS, and overall survival (OS) were estimated from time of radiotherapy completion by the Kaplan-Meier method and compared between African American and White race by log-rank testing.³⁰ Late GI and GU toxicity-free survival were estimated by Kaplan-Meier plots and compared between African American and White patients by the log-rank test. Statistical analysis was performed using SAS 9.4.

Results

We identified 143 patients with HRPC treated with definitive MHRT between November 2008 and August 2018 (Table 1). Mean age was 65 years (range, 36-80 years); 57% were African American men. Eighty percent of individuals had unfavorable high-risk disease. Median (IQR) PSA was 14.4 (7.8-28.6). Twenty-six percent had grade group 1-3 disease, 47% had grade group 4 disease, and 27% had grade group 5 disease. African American patients had significantly lower pre-MHRT IPSS scores than White patients (mean IPSS, 11 vs 14, respectively; P = .02) despite similar rates of preradiotherapy urinary medication usage (66% and 66%, respectively).

Eighty-six percent received 70 Gy over 28 fractions, with institutional protocol shifting to 60 Gy over 20 fractions (14%) in June 2017. The median (IQR) duration of radiotherapy was 39 (38-42) days, with 97% of individuals undergoing ADT for a median (IQR) duration of 24 (24-36) months. The median follow-up time was 38 months, with 57 (40%) patients followed for at least 60 months.

Grade 3 GI and GU acute toxicity events were observed in 1% and 4% of all individuals, respectively (Table 2). No acute GI or GU grade 4+ events were observed. No significant differences in acute GU or GI toxicity were observed between African American and White patients.

Discussion

In this study, we reported acute and late GI and GU toxicity rates as well as clinical outcomes for a majority African American population with predominately unfavorable HRPC treated with MHRT in an equal access health care environment. We found that MHRT was well tolerated with high rates of biochemical control, PCSS, and OS. Additionally, outcomes were not significantly different across patient race. To our knowledge, this is the first report of MHRT for HRPC in a majority African American population.

We found that MHRT was an effective treatment for patients with HRPC, in particular those with unfavorable high-risk disease. While prior prospective and randomized studies have investigated the use of MHRT, our series was larger than most and had a predominately unfavorable high-risk population.^12,15-17 Our biochemical and PCSS rates compare favorably with those of HRPC trial populations, particularly given the high proportion of unfavorable high-risk disease.^12,15,16 Despite similar rates of biochemical control, OS was lower in the present cohort than in HRPC trial populations, even with a younger median age at diagnosis. The similarly high rates of non–HRPC-related death across race may reflect differences in baseline comorbidities compared with trial populations as well as reported differences between individuals in the VA and the private sector.³¹ This suggests that MHRT can be an effective treatment for patients with unfavorable HRPC.

We did not find any differences in outcomes between African American and White individuals with HRPC treated with MHRT. Furthermore, our study demonstrates long-term rates of BRFS and PCSS in a majority African American population with predominately unfavorable HRPC that are comparable with those of prior randomized MHRT studies in high-risk, predominately White populations.^12,15,16 Prior reports have found that African American men with HRPC may be at increased risk for inferior clinical outcomes due to a number of socioeconomic, biologic, and cultural mediators.^26,27,32 Such individuals may disproportionally benefit from shorter treatment courses that improve access to radiotherapy, a well-documented disparity for African American men with localized prostate cancer.^33-36 The VA is an ideal system for studying racial disparities within prostate cancer, as accessibility of mental health and transportation services, income, and insurance status are not barriers to preventative or acute care.³⁷ Our results are concordant with those previously seen for African American patients with prostate cancer seen in the VA, which similarly demonstrate equal outcomes with those of other races.^28,36 Incorporation of the earlier mentioned VA services into oncologic care across other health care systems could better characterize determinants of racial disparities in prostate cancer, including the prognostic significance of shortening treatment duration and number of patient visits via MHRT.

Limitations

This study has several inherent limitations. While the size of the current HRPC cohort is notably larger than similar populations within the majority of phase 3 MHRT trials, these data derive from a single VA hospital. It is unclear whether these outcomes would be representative in a similar high-risk population receiving care outside of the VA equal access system. Follow-up data beyond 5 years was available for less than half of patients, partially due to nonprostate cancer–related mortality at a higher rate than observed in HRPC trial populations.^12,15,16 Furthermore, all GI toxicity events were exclusively physician reported, and GU toxicity reporting was limited in the off-trial setting with not all patients routinely completing IPSS questionnaires following MHRT completion. However, all patients were treated similarly, and radiation quality was verified over the treatment period with mandated accreditation, frequent standardized output checks, and systematic treatment review.³⁹

Conclusions

Patients with HRPC treated with MHRT in an equal access, off-trial setting demonstrated favorable rates of biochemical control with acceptable rates of acute and late GI and GU toxicities. Clinical outcomes, including biochemical control, were not significantly different between African American and White patients, which may reflect equal access to care within the VA irrespective of income and insurance status. Incorporating VA services, such as access to primary care, mental health services, and transportation across other health care systems may aid in characterizing and mitigating racial and gender disparities in oncologic care.  

Acknowledgments

Portions of this work were presented at the November 2020 ASTRO conference. ⁴⁰

Although moderately hypofractionated radiotherapy (MHRT) is an accepted treatment for localized prostate cancer, its adaptation remains limited in the United States.^1,2 MHRT theoretically exploits α/β ratio differences between the prostate (1.5 Gy), bladder (5-10 Gy), and rectum (3 Gy), thereby reducing late treatment-related adverse effects compared with those of conventional fractionation at biologically equivalent doses.^3-8 Multiple randomized noninferiority trials have demonstrated equivalent outcomes between MHRT and conventional fraction with no appreciable increase in patient-reported toxicity.^9-14 Although these studies have led to the acceptance of MHRT as a standard treatment, the majority of these trials involve individuals with low- and intermediate-risk disease.

There are less phase 3 data addressing MHRT for high-risk prostate cancer (HRPC).^10,12,14-17 Only 2 studies examined predominately high-risk populations, accounting for 83 and 292 patients, respectively.^15,16 Additional phase 3 trials with small proportions of high-risk patients (n = 126, 12%; n = 53, 35%) offer limited additional information regarding clinical outcomes and toxicity rates specific to high-risk disease.^10-12 Numerous phase 1 and 2 studies report various field designs and fractionation plans for MHRT in the context of high-risk disease, although the applicability of these data to off-trial populations remains limited.^18-20

Furthermore, African American individuals are underrepresented in the trials establishing the role of MHRT despite higher rates of prostate cancer incidence, more advanced disease stage at diagnosis, and higher rates of prostate cancer–specific survival (PCSS) when compared with White patients.²¹ Racial disparities across patients with prostate cancer and their management are multifactorial across health care literacy, education level, access to care (including transportation issues), and issues of adherence and distrust.^22-25 Correlation of patient race to prostate cancer outcomes varies greatly across health care systems, with the US Department of Veterans Affairs (VA) equal access system providing robust mental health services and transportation services for some patients, while demonstrating similar rates of stage-adjusted PCSS between African American and White patients across a broad range of treatment modalities.^26-28 Given the paucity of data exploring outcomes following MHRT for African American patients with HRPC, the present analysis provides long-term clinical outcomes and toxicity profiles for an off-trial majority African American population with HRPC treated with MHRT within the VA.

Methods

Records were retrospectively reviewed under an institutional review board–approved protocol for all patients with HRPC treated with definitive MHRT at the Durham Veterans Affairs Healthcare System in North Carolina between November 2008 and August 2018. Exclusion criteria included < 12 months of follow-up or elective nodal irradiation. Demographic variables obtained included age at diagnosis, race, clinical T stage, pre-MHRT prostate-specific antigen (PSA), Gleason grade group at diagnosis, favorable vs unfavorable high-risk disease, pre-MHRT international prostate symptom score (IPSS), and pre-MHRT urinary medication usage (yes/no).²⁹

Concurrent androgen deprivation therapy (ADT) was initiated 6 to 8 weeks before MHRT unless medically contraindicated per the discretion of the treating radiation oncologist. Patients generally received 18 to 24 months of ADT, with those with favorable HRPC (ie, T1c disease with either Gleason 4+4 and PSA < 10 mg/mL or Gleason 3+3 and PSA > 20 ng/mL) receiving 6 months after 2015.²⁹ Patients were simulated supine in either standard or custom immobilization with a full bladder and empty rectum. MHRT fractionation plans included 70 Gy at 2.5 Gy per fraction and 60 Gy at 3 Gy per fraction. Radiotherapy targets included the prostate and seminal vesicles without elective nodal coverage per institutional practice. Treatments were delivered following image guidance, either prostate matching with cone beam computed tomography or fiducial matching with kilo voltage imaging. All patients received intensity-modulated radiotherapy. For plans delivering 70 Gy at 2.5 Gy per fraction, constraints included bladder V (volume receiving) 70 < 10 cc, V65 ≤ 15%, V40 ≤ 35%, rectum V70 < 10 cc, V65 ≤ 10%, V40 ≤ 35%, femoral heads maximum point dose ≤ 40 Gy, penile bulb mean dose ≤ 50 Gy, and small bowel V40 ≤ 1%. For plans delivering 60 Gy at 3 Gy per fraction, constraints included rectum V57 ≤ 15%, V46 ≤ 30%, V37 ≤ 50%, bladder V60 ≤ 5%, V46 ≤ 30%, V37 ≤ 50%, and femoral heads V43 ≤ 5%.

Gastrointestinal (GI) and genitourinary (GU) toxicities were graded using Common Terminology Criteria for Adverse Events (CTCAE), version 5.0, with acute toxicity defined as on-treatment < 3 months following completion of MHRT. Late toxicity was defined as ≥ 3 months following completion of MHRT. Individuals were seen in follow-up at 6 weeks and 3 months with PSA and testosterone after MHRT completion, then every 6 to 12 months for 5 years and annually thereafter. Each follow-up visit included history, physical examination, IPSS, and CTCAE grading for GI and GU toxicity.

The Wilcoxon rank sum test and χ² test were used to compare differences in demographic data, dosimetric parameters, and frequency of toxicity events with respect to patient race. Clinical endpoints including biochemical recurrence-free survival (BRFS; defined by Phoenix criteria as 2.0 above PSA nadir), distant metastases-free survival (DMFS), PCSS, and overall survival (OS) were estimated from time of radiotherapy completion by the Kaplan-Meier method and compared between African American and White race by log-rank testing.³⁰ Late GI and GU toxicity-free survival were estimated by Kaplan-Meier plots and compared between African American and White patients by the log-rank test. Statistical analysis was performed using SAS 9.4.

Results

We identified 143 patients with HRPC treated with definitive MHRT between November 2008 and August 2018 (Table 1). Mean age was 65 years (range, 36-80 years); 57% were African American men. Eighty percent of individuals had unfavorable high-risk disease. Median (IQR) PSA was 14.4 (7.8-28.6). Twenty-six percent had grade group 1-3 disease, 47% had grade group 4 disease, and 27% had grade group 5 disease. African American patients had significantly lower pre-MHRT IPSS scores than White patients (mean IPSS, 11 vs 14, respectively; P = .02) despite similar rates of preradiotherapy urinary medication usage (66% and 66%, respectively).

Eighty-six percent received 70 Gy over 28 fractions, with institutional protocol shifting to 60 Gy over 20 fractions (14%) in June 2017. The median (IQR) duration of radiotherapy was 39 (38-42) days, with 97% of individuals undergoing ADT for a median (IQR) duration of 24 (24-36) months. The median follow-up time was 38 months, with 57 (40%) patients followed for at least 60 months.

Grade 3 GI and GU acute toxicity events were observed in 1% and 4% of all individuals, respectively (Table 2). No acute GI or GU grade 4+ events were observed. No significant differences in acute GU or GI toxicity were observed between African American and White patients.

Discussion

In this study, we reported acute and late GI and GU toxicity rates as well as clinical outcomes for a majority African American population with predominately unfavorable HRPC treated with MHRT in an equal access health care environment. We found that MHRT was well tolerated with high rates of biochemical control, PCSS, and OS. Additionally, outcomes were not significantly different across patient race. To our knowledge, this is the first report of MHRT for HRPC in a majority African American population.

We found that MHRT was an effective treatment for patients with HRPC, in particular those with unfavorable high-risk disease. While prior prospective and randomized studies have investigated the use of MHRT, our series was larger than most and had a predominately unfavorable high-risk population.^12,15-17 Our biochemical and PCSS rates compare favorably with those of HRPC trial populations, particularly given the high proportion of unfavorable high-risk disease.^12,15,16 Despite similar rates of biochemical control, OS was lower in the present cohort than in HRPC trial populations, even with a younger median age at diagnosis. The similarly high rates of non–HRPC-related death across race may reflect differences in baseline comorbidities compared with trial populations as well as reported differences between individuals in the VA and the private sector.³¹ This suggests that MHRT can be an effective treatment for patients with unfavorable HRPC.

We did not find any differences in outcomes between African American and White individuals with HRPC treated with MHRT. Furthermore, our study demonstrates long-term rates of BRFS and PCSS in a majority African American population with predominately unfavorable HRPC that are comparable with those of prior randomized MHRT studies in high-risk, predominately White populations.^12,15,16 Prior reports have found that African American men with HRPC may be at increased risk for inferior clinical outcomes due to a number of socioeconomic, biologic, and cultural mediators.^26,27,32 Such individuals may disproportionally benefit from shorter treatment courses that improve access to radiotherapy, a well-documented disparity for African American men with localized prostate cancer.^33-36 The VA is an ideal system for studying racial disparities within prostate cancer, as accessibility of mental health and transportation services, income, and insurance status are not barriers to preventative or acute care.³⁷ Our results are concordant with those previously seen for African American patients with prostate cancer seen in the VA, which similarly demonstrate equal outcomes with those of other races.^28,36 Incorporation of the earlier mentioned VA services into oncologic care across other health care systems could better characterize determinants of racial disparities in prostate cancer, including the prognostic significance of shortening treatment duration and number of patient visits via MHRT.

Limitations

This study has several inherent limitations. While the size of the current HRPC cohort is notably larger than similar populations within the majority of phase 3 MHRT trials, these data derive from a single VA hospital. It is unclear whether these outcomes would be representative in a similar high-risk population receiving care outside of the VA equal access system. Follow-up data beyond 5 years was available for less than half of patients, partially due to nonprostate cancer–related mortality at a higher rate than observed in HRPC trial populations.^12,15,16 Furthermore, all GI toxicity events were exclusively physician reported, and GU toxicity reporting was limited in the off-trial setting with not all patients routinely completing IPSS questionnaires following MHRT completion. However, all patients were treated similarly, and radiation quality was verified over the treatment period with mandated accreditation, frequent standardized output checks, and systematic treatment review.³⁹

Conclusions

Patients with HRPC treated with MHRT in an equal access, off-trial setting demonstrated favorable rates of biochemical control with acceptable rates of acute and late GI and GU toxicities. Clinical outcomes, including biochemical control, were not significantly different between African American and White patients, which may reflect equal access to care within the VA irrespective of income and insurance status. Incorporating VA services, such as access to primary care, mental health services, and transportation across other health care systems may aid in characterizing and mitigating racial and gender disparities in oncologic care.  

Acknowledgments

Portions of this work were presented at the November 2020 ASTRO conference. ⁴⁰

Although moderately hypofractionated radiotherapy (MHRT) is an accepted treatment for localized prostate cancer, its adaptation remains limited in the United States.^1,2 MHRT theoretically exploits α/β ratio differences between the prostate (1.5 Gy), bladder (5-10 Gy), and rectum (3 Gy), thereby reducing late treatment-related adverse effects compared with those of conventional fractionation at biologically equivalent doses.^3-8 Multiple randomized noninferiority trials have demonstrated equivalent outcomes between MHRT and conventional fraction with no appreciable increase in patient-reported toxicity.^9-14 Although these studies have led to the acceptance of MHRT as a standard treatment, the majority of these trials involve individuals with low- and intermediate-risk disease.

There are less phase 3 data addressing MHRT for high-risk prostate cancer (HRPC).^10,12,14-17 Only 2 studies examined predominately high-risk populations, accounting for 83 and 292 patients, respectively.^15,16 Additional phase 3 trials with small proportions of high-risk patients (n = 126, 12%; n = 53, 35%) offer limited additional information regarding clinical outcomes and toxicity rates specific to high-risk disease.^10-12 Numerous phase 1 and 2 studies report various field designs and fractionation plans for MHRT in the context of high-risk disease, although the applicability of these data to off-trial populations remains limited.^18-20

Furthermore, African American individuals are underrepresented in the trials establishing the role of MHRT despite higher rates of prostate cancer incidence, more advanced disease stage at diagnosis, and higher rates of prostate cancer–specific survival (PCSS) when compared with White patients.²¹ Racial disparities across patients with prostate cancer and their management are multifactorial across health care literacy, education level, access to care (including transportation issues), and issues of adherence and distrust.^22-25 Correlation of patient race to prostate cancer outcomes varies greatly across health care systems, with the US Department of Veterans Affairs (VA) equal access system providing robust mental health services and transportation services for some patients, while demonstrating similar rates of stage-adjusted PCSS between African American and White patients across a broad range of treatment modalities.^26-28 Given the paucity of data exploring outcomes following MHRT for African American patients with HRPC, the present analysis provides long-term clinical outcomes and toxicity profiles for an off-trial majority African American population with HRPC treated with MHRT within the VA.

Methods

Records were retrospectively reviewed under an institutional review board–approved protocol for all patients with HRPC treated with definitive MHRT at the Durham Veterans Affairs Healthcare System in North Carolina between November 2008 and August 2018. Exclusion criteria included < 12 months of follow-up or elective nodal irradiation. Demographic variables obtained included age at diagnosis, race, clinical T stage, pre-MHRT prostate-specific antigen (PSA), Gleason grade group at diagnosis, favorable vs unfavorable high-risk disease, pre-MHRT international prostate symptom score (IPSS), and pre-MHRT urinary medication usage (yes/no).²⁹

Concurrent androgen deprivation therapy (ADT) was initiated 6 to 8 weeks before MHRT unless medically contraindicated per the discretion of the treating radiation oncologist. Patients generally received 18 to 24 months of ADT, with those with favorable HRPC (ie, T1c disease with either Gleason 4+4 and PSA < 10 mg/mL or Gleason 3+3 and PSA > 20 ng/mL) receiving 6 months after 2015.²⁹ Patients were simulated supine in either standard or custom immobilization with a full bladder and empty rectum. MHRT fractionation plans included 70 Gy at 2.5 Gy per fraction and 60 Gy at 3 Gy per fraction. Radiotherapy targets included the prostate and seminal vesicles without elective nodal coverage per institutional practice. Treatments were delivered following image guidance, either prostate matching with cone beam computed tomography or fiducial matching with kilo voltage imaging. All patients received intensity-modulated radiotherapy. For plans delivering 70 Gy at 2.5 Gy per fraction, constraints included bladder V (volume receiving) 70 < 10 cc, V65 ≤ 15%, V40 ≤ 35%, rectum V70 < 10 cc, V65 ≤ 10%, V40 ≤ 35%, femoral heads maximum point dose ≤ 40 Gy, penile bulb mean dose ≤ 50 Gy, and small bowel V40 ≤ 1%. For plans delivering 60 Gy at 3 Gy per fraction, constraints included rectum V57 ≤ 15%, V46 ≤ 30%, V37 ≤ 50%, bladder V60 ≤ 5%, V46 ≤ 30%, V37 ≤ 50%, and femoral heads V43 ≤ 5%.

Gastrointestinal (GI) and genitourinary (GU) toxicities were graded using Common Terminology Criteria for Adverse Events (CTCAE), version 5.0, with acute toxicity defined as on-treatment < 3 months following completion of MHRT. Late toxicity was defined as ≥ 3 months following completion of MHRT. Individuals were seen in follow-up at 6 weeks and 3 months with PSA and testosterone after MHRT completion, then every 6 to 12 months for 5 years and annually thereafter. Each follow-up visit included history, physical examination, IPSS, and CTCAE grading for GI and GU toxicity.

The Wilcoxon rank sum test and χ² test were used to compare differences in demographic data, dosimetric parameters, and frequency of toxicity events with respect to patient race. Clinical endpoints including biochemical recurrence-free survival (BRFS; defined by Phoenix criteria as 2.0 above PSA nadir), distant metastases-free survival (DMFS), PCSS, and overall survival (OS) were estimated from time of radiotherapy completion by the Kaplan-Meier method and compared between African American and White race by log-rank testing.³⁰ Late GI and GU toxicity-free survival were estimated by Kaplan-Meier plots and compared between African American and White patients by the log-rank test. Statistical analysis was performed using SAS 9.4.

Results

We identified 143 patients with HRPC treated with definitive MHRT between November 2008 and August 2018 (Table 1). Mean age was 65 years (range, 36-80 years); 57% were African American men. Eighty percent of individuals had unfavorable high-risk disease. Median (IQR) PSA was 14.4 (7.8-28.6). Twenty-six percent had grade group 1-3 disease, 47% had grade group 4 disease, and 27% had grade group 5 disease. African American patients had significantly lower pre-MHRT IPSS scores than White patients (mean IPSS, 11 vs 14, respectively; P = .02) despite similar rates of preradiotherapy urinary medication usage (66% and 66%, respectively).

Eighty-six percent received 70 Gy over 28 fractions, with institutional protocol shifting to 60 Gy over 20 fractions (14%) in June 2017. The median (IQR) duration of radiotherapy was 39 (38-42) days, with 97% of individuals undergoing ADT for a median (IQR) duration of 24 (24-36) months. The median follow-up time was 38 months, with 57 (40%) patients followed for at least 60 months.

Grade 3 GI and GU acute toxicity events were observed in 1% and 4% of all individuals, respectively (Table 2). No acute GI or GU grade 4+ events were observed. No significant differences in acute GU or GI toxicity were observed between African American and White patients.

Discussion

In this study, we reported acute and late GI and GU toxicity rates as well as clinical outcomes for a majority African American population with predominately unfavorable HRPC treated with MHRT in an equal access health care environment. We found that MHRT was well tolerated with high rates of biochemical control, PCSS, and OS. Additionally, outcomes were not significantly different across patient race. To our knowledge, this is the first report of MHRT for HRPC in a majority African American population.

We found that MHRT was an effective treatment for patients with HRPC, in particular those with unfavorable high-risk disease. While prior prospective and randomized studies have investigated the use of MHRT, our series was larger than most and had a predominately unfavorable high-risk population.^12,15-17 Our biochemical and PCSS rates compare favorably with those of HRPC trial populations, particularly given the high proportion of unfavorable high-risk disease.^12,15,16 Despite similar rates of biochemical control, OS was lower in the present cohort than in HRPC trial populations, even with a younger median age at diagnosis. The similarly high rates of non–HRPC-related death across race may reflect differences in baseline comorbidities compared with trial populations as well as reported differences between individuals in the VA and the private sector.³¹ This suggests that MHRT can be an effective treatment for patients with unfavorable HRPC.

We did not find any differences in outcomes between African American and White individuals with HRPC treated with MHRT. Furthermore, our study demonstrates long-term rates of BRFS and PCSS in a majority African American population with predominately unfavorable HRPC that are comparable with those of prior randomized MHRT studies in high-risk, predominately White populations.^12,15,16 Prior reports have found that African American men with HRPC may be at increased risk for inferior clinical outcomes due to a number of socioeconomic, biologic, and cultural mediators.^26,27,32 Such individuals may disproportionally benefit from shorter treatment courses that improve access to radiotherapy, a well-documented disparity for African American men with localized prostate cancer.^33-36 The VA is an ideal system for studying racial disparities within prostate cancer, as accessibility of mental health and transportation services, income, and insurance status are not barriers to preventative or acute care.³⁷ Our results are concordant with those previously seen for African American patients with prostate cancer seen in the VA, which similarly demonstrate equal outcomes with those of other races.^28,36 Incorporation of the earlier mentioned VA services into oncologic care across other health care systems could better characterize determinants of racial disparities in prostate cancer, including the prognostic significance of shortening treatment duration and number of patient visits via MHRT.

Limitations

This study has several inherent limitations. While the size of the current HRPC cohort is notably larger than similar populations within the majority of phase 3 MHRT trials, these data derive from a single VA hospital. It is unclear whether these outcomes would be representative in a similar high-risk population receiving care outside of the VA equal access system. Follow-up data beyond 5 years was available for less than half of patients, partially due to nonprostate cancer–related mortality at a higher rate than observed in HRPC trial populations.^12,15,16 Furthermore, all GI toxicity events were exclusively physician reported, and GU toxicity reporting was limited in the off-trial setting with not all patients routinely completing IPSS questionnaires following MHRT completion. However, all patients were treated similarly, and radiation quality was verified over the treatment period with mandated accreditation, frequent standardized output checks, and systematic treatment review.³⁹

Conclusions

Patients with HRPC treated with MHRT in an equal access, off-trial setting demonstrated favorable rates of biochemical control with acceptable rates of acute and late GI and GU toxicities. Clinical outcomes, including biochemical control, were not significantly different between African American and White patients, which may reflect equal access to care within the VA irrespective of income and insurance status. Incorporating VA services, such as access to primary care, mental health services, and transportation across other health care systems may aid in characterizing and mitigating racial and gender disparities in oncologic care.  

Acknowledgments

Portions of this work were presented at the November 2020 ASTRO conference. ⁴⁰

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Both a Wood lamp examination and a potassium hydroxide (KOH) prep returned negative results. Those findings, combined with the patient’s month-long antifungal medication adherence, helped to rule out other diagnoses. Based on history and examination, the patient was diagnosed with erythrasma.

Erythrasma is a skin infection caused by the gram-positive bacteria Corynebacterium minutissimum¹ that usually manifests in moist intertriginous areas. Sometimes it is secondary to fungal or yeast infections, local skin irritation due to friction, or due to maceration of the skin from persistent moisture. The Wood lamp examination can show coral-red fluorescence in erythrasma, but recent bathing (as in this case) may limit this finding.¹

The differential diagnosis of erythematous plaques in an intertriginous area includes inverse psoriasis. However, this patient had no nail changes, joint difficulties, or other rashes consistent with psoriasis. Macerated, erythematous inflammatory changes in intertriginous areas are always concerning for fungal infections (eg, yeast infection, tinea corporis), especially with the presence of any scale. In this case, the patient’s medication regimen helped to rule out these types of conditions.

First-line therapy for erythrasma includes topical antibiotics: clindamycin, erythromycin, mupirocin, and fusidic acid. Systemic antibiotics in the tetracycline family and macrolides may also be used but have a higher risk of adverse effects. Keeping the affected area dry is a useful adjunct to pharmacologic therapy.

The patient was treated with topical clindamycin bid for 7 days. By her 2-month follow-up appointment, there were no residual skin changes. Had the plaques persisted, the possibility of inverse psoriasis would have been revisited, with either presumptive treatment prescribed or biopsy performed to establish the diagnosis.

‌

Photo courtesy of Daniel Stulberg, MD. Text courtesy of Daniel Stulberg, MD, FAAFP, Department of Family and Community Medicine, University of New Mexico School of Medicine, Albuquerque.

Both a Wood lamp examination and a potassium hydroxide (KOH) prep returned negative results. Those findings, combined with the patient’s month-long antifungal medication adherence, helped to rule out other diagnoses. Based on history and examination, the patient was diagnosed with erythrasma.

Erythrasma is a skin infection caused by the gram-positive bacteria Corynebacterium minutissimum¹ that usually manifests in moist intertriginous areas. Sometimes it is secondary to fungal or yeast infections, local skin irritation due to friction, or due to maceration of the skin from persistent moisture. The Wood lamp examination can show coral-red fluorescence in erythrasma, but recent bathing (as in this case) may limit this finding.¹

The differential diagnosis of erythematous plaques in an intertriginous area includes inverse psoriasis. However, this patient had no nail changes, joint difficulties, or other rashes consistent with psoriasis. Macerated, erythematous inflammatory changes in intertriginous areas are always concerning for fungal infections (eg, yeast infection, tinea corporis), especially with the presence of any scale. In this case, the patient’s medication regimen helped to rule out these types of conditions.

First-line therapy for erythrasma includes topical antibiotics: clindamycin, erythromycin, mupirocin, and fusidic acid. Systemic antibiotics in the tetracycline family and macrolides may also be used but have a higher risk of adverse effects. Keeping the affected area dry is a useful adjunct to pharmacologic therapy.

The patient was treated with topical clindamycin bid for 7 days. By her 2-month follow-up appointment, there were no residual skin changes. Had the plaques persisted, the possibility of inverse psoriasis would have been revisited, with either presumptive treatment prescribed or biopsy performed to establish the diagnosis.

‌

Photo courtesy of Daniel Stulberg, MD. Text courtesy of Daniel Stulberg, MD, FAAFP, Department of Family and Community Medicine, University of New Mexico School of Medicine, Albuquerque.

Both a Wood lamp examination and a potassium hydroxide (KOH) prep returned negative results. Those findings, combined with the patient’s month-long antifungal medication adherence, helped to rule out other diagnoses. Based on history and examination, the patient was diagnosed with erythrasma.

Erythrasma is a skin infection caused by the gram-positive bacteria Corynebacterium minutissimum¹ that usually manifests in moist intertriginous areas. Sometimes it is secondary to fungal or yeast infections, local skin irritation due to friction, or due to maceration of the skin from persistent moisture. The Wood lamp examination can show coral-red fluorescence in erythrasma, but recent bathing (as in this case) may limit this finding.¹

The differential diagnosis of erythematous plaques in an intertriginous area includes inverse psoriasis. However, this patient had no nail changes, joint difficulties, or other rashes consistent with psoriasis. Macerated, erythematous inflammatory changes in intertriginous areas are always concerning for fungal infections (eg, yeast infection, tinea corporis), especially with the presence of any scale. In this case, the patient’s medication regimen helped to rule out these types of conditions.

First-line therapy for erythrasma includes topical antibiotics: clindamycin, erythromycin, mupirocin, and fusidic acid. Systemic antibiotics in the tetracycline family and macrolides may also be used but have a higher risk of adverse effects. Keeping the affected area dry is a useful adjunct to pharmacologic therapy.

The patient was treated with topical clindamycin bid for 7 days. By her 2-month follow-up appointment, there were no residual skin changes. Had the plaques persisted, the possibility of inverse psoriasis would have been revisited, with either presumptive treatment prescribed or biopsy performed to establish the diagnosis.

‌

Photo courtesy of Daniel Stulberg, MD. Text courtesy of Daniel Stulberg, MD, FAAFP, Department of Family and Community Medicine, University of New Mexico School of Medicine, Albuquerque.

Acute generalized pustular psoriasis (GPP) is a rare severe variant of psoriasis characterized by the sudden widespread eruption of sterile pustules.^1,2 The cutaneous manifestations of GPP also may be accompanied by signs of systemic inflammation, including fever, malaise, and leukocytosis.² Complications are common and may be life-threatening, especially in older patients with comorbid diseases.³ Generalized pustular psoriasis most commonly occurs in patients with a preceding history of psoriasis, but it also may occur de novo.⁴ Generalized pustular psoriasis is associated with notable morbidity and mortality, and relapses are common.^3,4 Many triggers of GPP have been identified, including initiation and withdrawal of various medications, infections, pregnancy, and other conditions.^5,6 Although GPP most often occurs in adults, it also may arise in children and infants.³ In pregnancy, GPP is referred to as impetigo herpetiformis, despite having no etiologic ties with either herpes simplex virus or staphylococcal or streptococcal infection. Impetigo herpetiformis is considered one of the most dangerous dermatoses of pregnancy because of high rates of associated maternal and fetal morbidity.^6,7

Acute GPP has proven to be a challenging disease to treat due to the rarity and relapsing-remitting nature of the disease; additionally, there are relatively few randomized controlled trials investigating the efficacy and safety of treatments for GPP. This review summarizes the features of GPP, including the pathophysiology of the disease, clinical and histological manifestations, and recommendations for management based on a PubMed search of articles indexed for MEDLINE using MeSH terms pertaining to the disease, including generalized pustular psoriasis, impetigo herpetiformis, and von Zumbusch psoriasis.

Pathophysiology

The pathophysiology of GPP is only partially understood, but it is thought to have a distinct pattern of immune activation compared with plaque psoriasis.⁸ Although there is a considerable amount of overlap and cross-talk among cytokine pathways, GPP generally is driven by innate immunity and unrestrained IL-36 cytokine activity. In contrast, adaptive immune responses—namely the tumor necrosis factor (TNF) α, IL-23, IL-17, and IL-22 axes—underlie plaque psoriasis.^8-10

Proinflammatory IL-36 cytokines α, β, and γ, which are all part of the IL-1 superfamily, bind to the IL-36 receptor (IL-36R) to recruit and activate immune cells via various mediators, including IL-1β; IL-8; and chemokines CXCL1, CXCL2, and CXCL8.³ The IL-36 receptor antagonist (IL-36ra) acts to inhibit this inflammatory cascade.^3,8 Microarray analyses of skin biopsy samples have shown that overexpression of IL-17A, TNF-α, IL-1, and IL-36 are seen in both GPP and plaque psoriasis lesions, but GPP lesions had higher expression of IL-1β, IL-36α, and IL-36γ and elevated neutrophil chemokines—CXCL1, CXCL2, and CXCL8—compared with plaque psoriasis lesions.⁸

Gene Mutations Associated With GPP

There are 3 gene mutations that have been associated with pustular variants of psoriasis, though these mutations account for a minority of cases of GPP.⁴ Genetic screenings are not routinely indicated in patients with GPP, but they may be warranted in severe cases when a familial pattern of inheritance is suspected.⁴

IL36RN—The gene IL36RN codes the anti-inflammatory IL-36ra. Loss-of-function mutations in IL36RN lead to impairment of IL-36ra and consequently hyperactivity of the proinflammatory responses triggered by IL-36.³ Homozygous and heterozygous mutations in IL36RN have been observed in both familial and sporadic cases of GPP.^11-13 Subsequent retrospective analyses have identified the presence of IL36RN mutations in patients with GPP with frequencies ranging from 23% to 37%.^14-17IL36RN mutations are thought to be more common in patients without concomitant plaque psoriasis and have been associated with severe disease and early disease onset.¹⁵

CARD14—A gain-of-function mutation in CARD14 results in overactivation of the proinflammatory nuclear factor κB pathway and has been implicated in cases of GPP with concurrent psoriasis vulgaris. Interestingly, this may suggest distinct etiologies underlying GPP de novo and GPP in patients with a history of psoriasis.^18,19

AP1S3—A loss-of-function mutation in AP1S3 results in abnormal endosomal trafficking and autophagy as well as increased expression of IL-36α.^20,21

Clinical Presentation and DiagnosisCutaneous Manifestations of GPP

Generalized pustular psoriasis is characterized by the onset of widespread 2- to 3-mm sterile pustules on erythematous skin or within psoriasiform plaques⁴ (Figure). In patients with skin of color, the erythema may appear less obvious or perhaps slightly violaceous compared to White skin. Pustules may coalesce to form “lakes” of pus.⁵ Cutaneous symptoms include pain, burning, and pruritus. Associated mucosal findings may include cheilitis, geographic tongue, conjunctivitis, and uveitis.⁴

The severity of symptoms can vary greatly among patients as well as between flares within the same patient.^2,3 Four distinct patterns of GPP have been described. The von Zumbusch pattern is characterized by a rapid, generalized, painful, erythematous and pustular eruption accompanied by fever and asthenia. The pustules usually resolve after several days with extensive scaling. The annular pattern is characterized by annular, erythematous, scaly lesions with pustules present centrifugally. The lesions enlarge by centrifugal expansion over a period of hours to days, while healing occurs centrally. The exanthematic type is an acute eruption of small pustules that abruptly appear and disappear within a few days, usually from infection or medication initiation. Sometimes pustules appear within or at the edge of existing psoriatic plaques in a localized pattern—the fourth pattern—often following the exposure to irritants (eg, tars, anthralin).⁵

Impetigo Herpetiformis—Impetigo herpetiformis is a form of GPP associated with pregnancy. It generally presents early in the third trimester with symmetric erythematous plaques in flexural and intertriginous areas with pustules present at lesion margins. Lesions expand centrifugally, with pustulation present at the advancing edge.^6,7 Patients often are acutely ill with fever, delirium, vomiting, and tetany. Mucous membranes, including the tongue, mouth, and esophagus, also may be involved. The eruption typically resolves after delivery, though it often recurs with subsequent pregnancies, with the morbidity risk rising with each successive pregnancy.⁷

Systemic and Extracutaneous Manifestations of GPP

Although the severity of GPP is highly variable, skin manifestations often are accompanied by systemic manifestations of inflammation, including fever and malaise. Common laboratory abnormalities include leukocytosis with peripheral neutrophilia, a high serum C-reactive protein level, hypocalcemia, and hypoalbuminemia.²² Abnormal liver enzymes often are present and result from neutrophilic cholangitis, with alternating strictures and dilations of biliary ducts observed on magnetic resonance imaging.²³ Additional laboratory abnormalities are provided in Table 2. Other extracutaneous findings associated with GPP include arthralgia, edema, and characteristic psoriatic nail changes.⁴ Fatal complications include acute respiratory distress syndrome, renal dysfunction, cardiovascular shock, and sepsis.^24,25

Histologic Features

Given the potential for the skin manifestations of GPP to mimic other disorders, a skin biopsy is warranted to confirm the diagnosis. Generalized pustular psoriasis is histologically characterized by the presence of subcorneal macropustules (ie, spongiform pustules of Kogoj) formed by neutrophil infiltration into the spongelike network of the epidermis.⁶ Otherwise, the architecture of the epithelium in GPP is similar to that seen with plaque psoriasis, with parakeratosis, acanthosis, rete-ridge elongation, diminished stratum granulosum, and thinning of the suprapapillary epidermis, though the inflammatory cell infiltrate and edema are markedly more severe in GPP than plaque psoriasis.^3,4

Differential Diagnosis

There are many other cutaneous pustular diagnoses that must be ruled out when evaluating a patient with GPP (Table 1).²⁶ Acute generalized exanthematous pustulosis (AGEP) is a common mimicker of GPP that is differentiated histologically by the presence of eosinophils and necrotic keratinocytes.⁴ In addition to its distinct histopathologic findings, AGEP is classically associated with recent initiation of certain medications, most commonly penicillins, macrolides, quinolones, sulfonamides, terbinafine, and diltiazem.²⁷ In contrast, GPP more commonly is related to withdrawal of corticosteroids as well as initiation of some biologic medications, including anti-TNF agents.³ Generalized pustular psoriasis should be suspected over AGEP in patients with a personal or family history of psoriasis, though GPP may arise in patients with or without a history of psoriasis. Acute generalized exanthematous pustulosis usually is more abrupt in both onset and resolution compared with GPP, with clearance of pustules within a few days to weeks following cessation of the triggering factor.⁴

Other pustular variants of psoriasis (eg, palmoplantar pustular psoriasis, acrodermatitis continua of Hallopeau) are differentiated from GPP by their chronicity and localization to palmoplantar and/or ungual surfaces.⁵ Other differential diagnoses are listed in Table 1.

Diagnostic Criteria for GPP

Diagnostic criteria have been proposed for GPP (Table 2), including (1) the presence of sterile pustules, (2) systemic signs of inflammation, (3) laboratory abnormalities, (4) histopathologic confirmation of spongiform pustules of Kogoj, and (5) recurrence of symptoms.²² To definitively diagnose GPP, all 5 criteria must be met. To rule out mimickers, it may be worthwhile to perform Gram staining, potassium hydroxide preparation, in vitro cultures, and/or immunofluorescence testing.⁶

Treatment

Given the high potential for mortality associated with GPP, the most essential component of management is to ensure adequate supportive care. Any temperature, fluid, or electrolyte imbalances should be corrected as they arise. Secondary infections also must be identified and treated, if present, to reduce the risk for fatal complications, including systemic infection and sepsis. Precautions must be taken to ensure that serious end-organ damage, including hepatic, renal, and respiratory dysfunction, is avoided.

Adjunctive topical intervention often is initiated with bland emollients, corticosteroids, calcineurin inhibitors, and/or vitamin D derivatives to help soothe skin symptoms, but treatment with systemic therapies usually is warranted to achieve symptom control.^2,25 Importantly, there are no systemic or topical agents that have specifically been approved for the treatment of GPP in Europe or the United States.³ Given the absence of universally accepted treatment guidelines, therapeutic agents for GPP usually are selected based on clinical experience while also taking the extent of involvement and disease severity into consideration.³

Treatment Recommendations for Adults

Oral Systemic Agents—Treatment guidelines set forth by the National Psoriasis Foundation (NPF) in 2012 proposed that first-line therapies for GPP should be acitretin, cyclosporine, methotrexate, and infliximab.²⁸ However, since those guidelines were established, many new biologic therapies have been approved for the treatment of psoriasis and often are considered in the treatment of psoriasis subtypes, including GPP.²⁹ Although retinoids previously were considered to be a preferred first-line therapy, they are associated with a high incidence of adverse effects and must be used with caution in women of childbearing age.⁶ Oral acitretin at a dosage of 0.75 to 1.0 mg/kg/d has been shown to result in clinical improvement within 1 to 2 weeks, and a maintenance dosage of 0.125 to 0.25 mg/kg/d is required for several months to prevent recurrence.³⁰ Methotrexate—5.0 to 15.0 mg/wk, or perhaps higher in patients with refractory disease, increased by 2.5-mg intervals until symptoms improve—is recommended by the NPF in patients who are unresponsive or cannot tolerate retinoids, though close monitoring for hematologic abnormalities is required. Cyclosporine 2.5 to 5.0 mg/kg/d is considered an alternative to methotrexate and retinoids; it has a faster onset of action, with improvement reported as early as 2 weeks after initiation of therapy.^1,28 Although cyclosporine may be effective in the acute phase, especially in severe cases of GPP, long-term use of cyclosporine is not recommended because of the potential for renal dysfunction and hypertension.³¹

Biologic Agents—More recent evidence has accumulated supporting the efficacy of anti-TNF agents in the treatment of GPP, suggesting the positioning of these agents as first line. A number of case series have shown dramatic and rapid improvement of GPP with intravenous infliximab 3 to 5 mg/kg, with results observed hours to days after the first infusion.^32-37 Thus, infliximab is recommended as first-line treatment in severe acute cases, though its efficacy as a maintenance therapy has not been sufficiently investigated.⁶ Case reports and case series document the safety and efficacy of adalimumab 40 to 80 mg every 1 to 2 weeks^38,39 and etanercept 25 to 50 mg twice weekly^40-42 in patients with recalcitrantGPP. Therefore, these anti-TNF agents may be considered in patients who are nonresponsive to treatment with infliximab.

Rarely, there have been reports of paradoxical induction of GPP with the use of some anti-TNF agents,^43-45 which may be due to a cytokine imbalance characterized by unopposed IFN-α activation.⁶ In patients with a history of GPP after initiation of a biologic, treatment with agents from within the offending class should be avoided.

The IL-17A monoclonal antibodies secukinumab, ixekizumab, and brodalumab have been shown in open-label phase 3 studies to result in disease remission at 12 weeks.^46-48 Treatment with guselkumab, an IL-23 monoclonal antibody, also has demonstrated efficacy in patients with GPP.⁴⁹ Ustekinumab, an IL-12/23 inhibitor, in combination with acitretin also has been shown to be successful in achieving disease remission after a few weeks of treatment.⁵⁰

More recent case reports have shown the efficacy of IL-1 inhibitors including gevokizumab, canakinumab, and anakinra in achieving GPP clearance, though more prospective studies are needed to evaluate their efficacy.^51-53 Given the etiologic association between IL-1 disinhibition and GPP, future investigations of these therapies as well as those that target the IL-36 pathway may prove to be particularly interesting.

Phototherapy and Combination Therapies—Phototherapy may be considered as maintenance therapy after disease control is achieved, though it is not considered appropriate for acute cases.²⁸ Combination therapies with a biologic plus a nonbiologic systemic agent or alternating among various biologics may allow physicians to maximize benefits and minimize adverse effects in the long term, though there is insufficient evidence to suggest any specific combination treatment algorithm for GPP.²⁸

Treatment Recommendations for Pediatric Patients

Based on a small number of case series and case reports, the first-line treatment strategy for children with GPP is similar to adults. Given the notable adverse events of most oral systemic agents, biologic therapies may emerge as first-line therapy in the pediatric population as more evidence accumulates.²⁸

Treatment Recommendations for Pregnant Patients

Systemic corticosteroids are widely considered to be the first-line treatments for the management of impetigo herpetiformis.⁷ Low-dose prednisone (15–30 mg/d) usually is effective, but severe cases may require increasing the dosage to 60 mg/d.⁶ Given the potential for rebound flares upon withdrawal of systemic corticosteroids, these agents must be gradually tapered after the resolution of symptoms.

Certolizumab pegol also is an attractive option in pregnant patients with impetigo herpetiformis because of its favorable safety profile and negligible mother-to-infant transfer through the placenta or breast milk. It has been shown to be effective in treating GPP and impetigo herpetiformis during pregnancy in recently published case reports.^54,55 In refractory cases, other TNF-α inhibitors (eg, adalimumab, infliximab, etanercept) or cyclosporine may be considered. However, cautious medical monitoring is warranted, as little is known about the potential adverse effects of these agents to the mother and fetus.^28,56 Data from transplant recipients along with several case reports indicate that cyclosporine is not associated with an increased risk for adverse effects during pregnancy at a dose of 2 to 3 mg/kg.^57-59 Both methotrexate and retinoids are known teratogens and are therefore contraindicated in pregnant patients.⁵⁶

If pustules do not resolve in the postpartum period, patients should be treated with standard GPP therapies. However, long-term and population studies are lacking regarding the potential for infant exposure to systemic agents in breast milk. Therefore, the NPF recommends avoiding breastfeeding while taking systemic medications, if possible.⁵⁶

Limitations of Treatment Recommendations

The ability to generate an evidence-based treatment strategy for GPP is limited by a lack of high-quality studies investigating the efficacy and safety of treatments in patients with GPP due to the rarity and relapsing-remitting nature of the disease, which makes randomized controlled trials difficult to conduct. The quality of the available research is further limited by the lack of validated outcome measures to specifically assess improvements in patients with GPP, such that results are difficult to synthesize and compare among studies.³¹

Conclusion

Although limited, the available research suggests that treatment with various biologics, especially infliximab, is effective in achieving rapid clearance in patients with GPP. In general, biologics may be the most appropriate treatment option in patients with GPP given their relatively favorable safety profiles. Other oral systemic agents, including acitretin, cyclosporine, and methotrexate, have limited evidence to support their use in the acute phase, but their safety profiles often limit their utility in the long-term. Emerging evidence regarding the association of GPP with IL36RN mutations suggests a unique role for agents targeting the IL-36 or IL-1 pathways, though this has yet to be thoroughly investigated.

Acute generalized pustular psoriasis (GPP) is a rare severe variant of psoriasis characterized by the sudden widespread eruption of sterile pustules.^1,2 The cutaneous manifestations of GPP also may be accompanied by signs of systemic inflammation, including fever, malaise, and leukocytosis.² Complications are common and may be life-threatening, especially in older patients with comorbid diseases.³ Generalized pustular psoriasis most commonly occurs in patients with a preceding history of psoriasis, but it also may occur de novo.⁴ Generalized pustular psoriasis is associated with notable morbidity and mortality, and relapses are common.^3,4 Many triggers of GPP have been identified, including initiation and withdrawal of various medications, infections, pregnancy, and other conditions.^5,6 Although GPP most often occurs in adults, it also may arise in children and infants.³ In pregnancy, GPP is referred to as impetigo herpetiformis, despite having no etiologic ties with either herpes simplex virus or staphylococcal or streptococcal infection. Impetigo herpetiformis is considered one of the most dangerous dermatoses of pregnancy because of high rates of associated maternal and fetal morbidity.^6,7

Acute GPP has proven to be a challenging disease to treat due to the rarity and relapsing-remitting nature of the disease; additionally, there are relatively few randomized controlled trials investigating the efficacy and safety of treatments for GPP. This review summarizes the features of GPP, including the pathophysiology of the disease, clinical and histological manifestations, and recommendations for management based on a PubMed search of articles indexed for MEDLINE using MeSH terms pertaining to the disease, including generalized pustular psoriasis, impetigo herpetiformis, and von Zumbusch psoriasis.

Pathophysiology

The pathophysiology of GPP is only partially understood, but it is thought to have a distinct pattern of immune activation compared with plaque psoriasis.⁸ Although there is a considerable amount of overlap and cross-talk among cytokine pathways, GPP generally is driven by innate immunity and unrestrained IL-36 cytokine activity. In contrast, adaptive immune responses—namely the tumor necrosis factor (TNF) α, IL-23, IL-17, and IL-22 axes—underlie plaque psoriasis.^8-10

Proinflammatory IL-36 cytokines α, β, and γ, which are all part of the IL-1 superfamily, bind to the IL-36 receptor (IL-36R) to recruit and activate immune cells via various mediators, including IL-1β; IL-8; and chemokines CXCL1, CXCL2, and CXCL8.³ The IL-36 receptor antagonist (IL-36ra) acts to inhibit this inflammatory cascade.^3,8 Microarray analyses of skin biopsy samples have shown that overexpression of IL-17A, TNF-α, IL-1, and IL-36 are seen in both GPP and plaque psoriasis lesions, but GPP lesions had higher expression of IL-1β, IL-36α, and IL-36γ and elevated neutrophil chemokines—CXCL1, CXCL2, and CXCL8—compared with plaque psoriasis lesions.⁸

Gene Mutations Associated With GPP

There are 3 gene mutations that have been associated with pustular variants of psoriasis, though these mutations account for a minority of cases of GPP.⁴ Genetic screenings are not routinely indicated in patients with GPP, but they may be warranted in severe cases when a familial pattern of inheritance is suspected.⁴

IL36RN—The gene IL36RN codes the anti-inflammatory IL-36ra. Loss-of-function mutations in IL36RN lead to impairment of IL-36ra and consequently hyperactivity of the proinflammatory responses triggered by IL-36.³ Homozygous and heterozygous mutations in IL36RN have been observed in both familial and sporadic cases of GPP.^11-13 Subsequent retrospective analyses have identified the presence of IL36RN mutations in patients with GPP with frequencies ranging from 23% to 37%.^14-17IL36RN mutations are thought to be more common in patients without concomitant plaque psoriasis and have been associated with severe disease and early disease onset.¹⁵

CARD14—A gain-of-function mutation in CARD14 results in overactivation of the proinflammatory nuclear factor κB pathway and has been implicated in cases of GPP with concurrent psoriasis vulgaris. Interestingly, this may suggest distinct etiologies underlying GPP de novo and GPP in patients with a history of psoriasis.^18,19

AP1S3—A loss-of-function mutation in AP1S3 results in abnormal endosomal trafficking and autophagy as well as increased expression of IL-36α.^20,21

Clinical Presentation and DiagnosisCutaneous Manifestations of GPP

Generalized pustular psoriasis is characterized by the onset of widespread 2- to 3-mm sterile pustules on erythematous skin or within psoriasiform plaques⁴ (Figure). In patients with skin of color, the erythema may appear less obvious or perhaps slightly violaceous compared to White skin. Pustules may coalesce to form “lakes” of pus.⁵ Cutaneous symptoms include pain, burning, and pruritus. Associated mucosal findings may include cheilitis, geographic tongue, conjunctivitis, and uveitis.⁴

The severity of symptoms can vary greatly among patients as well as between flares within the same patient.^2,3 Four distinct patterns of GPP have been described. The von Zumbusch pattern is characterized by a rapid, generalized, painful, erythematous and pustular eruption accompanied by fever and asthenia. The pustules usually resolve after several days with extensive scaling. The annular pattern is characterized by annular, erythematous, scaly lesions with pustules present centrifugally. The lesions enlarge by centrifugal expansion over a period of hours to days, while healing occurs centrally. The exanthematic type is an acute eruption of small pustules that abruptly appear and disappear within a few days, usually from infection or medication initiation. Sometimes pustules appear within or at the edge of existing psoriatic plaques in a localized pattern—the fourth pattern—often following the exposure to irritants (eg, tars, anthralin).⁵

Impetigo Herpetiformis—Impetigo herpetiformis is a form of GPP associated with pregnancy. It generally presents early in the third trimester with symmetric erythematous plaques in flexural and intertriginous areas with pustules present at lesion margins. Lesions expand centrifugally, with pustulation present at the advancing edge.^6,7 Patients often are acutely ill with fever, delirium, vomiting, and tetany. Mucous membranes, including the tongue, mouth, and esophagus, also may be involved. The eruption typically resolves after delivery, though it often recurs with subsequent pregnancies, with the morbidity risk rising with each successive pregnancy.⁷

Systemic and Extracutaneous Manifestations of GPP

Although the severity of GPP is highly variable, skin manifestations often are accompanied by systemic manifestations of inflammation, including fever and malaise. Common laboratory abnormalities include leukocytosis with peripheral neutrophilia, a high serum C-reactive protein level, hypocalcemia, and hypoalbuminemia.²² Abnormal liver enzymes often are present and result from neutrophilic cholangitis, with alternating strictures and dilations of biliary ducts observed on magnetic resonance imaging.²³ Additional laboratory abnormalities are provided in Table 2. Other extracutaneous findings associated with GPP include arthralgia, edema, and characteristic psoriatic nail changes.⁴ Fatal complications include acute respiratory distress syndrome, renal dysfunction, cardiovascular shock, and sepsis.^24,25

Histologic Features

Given the potential for the skin manifestations of GPP to mimic other disorders, a skin biopsy is warranted to confirm the diagnosis. Generalized pustular psoriasis is histologically characterized by the presence of subcorneal macropustules (ie, spongiform pustules of Kogoj) formed by neutrophil infiltration into the spongelike network of the epidermis.⁶ Otherwise, the architecture of the epithelium in GPP is similar to that seen with plaque psoriasis, with parakeratosis, acanthosis, rete-ridge elongation, diminished stratum granulosum, and thinning of the suprapapillary epidermis, though the inflammatory cell infiltrate and edema are markedly more severe in GPP than plaque psoriasis.^3,4

Differential Diagnosis

There are many other cutaneous pustular diagnoses that must be ruled out when evaluating a patient with GPP (Table 1).²⁶ Acute generalized exanthematous pustulosis (AGEP) is a common mimicker of GPP that is differentiated histologically by the presence of eosinophils and necrotic keratinocytes.⁴ In addition to its distinct histopathologic findings, AGEP is classically associated with recent initiation of certain medications, most commonly penicillins, macrolides, quinolones, sulfonamides, terbinafine, and diltiazem.²⁷ In contrast, GPP more commonly is related to withdrawal of corticosteroids as well as initiation of some biologic medications, including anti-TNF agents.³ Generalized pustular psoriasis should be suspected over AGEP in patients with a personal or family history of psoriasis, though GPP may arise in patients with or without a history of psoriasis. Acute generalized exanthematous pustulosis usually is more abrupt in both onset and resolution compared with GPP, with clearance of pustules within a few days to weeks following cessation of the triggering factor.⁴

Other pustular variants of psoriasis (eg, palmoplantar pustular psoriasis, acrodermatitis continua of Hallopeau) are differentiated from GPP by their chronicity and localization to palmoplantar and/or ungual surfaces.⁵ Other differential diagnoses are listed in Table 1.

Diagnostic Criteria for GPP

Diagnostic criteria have been proposed for GPP (Table 2), including (1) the presence of sterile pustules, (2) systemic signs of inflammation, (3) laboratory abnormalities, (4) histopathologic confirmation of spongiform pustules of Kogoj, and (5) recurrence of symptoms.²² To definitively diagnose GPP, all 5 criteria must be met. To rule out mimickers, it may be worthwhile to perform Gram staining, potassium hydroxide preparation, in vitro cultures, and/or immunofluorescence testing.⁶

Treatment

Given the high potential for mortality associated with GPP, the most essential component of management is to ensure adequate supportive care. Any temperature, fluid, or electrolyte imbalances should be corrected as they arise. Secondary infections also must be identified and treated, if present, to reduce the risk for fatal complications, including systemic infection and sepsis. Precautions must be taken to ensure that serious end-organ damage, including hepatic, renal, and respiratory dysfunction, is avoided.

Adjunctive topical intervention often is initiated with bland emollients, corticosteroids, calcineurin inhibitors, and/or vitamin D derivatives to help soothe skin symptoms, but treatment with systemic therapies usually is warranted to achieve symptom control.^2,25 Importantly, there are no systemic or topical agents that have specifically been approved for the treatment of GPP in Europe or the United States.³ Given the absence of universally accepted treatment guidelines, therapeutic agents for GPP usually are selected based on clinical experience while also taking the extent of involvement and disease severity into consideration.³

Treatment Recommendations for Adults

Oral Systemic Agents—Treatment guidelines set forth by the National Psoriasis Foundation (NPF) in 2012 proposed that first-line therapies for GPP should be acitretin, cyclosporine, methotrexate, and infliximab.²⁸ However, since those guidelines were established, many new biologic therapies have been approved for the treatment of psoriasis and often are considered in the treatment of psoriasis subtypes, including GPP.²⁹ Although retinoids previously were considered to be a preferred first-line therapy, they are associated with a high incidence of adverse effects and must be used with caution in women of childbearing age.⁶ Oral acitretin at a dosage of 0.75 to 1.0 mg/kg/d has been shown to result in clinical improvement within 1 to 2 weeks, and a maintenance dosage of 0.125 to 0.25 mg/kg/d is required for several months to prevent recurrence.³⁰ Methotrexate—5.0 to 15.0 mg/wk, or perhaps higher in patients with refractory disease, increased by 2.5-mg intervals until symptoms improve—is recommended by the NPF in patients who are unresponsive or cannot tolerate retinoids, though close monitoring for hematologic abnormalities is required. Cyclosporine 2.5 to 5.0 mg/kg/d is considered an alternative to methotrexate and retinoids; it has a faster onset of action, with improvement reported as early as 2 weeks after initiation of therapy.^1,28 Although cyclosporine may be effective in the acute phase, especially in severe cases of GPP, long-term use of cyclosporine is not recommended because of the potential for renal dysfunction and hypertension.³¹

Biologic Agents—More recent evidence has accumulated supporting the efficacy of anti-TNF agents in the treatment of GPP, suggesting the positioning of these agents as first line. A number of case series have shown dramatic and rapid improvement of GPP with intravenous infliximab 3 to 5 mg/kg, with results observed hours to days after the first infusion.^32-37 Thus, infliximab is recommended as first-line treatment in severe acute cases, though its efficacy as a maintenance therapy has not been sufficiently investigated.⁶ Case reports and case series document the safety and efficacy of adalimumab 40 to 80 mg every 1 to 2 weeks^38,39 and etanercept 25 to 50 mg twice weekly^40-42 in patients with recalcitrantGPP. Therefore, these anti-TNF agents may be considered in patients who are nonresponsive to treatment with infliximab.

Rarely, there have been reports of paradoxical induction of GPP with the use of some anti-TNF agents,^43-45 which may be due to a cytokine imbalance characterized by unopposed IFN-α activation.⁶ In patients with a history of GPP after initiation of a biologic, treatment with agents from within the offending class should be avoided.

The IL-17A monoclonal antibodies secukinumab, ixekizumab, and brodalumab have been shown in open-label phase 3 studies to result in disease remission at 12 weeks.^46-48 Treatment with guselkumab, an IL-23 monoclonal antibody, also has demonstrated efficacy in patients with GPP.⁴⁹ Ustekinumab, an IL-12/23 inhibitor, in combination with acitretin also has been shown to be successful in achieving disease remission after a few weeks of treatment.⁵⁰

More recent case reports have shown the efficacy of IL-1 inhibitors including gevokizumab, canakinumab, and anakinra in achieving GPP clearance, though more prospective studies are needed to evaluate their efficacy.^51-53 Given the etiologic association between IL-1 disinhibition and GPP, future investigations of these therapies as well as those that target the IL-36 pathway may prove to be particularly interesting.

Phototherapy and Combination Therapies—Phototherapy may be considered as maintenance therapy after disease control is achieved, though it is not considered appropriate for acute cases.²⁸ Combination therapies with a biologic plus a nonbiologic systemic agent or alternating among various biologics may allow physicians to maximize benefits and minimize adverse effects in the long term, though there is insufficient evidence to suggest any specific combination treatment algorithm for GPP.²⁸

Treatment Recommendations for Pediatric Patients

Based on a small number of case series and case reports, the first-line treatment strategy for children with GPP is similar to adults. Given the notable adverse events of most oral systemic agents, biologic therapies may emerge as first-line therapy in the pediatric population as more evidence accumulates.²⁸

Treatment Recommendations for Pregnant Patients

Systemic corticosteroids are widely considered to be the first-line treatments for the management of impetigo herpetiformis.⁷ Low-dose prednisone (15–30 mg/d) usually is effective, but severe cases may require increasing the dosage to 60 mg/d.⁶ Given the potential for rebound flares upon withdrawal of systemic corticosteroids, these agents must be gradually tapered after the resolution of symptoms.

Certolizumab pegol also is an attractive option in pregnant patients with impetigo herpetiformis because of its favorable safety profile and negligible mother-to-infant transfer through the placenta or breast milk. It has been shown to be effective in treating GPP and impetigo herpetiformis during pregnancy in recently published case reports.^54,55 In refractory cases, other TNF-α inhibitors (eg, adalimumab, infliximab, etanercept) or cyclosporine may be considered. However, cautious medical monitoring is warranted, as little is known about the potential adverse effects of these agents to the mother and fetus.^28,56 Data from transplant recipients along with several case reports indicate that cyclosporine is not associated with an increased risk for adverse effects during pregnancy at a dose of 2 to 3 mg/kg.^57-59 Both methotrexate and retinoids are known teratogens and are therefore contraindicated in pregnant patients.⁵⁶

If pustules do not resolve in the postpartum period, patients should be treated with standard GPP therapies. However, long-term and population studies are lacking regarding the potential for infant exposure to systemic agents in breast milk. Therefore, the NPF recommends avoiding breastfeeding while taking systemic medications, if possible.⁵⁶

Limitations of Treatment Recommendations

The ability to generate an evidence-based treatment strategy for GPP is limited by a lack of high-quality studies investigating the efficacy and safety of treatments in patients with GPP due to the rarity and relapsing-remitting nature of the disease, which makes randomized controlled trials difficult to conduct. The quality of the available research is further limited by the lack of validated outcome measures to specifically assess improvements in patients with GPP, such that results are difficult to synthesize and compare among studies.³¹

Conclusion

Although limited, the available research suggests that treatment with various biologics, especially infliximab, is effective in achieving rapid clearance in patients with GPP. In general, biologics may be the most appropriate treatment option in patients with GPP given their relatively favorable safety profiles. Other oral systemic agents, including acitretin, cyclosporine, and methotrexate, have limited evidence to support their use in the acute phase, but their safety profiles often limit their utility in the long-term. Emerging evidence regarding the association of GPP with IL36RN mutations suggests a unique role for agents targeting the IL-36 or IL-1 pathways, though this has yet to be thoroughly investigated.

Acute generalized pustular psoriasis (GPP) is a rare severe variant of psoriasis characterized by the sudden widespread eruption of sterile pustules.^1,2 The cutaneous manifestations of GPP also may be accompanied by signs of systemic inflammation, including fever, malaise, and leukocytosis.² Complications are common and may be life-threatening, especially in older patients with comorbid diseases.³ Generalized pustular psoriasis most commonly occurs in patients with a preceding history of psoriasis, but it also may occur de novo.⁴ Generalized pustular psoriasis is associated with notable morbidity and mortality, and relapses are common.^3,4 Many triggers of GPP have been identified, including initiation and withdrawal of various medications, infections, pregnancy, and other conditions.^5,6 Although GPP most often occurs in adults, it also may arise in children and infants.³ In pregnancy, GPP is referred to as impetigo herpetiformis, despite having no etiologic ties with either herpes simplex virus or staphylococcal or streptococcal infection. Impetigo herpetiformis is considered one of the most dangerous dermatoses of pregnancy because of high rates of associated maternal and fetal morbidity.^6,7

Acute GPP has proven to be a challenging disease to treat due to the rarity and relapsing-remitting nature of the disease; additionally, there are relatively few randomized controlled trials investigating the efficacy and safety of treatments for GPP. This review summarizes the features of GPP, including the pathophysiology of the disease, clinical and histological manifestations, and recommendations for management based on a PubMed search of articles indexed for MEDLINE using MeSH terms pertaining to the disease, including generalized pustular psoriasis, impetigo herpetiformis, and von Zumbusch psoriasis.

Pathophysiology

The pathophysiology of GPP is only partially understood, but it is thought to have a distinct pattern of immune activation compared with plaque psoriasis.⁸ Although there is a considerable amount of overlap and cross-talk among cytokine pathways, GPP generally is driven by innate immunity and unrestrained IL-36 cytokine activity. In contrast, adaptive immune responses—namely the tumor necrosis factor (TNF) α, IL-23, IL-17, and IL-22 axes—underlie plaque psoriasis.^8-10

Proinflammatory IL-36 cytokines α, β, and γ, which are all part of the IL-1 superfamily, bind to the IL-36 receptor (IL-36R) to recruit and activate immune cells via various mediators, including IL-1β; IL-8; and chemokines CXCL1, CXCL2, and CXCL8.³ The IL-36 receptor antagonist (IL-36ra) acts to inhibit this inflammatory cascade.^3,8 Microarray analyses of skin biopsy samples have shown that overexpression of IL-17A, TNF-α, IL-1, and IL-36 are seen in both GPP and plaque psoriasis lesions, but GPP lesions had higher expression of IL-1β, IL-36α, and IL-36γ and elevated neutrophil chemokines—CXCL1, CXCL2, and CXCL8—compared with plaque psoriasis lesions.⁸

Gene Mutations Associated With GPP

There are 3 gene mutations that have been associated with pustular variants of psoriasis, though these mutations account for a minority of cases of GPP.⁴ Genetic screenings are not routinely indicated in patients with GPP, but they may be warranted in severe cases when a familial pattern of inheritance is suspected.⁴

IL36RN—The gene IL36RN codes the anti-inflammatory IL-36ra. Loss-of-function mutations in IL36RN lead to impairment of IL-36ra and consequently hyperactivity of the proinflammatory responses triggered by IL-36.³ Homozygous and heterozygous mutations in IL36RN have been observed in both familial and sporadic cases of GPP.^11-13 Subsequent retrospective analyses have identified the presence of IL36RN mutations in patients with GPP with frequencies ranging from 23% to 37%.^14-17IL36RN mutations are thought to be more common in patients without concomitant plaque psoriasis and have been associated with severe disease and early disease onset.¹⁵

CARD14—A gain-of-function mutation in CARD14 results in overactivation of the proinflammatory nuclear factor κB pathway and has been implicated in cases of GPP with concurrent psoriasis vulgaris. Interestingly, this may suggest distinct etiologies underlying GPP de novo and GPP in patients with a history of psoriasis.^18,19

AP1S3—A loss-of-function mutation in AP1S3 results in abnormal endosomal trafficking and autophagy as well as increased expression of IL-36α.^20,21

Clinical Presentation and DiagnosisCutaneous Manifestations of GPP

Generalized pustular psoriasis is characterized by the onset of widespread 2- to 3-mm sterile pustules on erythematous skin or within psoriasiform plaques⁴ (Figure). In patients with skin of color, the erythema may appear less obvious or perhaps slightly violaceous compared to White skin. Pustules may coalesce to form “lakes” of pus.⁵ Cutaneous symptoms include pain, burning, and pruritus. Associated mucosal findings may include cheilitis, geographic tongue, conjunctivitis, and uveitis.⁴

The severity of symptoms can vary greatly among patients as well as between flares within the same patient.^2,3 Four distinct patterns of GPP have been described. The von Zumbusch pattern is characterized by a rapid, generalized, painful, erythematous and pustular eruption accompanied by fever and asthenia. The pustules usually resolve after several days with extensive scaling. The annular pattern is characterized by annular, erythematous, scaly lesions with pustules present centrifugally. The lesions enlarge by centrifugal expansion over a period of hours to days, while healing occurs centrally. The exanthematic type is an acute eruption of small pustules that abruptly appear and disappear within a few days, usually from infection or medication initiation. Sometimes pustules appear within or at the edge of existing psoriatic plaques in a localized pattern—the fourth pattern—often following the exposure to irritants (eg, tars, anthralin).⁵

Impetigo Herpetiformis—Impetigo herpetiformis is a form of GPP associated with pregnancy. It generally presents early in the third trimester with symmetric erythematous plaques in flexural and intertriginous areas with pustules present at lesion margins. Lesions expand centrifugally, with pustulation present at the advancing edge.^6,7 Patients often are acutely ill with fever, delirium, vomiting, and tetany. Mucous membranes, including the tongue, mouth, and esophagus, also may be involved. The eruption typically resolves after delivery, though it often recurs with subsequent pregnancies, with the morbidity risk rising with each successive pregnancy.⁷

Systemic and Extracutaneous Manifestations of GPP

Although the severity of GPP is highly variable, skin manifestations often are accompanied by systemic manifestations of inflammation, including fever and malaise. Common laboratory abnormalities include leukocytosis with peripheral neutrophilia, a high serum C-reactive protein level, hypocalcemia, and hypoalbuminemia.²² Abnormal liver enzymes often are present and result from neutrophilic cholangitis, with alternating strictures and dilations of biliary ducts observed on magnetic resonance imaging.²³ Additional laboratory abnormalities are provided in Table 2. Other extracutaneous findings associated with GPP include arthralgia, edema, and characteristic psoriatic nail changes.⁴ Fatal complications include acute respiratory distress syndrome, renal dysfunction, cardiovascular shock, and sepsis.^24,25

Histologic Features

Given the potential for the skin manifestations of GPP to mimic other disorders, a skin biopsy is warranted to confirm the diagnosis. Generalized pustular psoriasis is histologically characterized by the presence of subcorneal macropustules (ie, spongiform pustules of Kogoj) formed by neutrophil infiltration into the spongelike network of the epidermis.⁶ Otherwise, the architecture of the epithelium in GPP is similar to that seen with plaque psoriasis, with parakeratosis, acanthosis, rete-ridge elongation, diminished stratum granulosum, and thinning of the suprapapillary epidermis, though the inflammatory cell infiltrate and edema are markedly more severe in GPP than plaque psoriasis.^3,4

Differential Diagnosis

There are many other cutaneous pustular diagnoses that must be ruled out when evaluating a patient with GPP (Table 1).²⁶ Acute generalized exanthematous pustulosis (AGEP) is a common mimicker of GPP that is differentiated histologically by the presence of eosinophils and necrotic keratinocytes.⁴ In addition to its distinct histopathologic findings, AGEP is classically associated with recent initiation of certain medications, most commonly penicillins, macrolides, quinolones, sulfonamides, terbinafine, and diltiazem.²⁷ In contrast, GPP more commonly is related to withdrawal of corticosteroids as well as initiation of some biologic medications, including anti-TNF agents.³ Generalized pustular psoriasis should be suspected over AGEP in patients with a personal or family history of psoriasis, though GPP may arise in patients with or without a history of psoriasis. Acute generalized exanthematous pustulosis usually is more abrupt in both onset and resolution compared with GPP, with clearance of pustules within a few days to weeks following cessation of the triggering factor.⁴

Other pustular variants of psoriasis (eg, palmoplantar pustular psoriasis, acrodermatitis continua of Hallopeau) are differentiated from GPP by their chronicity and localization to palmoplantar and/or ungual surfaces.⁵ Other differential diagnoses are listed in Table 1.

Diagnostic Criteria for GPP

Diagnostic criteria have been proposed for GPP (Table 2), including (1) the presence of sterile pustules, (2) systemic signs of inflammation, (3) laboratory abnormalities, (4) histopathologic confirmation of spongiform pustules of Kogoj, and (5) recurrence of symptoms.²² To definitively diagnose GPP, all 5 criteria must be met. To rule out mimickers, it may be worthwhile to perform Gram staining, potassium hydroxide preparation, in vitro cultures, and/or immunofluorescence testing.⁶

Treatment

Given the high potential for mortality associated with GPP, the most essential component of management is to ensure adequate supportive care. Any temperature, fluid, or electrolyte imbalances should be corrected as they arise. Secondary infections also must be identified and treated, if present, to reduce the risk for fatal complications, including systemic infection and sepsis. Precautions must be taken to ensure that serious end-organ damage, including hepatic, renal, and respiratory dysfunction, is avoided.

Adjunctive topical intervention often is initiated with bland emollients, corticosteroids, calcineurin inhibitors, and/or vitamin D derivatives to help soothe skin symptoms, but treatment with systemic therapies usually is warranted to achieve symptom control.^2,25 Importantly, there are no systemic or topical agents that have specifically been approved for the treatment of GPP in Europe or the United States.³ Given the absence of universally accepted treatment guidelines, therapeutic agents for GPP usually are selected based on clinical experience while also taking the extent of involvement and disease severity into consideration.³

Treatment Recommendations for Adults

Oral Systemic Agents—Treatment guidelines set forth by the National Psoriasis Foundation (NPF) in 2012 proposed that first-line therapies for GPP should be acitretin, cyclosporine, methotrexate, and infliximab.²⁸ However, since those guidelines were established, many new biologic therapies have been approved for the treatment of psoriasis and often are considered in the treatment of psoriasis subtypes, including GPP.²⁹ Although retinoids previously were considered to be a preferred first-line therapy, they are associated with a high incidence of adverse effects and must be used with caution in women of childbearing age.⁶ Oral acitretin at a dosage of 0.75 to 1.0 mg/kg/d has been shown to result in clinical improvement within 1 to 2 weeks, and a maintenance dosage of 0.125 to 0.25 mg/kg/d is required for several months to prevent recurrence.³⁰ Methotrexate—5.0 to 15.0 mg/wk, or perhaps higher in patients with refractory disease, increased by 2.5-mg intervals until symptoms improve—is recommended by the NPF in patients who are unresponsive or cannot tolerate retinoids, though close monitoring for hematologic abnormalities is required. Cyclosporine 2.5 to 5.0 mg/kg/d is considered an alternative to methotrexate and retinoids; it has a faster onset of action, with improvement reported as early as 2 weeks after initiation of therapy.^1,28 Although cyclosporine may be effective in the acute phase, especially in severe cases of GPP, long-term use of cyclosporine is not recommended because of the potential for renal dysfunction and hypertension.³¹

Biologic Agents—More recent evidence has accumulated supporting the efficacy of anti-TNF agents in the treatment of GPP, suggesting the positioning of these agents as first line. A number of case series have shown dramatic and rapid improvement of GPP with intravenous infliximab 3 to 5 mg/kg, with results observed hours to days after the first infusion.^32-37 Thus, infliximab is recommended as first-line treatment in severe acute cases, though its efficacy as a maintenance therapy has not been sufficiently investigated.⁶ Case reports and case series document the safety and efficacy of adalimumab 40 to 80 mg every 1 to 2 weeks^38,39 and etanercept 25 to 50 mg twice weekly^40-42 in patients with recalcitrantGPP. Therefore, these anti-TNF agents may be considered in patients who are nonresponsive to treatment with infliximab.

Rarely, there have been reports of paradoxical induction of GPP with the use of some anti-TNF agents,^43-45 which may be due to a cytokine imbalance characterized by unopposed IFN-α activation.⁶ In patients with a history of GPP after initiation of a biologic, treatment with agents from within the offending class should be avoided.

The IL-17A monoclonal antibodies secukinumab, ixekizumab, and brodalumab have been shown in open-label phase 3 studies to result in disease remission at 12 weeks.^46-48 Treatment with guselkumab, an IL-23 monoclonal antibody, also has demonstrated efficacy in patients with GPP.⁴⁹ Ustekinumab, an IL-12/23 inhibitor, in combination with acitretin also has been shown to be successful in achieving disease remission after a few weeks of treatment.⁵⁰

More recent case reports have shown the efficacy of IL-1 inhibitors including gevokizumab, canakinumab, and anakinra in achieving GPP clearance, though more prospective studies are needed to evaluate their efficacy.^51-53 Given the etiologic association between IL-1 disinhibition and GPP, future investigations of these therapies as well as those that target the IL-36 pathway may prove to be particularly interesting.

Phototherapy and Combination Therapies—Phototherapy may be considered as maintenance therapy after disease control is achieved, though it is not considered appropriate for acute cases.²⁸ Combination therapies with a biologic plus a nonbiologic systemic agent or alternating among various biologics may allow physicians to maximize benefits and minimize adverse effects in the long term, though there is insufficient evidence to suggest any specific combination treatment algorithm for GPP.²⁸

Treatment Recommendations for Pediatric Patients

Based on a small number of case series and case reports, the first-line treatment strategy for children with GPP is similar to adults. Given the notable adverse events of most oral systemic agents, biologic therapies may emerge as first-line therapy in the pediatric population as more evidence accumulates.²⁸

Treatment Recommendations for Pregnant Patients

Systemic corticosteroids are widely considered to be the first-line treatments for the management of impetigo herpetiformis.⁷ Low-dose prednisone (15–30 mg/d) usually is effective, but severe cases may require increasing the dosage to 60 mg/d.⁶ Given the potential for rebound flares upon withdrawal of systemic corticosteroids, these agents must be gradually tapered after the resolution of symptoms.

Certolizumab pegol also is an attractive option in pregnant patients with impetigo herpetiformis because of its favorable safety profile and negligible mother-to-infant transfer through the placenta or breast milk. It has been shown to be effective in treating GPP and impetigo herpetiformis during pregnancy in recently published case reports.^54,55 In refractory cases, other TNF-α inhibitors (eg, adalimumab, infliximab, etanercept) or cyclosporine may be considered. However, cautious medical monitoring is warranted, as little is known about the potential adverse effects of these agents to the mother and fetus.^28,56 Data from transplant recipients along with several case reports indicate that cyclosporine is not associated with an increased risk for adverse effects during pregnancy at a dose of 2 to 3 mg/kg.^57-59 Both methotrexate and retinoids are known teratogens and are therefore contraindicated in pregnant patients.⁵⁶

If pustules do not resolve in the postpartum period, patients should be treated with standard GPP therapies. However, long-term and population studies are lacking regarding the potential for infant exposure to systemic agents in breast milk. Therefore, the NPF recommends avoiding breastfeeding while taking systemic medications, if possible.⁵⁶

Limitations of Treatment Recommendations

The ability to generate an evidence-based treatment strategy for GPP is limited by a lack of high-quality studies investigating the efficacy and safety of treatments in patients with GPP due to the rarity and relapsing-remitting nature of the disease, which makes randomized controlled trials difficult to conduct. The quality of the available research is further limited by the lack of validated outcome measures to specifically assess improvements in patients with GPP, such that results are difficult to synthesize and compare among studies.³¹

Conclusion

Although limited, the available research suggests that treatment with various biologics, especially infliximab, is effective in achieving rapid clearance in patients with GPP. In general, biologics may be the most appropriate treatment option in patients with GPP given their relatively favorable safety profiles. Other oral systemic agents, including acitretin, cyclosporine, and methotrexate, have limited evidence to support their use in the acute phase, but their safety profiles often limit their utility in the long-term. Emerging evidence regarding the association of GPP with IL36RN mutations suggests a unique role for agents targeting the IL-36 or IL-1 pathways, though this has yet to be thoroughly investigated.

To the Editor:

Psoriasis affects 2% to 3% of the US population and is one of the more commonly diagnosed dermatologic conditions.^1-3 Experts agree that common cutaneous diseases such as psoriasis present differently in patients with skin of color (SOC) compared to non-SOC patients.^3,4 Despite the prevalence of psoriasis, data on these morphologic differences are limited.^3-5 We performed a retrospective chart review comparing characteristics of psoriasis in SOC and non-SOC patients.

Through a search of electronic health records, we identified patients with an International Classification of Diseases, 10th Revision, diagnosis of psoriasis who were 18 years or older and were evaluated in the dermatology department between August 2015 and June 2020 at University Medical Center, an academic institution in New Orleans, Louisiana. Photographs and descriptions of lesions from these patients were reviewed. Patient data collected included age, sex, psoriasis classification, insurance status, self-identified race and ethnicity, location of lesion(s), biopsy, final diagnosis, and average number of visits or days required for accurate diagnosis. Self-identified SOC race and ethnicity categories included Black or African American, Hispanic, Asian, American Indian and Alaskan Native, Native Hawaiian and Other Pacific Islander, and “other.”

All analyses were conducted using R-4.0.1 statistics software. Categorical variables were compared in SOC and non-SOC groups using Fisher exact tests. Continuous covariates were conducted using a Wilcoxon rank sum test.

In total, we reviewed 557 charts. Four patients who declined to identify their race or ethnicity were excluded, yielding 286 SOC and 267 non-SOC patients (N=553). A total of 276 patients (131 SOC; 145 non-SOC) with a prior diagnosis of psoriasis were excluded in the days to diagnosis analysis. Twenty patients (15, SOC; 5, non-SOC) were given a diagnosis of a disease other than psoriasis when evaluated in the dermatology department.

Distributions between racial groups differed for insurance status, sex, psoriasis classification, biopsy status, and days between first dermatology visit and diagnosis. Skin of color patients had significantly longer days between initial presentation to dermatology and final diagnosis vs non-SOC patients (180.11 and 60.27 days, respectively; P=.001). Skin of color patients had a higher rate of palmoplantar psoriasis and severe plaque psoriasis (ie, >10% body surface area involvement) at presentation.

Several multivariable regression analyses were performed. Skin of color patients had significantly higher odds of biopsy compared to non-SOC patients (adjusted odds ratio [95% CI]=4 [2.05-7.82]; P<.001)(Figure 1). There were no significant predictors for severe plaque psoriasis involving more than 10% body surface area. Skin of color patients had a significantly longer time to diagnosis than non-SOC patients (P=.006)(Figure 2). On average, patients with SOC waited 3.23 times longer for a diagnosis than their non-SOC counterparts (95% CI, 1.42-7.36).

Our data reveal striking racial disparities in psoriasis care. Worse outcomes for patients with SOC compared to non-SOC patients may result from physicians’ inadequate familiarity with diverse presentations of psoriasis, including more frequent involvement of special body sites in SOC. Other likely contributing factors that we did not evaluate include socioeconomic barriers to health care, lack of physician diversity, missed appointments, and a paucity of literature on the topic of differentiating morphologies of psoriasis in SOC and non-SOC patients. Our study did not examine the effects of sex, tobacco use, or prior or current therapy, and it excluded pediatric patients.

To improve dermatologic outcomes for our increasingly diverse patient population, more studies must be undertaken to elucidate and document disparities in care for SOC populations.

To the Editor:

Psoriasis affects 2% to 3% of the US population and is one of the more commonly diagnosed dermatologic conditions.^1-3 Experts agree that common cutaneous diseases such as psoriasis present differently in patients with skin of color (SOC) compared to non-SOC patients.^3,4 Despite the prevalence of psoriasis, data on these morphologic differences are limited.^3-5 We performed a retrospective chart review comparing characteristics of psoriasis in SOC and non-SOC patients.

Through a search of electronic health records, we identified patients with an International Classification of Diseases, 10th Revision, diagnosis of psoriasis who were 18 years or older and were evaluated in the dermatology department between August 2015 and June 2020 at University Medical Center, an academic institution in New Orleans, Louisiana. Photographs and descriptions of lesions from these patients were reviewed. Patient data collected included age, sex, psoriasis classification, insurance status, self-identified race and ethnicity, location of lesion(s), biopsy, final diagnosis, and average number of visits or days required for accurate diagnosis. Self-identified SOC race and ethnicity categories included Black or African American, Hispanic, Asian, American Indian and Alaskan Native, Native Hawaiian and Other Pacific Islander, and “other.”

All analyses were conducted using R-4.0.1 statistics software. Categorical variables were compared in SOC and non-SOC groups using Fisher exact tests. Continuous covariates were conducted using a Wilcoxon rank sum test.

In total, we reviewed 557 charts. Four patients who declined to identify their race or ethnicity were excluded, yielding 286 SOC and 267 non-SOC patients (N=553). A total of 276 patients (131 SOC; 145 non-SOC) with a prior diagnosis of psoriasis were excluded in the days to diagnosis analysis. Twenty patients (15, SOC; 5, non-SOC) were given a diagnosis of a disease other than psoriasis when evaluated in the dermatology department.

Distributions between racial groups differed for insurance status, sex, psoriasis classification, biopsy status, and days between first dermatology visit and diagnosis. Skin of color patients had significantly longer days between initial presentation to dermatology and final diagnosis vs non-SOC patients (180.11 and 60.27 days, respectively; P=.001). Skin of color patients had a higher rate of palmoplantar psoriasis and severe plaque psoriasis (ie, >10% body surface area involvement) at presentation.

Several multivariable regression analyses were performed. Skin of color patients had significantly higher odds of biopsy compared to non-SOC patients (adjusted odds ratio [95% CI]=4 [2.05-7.82]; P<.001)(Figure 1). There were no significant predictors for severe plaque psoriasis involving more than 10% body surface area. Skin of color patients had a significantly longer time to diagnosis than non-SOC patients (P=.006)(Figure 2). On average, patients with SOC waited 3.23 times longer for a diagnosis than their non-SOC counterparts (95% CI, 1.42-7.36).

Our data reveal striking racial disparities in psoriasis care. Worse outcomes for patients with SOC compared to non-SOC patients may result from physicians’ inadequate familiarity with diverse presentations of psoriasis, including more frequent involvement of special body sites in SOC. Other likely contributing factors that we did not evaluate include socioeconomic barriers to health care, lack of physician diversity, missed appointments, and a paucity of literature on the topic of differentiating morphologies of psoriasis in SOC and non-SOC patients. Our study did not examine the effects of sex, tobacco use, or prior or current therapy, and it excluded pediatric patients.

To improve dermatologic outcomes for our increasingly diverse patient population, more studies must be undertaken to elucidate and document disparities in care for SOC populations.

To the Editor:

Psoriasis affects 2% to 3% of the US population and is one of the more commonly diagnosed dermatologic conditions.^1-3 Experts agree that common cutaneous diseases such as psoriasis present differently in patients with skin of color (SOC) compared to non-SOC patients.^3,4 Despite the prevalence of psoriasis, data on these morphologic differences are limited.^3-5 We performed a retrospective chart review comparing characteristics of psoriasis in SOC and non-SOC patients.

Through a search of electronic health records, we identified patients with an International Classification of Diseases, 10th Revision, diagnosis of psoriasis who were 18 years or older and were evaluated in the dermatology department between August 2015 and June 2020 at University Medical Center, an academic institution in New Orleans, Louisiana. Photographs and descriptions of lesions from these patients were reviewed. Patient data collected included age, sex, psoriasis classification, insurance status, self-identified race and ethnicity, location of lesion(s), biopsy, final diagnosis, and average number of visits or days required for accurate diagnosis. Self-identified SOC race and ethnicity categories included Black or African American, Hispanic, Asian, American Indian and Alaskan Native, Native Hawaiian and Other Pacific Islander, and “other.”

All analyses were conducted using R-4.0.1 statistics software. Categorical variables were compared in SOC and non-SOC groups using Fisher exact tests. Continuous covariates were conducted using a Wilcoxon rank sum test.

In total, we reviewed 557 charts. Four patients who declined to identify their race or ethnicity were excluded, yielding 286 SOC and 267 non-SOC patients (N=553). A total of 276 patients (131 SOC; 145 non-SOC) with a prior diagnosis of psoriasis were excluded in the days to diagnosis analysis. Twenty patients (15, SOC; 5, non-SOC) were given a diagnosis of a disease other than psoriasis when evaluated in the dermatology department.

Distributions between racial groups differed for insurance status, sex, psoriasis classification, biopsy status, and days between first dermatology visit and diagnosis. Skin of color patients had significantly longer days between initial presentation to dermatology and final diagnosis vs non-SOC patients (180.11 and 60.27 days, respectively; P=.001). Skin of color patients had a higher rate of palmoplantar psoriasis and severe plaque psoriasis (ie, >10% body surface area involvement) at presentation.

Several multivariable regression analyses were performed. Skin of color patients had significantly higher odds of biopsy compared to non-SOC patients (adjusted odds ratio [95% CI]=4 [2.05-7.82]; P<.001)(Figure 1). There were no significant predictors for severe plaque psoriasis involving more than 10% body surface area. Skin of color patients had a significantly longer time to diagnosis than non-SOC patients (P=.006)(Figure 2). On average, patients with SOC waited 3.23 times longer for a diagnosis than their non-SOC counterparts (95% CI, 1.42-7.36).

Our data reveal striking racial disparities in psoriasis care. Worse outcomes for patients with SOC compared to non-SOC patients may result from physicians’ inadequate familiarity with diverse presentations of psoriasis, including more frequent involvement of special body sites in SOC. Other likely contributing factors that we did not evaluate include socioeconomic barriers to health care, lack of physician diversity, missed appointments, and a paucity of literature on the topic of differentiating morphologies of psoriasis in SOC and non-SOC patients. Our study did not examine the effects of sex, tobacco use, or prior or current therapy, and it excluded pediatric patients.

To improve dermatologic outcomes for our increasingly diverse patient population, more studies must be undertaken to elucidate and document disparities in care for SOC populations.

Psoriasis is a chronic inflammatory skin disease characterized by erythematous scaly plaques that can invoke substantial pain, pruritus, and quality-of-life disturbance in patients. Topical therapies are the most commonly used medications for treating psoriasis, with one study (N = 128,308) showing that more than 85% of patients with psoriasis were managed solely with topical medications. ¹ For patients with mild to moderate psoriasis, topical agents alone may be able to control disease completely. For those with more severe disease, topical agents are used adjunctively with systemic or biologic agents to optimize disease control in localized areas.

The American Academy of Dermatology (AAD) and National Psoriasis Foundation (NPF) published guidelines in 2020 for managing psoriasis with topical agents in adults.² This review presents the most up-to-date clinical recommendations for topical agent use in adult patients with psoriasis and elaborates on each drug’s pharmacologic and safety profile. Specifically, evidence-based treatment recommendations for topical steroids, calcineurin inhibitors (CNIs), vitamin D analogues, retinoids (tazarotene), emollients, keratolytics (salicylic acid), anthracenes (anthralin), and keratoplastics (coal tar) will be addressed (Table 1). Recommendations for combination therapy with other treatment modalities including UVB light therapy, biologics, and systemic nonbiologic agents also will be discussed.

Selecting a Topical Agent Based on Disease Localization

When treating patients with psoriasis with topical therapies, clinicians should take into consideration drug potency, as it determines how effective a treatment will be in penetrating the skin barrier. Plaque characteristics, such as distribution (localized vs widespread), anatomical localization (flexural, scalp, palms/soles/nails), size (large vs small), and thickness (thick vs thin), not only influence treatment effectiveness but also the incidence of drug-related adverse events. Furthermore, preferred topical therapies are tailored to each patient based on disease characteristics and activity. Coal tar and anthralin have been used less frequently than other topical therapies for psoriasis because of their undesirable side-effect profiles (Table 1).³

Face and Intertriginous Regions—The face and intertriginous areas are sensitive because skin tends to be thin in these regions. Emollients are recommended for disease in these locations given their safety and flexibility in use for most areas. Conversely, anthralin should be avoided on the face, intertriginous areas, and even highly visible locations because of the potential for skin staining. Low-potency corticosteroids also have utility in psoriasis distributed on the face and intertriginous regions. Additionally, application of steroids around the eyes should be cautioned because topical steroids can induce ocular complications such as glaucoma and cataracts in rare circumstances.⁴

Off-label use of CNIs for psoriasis on the face and intertriginous areas also is effective. Currently, there is a level B recommendation for off-label use of 0.1% tacrolimus for up to 8 weeks for inverse psoriasis or psoriasis on the face. Off-label use of pimecrolimus for 4 to 8 weeks also can be considered for inverse psoriasis. Combination therapy consisting of hydrocortisone with calcipotriol ointment is another effective regimen.⁵ One study also suggested that use of crisaborole for 4 to 8 weeks in intertriginous psoriasis can be effective and well tolerated.⁶

Scalp—The vehicle of medication administration is especially important in hair-bearing areas such as the scalp, as these areas are challenging for medication application and patient adherence. Thus, patient preferences for the vehicle must be considered. Several studies have been conducted to assess preference for various vehicles in scalp psoriasis. A foam or solution may be preferable to ointments, gels, or creams.⁷ Gels may be preferred over ointments.⁸ There is a level A recommendation supporting the use of class 1 to 7 topical steroids for a minimum of 4 weeks as initial and maintenance treatment of scalp psoriasis. The highest level of evidence (level A) also supports the use of calcipotriol foam or combination therapy of calcipotriol–betamethasone dipropionate gel for 4 to 12 weeks as treatment of mild to moderate scalp psoriasis.

Nails—Several options for topical medications have been recommended for the treatment of nail psoriasis. Currently, there is a level B recommendation for the use of tazarotene for the treatment of nail psoriasis. Another effective regimen is combination therapy with vitamin D analogues and betamethasone dipropionate.⁹ Topical steroid use for nail psoriasis should be limited to 12 weeks because of the risk for bone atrophy with chronic steroid use.

Palmoplantar—The palms and soles have a thicker epidermal layer than other areas of the body. As a result, class 1 corticosteroids can be used for palmoplantar psoriasis for more than 4 weeks with vigilant monitoring for adverse effects such as skin atrophy, tachyphylaxis, or tinea infection. Tazarotene also has been shown to be helpful in treating palmoplantar psoriasis.

Resistant Disease—Intralesional steroids are beneficial treatment options for recalcitrant psoriasis in glabrous areas, as well as for palmoplantar, nail, and scalp psoriasis. Up to 10 mg/mL of triamcinolone acetonide used every 3 to 4 weeks is an effective regimen.¹⁰Pregnancy/Breastfeeding—Women of childbearing potential have additional safety precautions that should be considered during medication selection. Emollients have been shown to be safe during pregnancy and lactation. Currently, there is little known about CNI use during pregnancy. During lactation, CNIs can be used by breastfeeding mothers in most areas, excluding the breasts. Evaluation of the safety of anthralin and vitamin D analogues during pregnancy and lactation have not been studied. For these agents, dermatologists need to use their clinical judgment to weigh the risks and benefits of medication, particularly in patients requiring occlusion, higher medication doses, or treatment over a large surface area. Salicylic acid should be used with caution in pregnant and breastfeeding mothers because it is a pregnancy category C drug. Lower-potency corticosteroids may be used with caution during pregnancy and breastfeeding. More potent corticosteroids and coal tar, however, should be avoided. Similarly, tazarotene use is contraindicated in pregnancy. According to the US Food and Drug Administration labels for all forms of topical tazarotene, a pregnancy test must be obtained 2 weeks prior to tazarotene treatment initiation in women of childbearing potential because of the risk for serious fetal malformations and toxicity.

Recommendations, Risks, and Benefits of Topical Therapy for the Management of Psoriasis

Topical Corticosteroids—Topical corticosteroids (TCs) are widely used for inflammatory skin conditions and are available in a variety of strengths (Table 2). They are thought to exert their action by regulating the gene transcription of proinflammatory mediators. For psoriasis, steroids are recommended for 2 to 4 weeks, depending on disease severity. Although potent and superpotent steroids are more effective than mild- to moderate-strength TCs, use of lower-potency TCs may be warranted depending on disease distribution and localization.¹¹ For treatment of psoriasis with no involvement of the intertriginous areas, use of class 1 to 5 TCs for up to 4 weeks is recommended.

For moderate to severe psoriasis with 20% or less body surface area (BSA) affected, combination therapy consisting of mometasone and salicylic acid has been shown to be more effective than mometasone alone.^12,13 There currently is a level A recommendation for the use of combination therapy with class 1 TCs and etanercept for 12 weeks in patients with moderate to severe psoriasis who require both systemic and topical therapies for disease control. Similarly, combination therapy with infliximab and high-potency TCs has a level B recommendation to enhance efficacy for the treatment of moderate to severe psoriasis.¹⁴ High-quality studies on the use of TCs with anti–IL-12/IL-23, anti–IL-23, and anti–IL-17 currently are unavailable, but the combination is not expected to be unsafe.^14,15 Combination therapy of betamethasone dipropionate ointment and low-dose cyclosporine is an alternative regimen with a level B recommendation.

The most common adverse effects with use of TCs are skin thinning and atrophy, telangiectasia, and striae (Table 1). With clinical improvement of disease, it is recommended that clinicians taper TCs to prevent rebound effect. To decrease TC-related adverse effects, clinicians should use combination therapy with steroid-sparing agents for disease maintenance, transition to lower-potency corticosteroids, or use intermittent steroid therapy. Systemic effects of TC use include hypothalamic-pituitary-adrenal axis suppression, Cushing syndrome, and osteonecrosis of the femoral head.^16-18 These systemic effects with TC use are rare unless treatment is for disease involving greater than 20% BSA or occlusion for more than 4 weeks.

Calcineurin Inhibitors—Calcineurin inhibitors inhibit calcineurin phosphorylation and T-cell activation, subsequently decreasing the expression of proinflammatory cytokines. Currently, they are not approved by the US Food and Drug Administration to treat psoriasis but have demonstrated efficacy in randomized control trials (RCTs) for facial and intertriginous psoriasis. In RCTs, 71% of patients using pimecrolimus cream 0.1% twice daily for 8 weeks achieved an investigator global assessment score of clear (0) or almost clear (1) compared with 21% of placebo-treated patients (N=57).¹⁹ Other trials have shown that 65% of patients receiving tacrolimus ointment 0.1% for 8 weeks achieved an investigator global assessment score of 0 or 1 compared with 31% of placebo-treated patients (N=167).²⁰ Because of their efficacy in RCTs, CNIs commonly are used off label to treat psoriasis.

The most common adverse effects with CNI use are burning, pruritus, and flushing with alcohol ingestion (Table 1). Additionally, CNIs have a black box warning that use may increase the risk for malignancy, but this risk has not been demonstrated with topical use in humans.²¹Vitamin D Analogues—The class of vitamin D analogues—calcipotriol/calcipotriene and calcitriol—frequently are used to treat psoriasis. Vitamin D analogues exert their beneficial effects by inhibiting keratinocyte proliferation and enhancing keratinocyte differentiation. They also are ideal for long-term use (up to 52 weeks) in mild to moderate psoriasis and can be used in combination with class 2 and 3 TCs. There is a level A recommendation that supports the use of combination therapy with calcipotriol and TCs for the treatment of mild to moderate psoriasis.

For severe psoriasis, many studies have investigated the efficacy of combination therapy with vitamin D analogues and systemic treatments. Combination therapy with calcipotriol and methotrexate or calcipotriol and acitretin are effective treatment regimens with level A recommendations. Calcipotriol–betamethasone dipropionate ointment in combination with low-dose cyclosporine is an alternative option with a level B recommendation. Because vitamin D analogues are inactivated by UVA and UVB radiation, clinicians should advise their patients to use vitamin D analogues after receiving UVB phototherapy.²²

Common adverse effects of vitamin D analogues include burning, pruritus, erythema, and dryness (Table 1). Hypercalcemia and parathyroid hormone suppression are extremely rare unless treatment occurs over a large surface area (>30% BSA) or the patient has concurrent renal disease or impairments in calcium metabolism.

Tazarotene—Tazarotene is a topical retinoid that acts by decreasing keratinocyte proliferation, facilitating keratinocyte differentiation, and inhibiting inflammation. Patients with mild to moderate psoriasis are recommended to receive tazarotene treatment for 8 to 12 weeks. In several RCTs, tazarotene gel 0.1% and tazarotene cream 0.1% and 0.05% achieved treatment success in treating plaque psoriasis.^23,24

For increased efficacy, clinicians can recommend combination therapy with tazarotene and a TC. Combination therapy with tazarotene and a mid- or high-potency TC for 8 to 16 weeks has been shown to be more effective than treatment with tazarotene alone.²⁵ Thus, there is a level A recommendation for use of this combination to treat mild to moderate psoriasis. Agents used in combination therapy work synergistically to decrease the length of treatment and increase the duration of remission. The frequency of adverse effects, such as irritation from tazarotene and skin atrophy from TCs, also are reduced.²⁶ Combination therapy with tazarotene and narrowband UVB (NB-UVB) is another effective option that requires less UV radiation than NB-UVB alone because of the synergistic effects of both treatment modalities.²⁷ Clinicians should counsel patients on the adverse effects of tazarotene, which include local irritation, burning, pruritus, and erythema (Table 1).

Emollients—Emollients are nonmedicated moisturizers that decrease the amount of transepidermal water loss. There is a level B recommendation for use of emollients and TCs in combination for 4 to 8 weeks to treat psoriasis. In fact, combination therapy with mometasone and emollients has demonstrated greater improvement in symptoms of palmoplantar psoriasis (ie, erythema, desquamation, infiltration, BSA involvement) than mometasone alone.²⁸ Emollients are safe options that can be used on all areas of the body and during pregnancy and lactation. Although adverse effects of emollients are rare, clinicians should counsel patients on the risk for contact dermatitis if specific allergies to ingredients/fragrances exist (Table 1).

Salicylic Acid—Salicylic acid is a topical keratolytic that can be used to treat psoriatic plaques. Use of salicylic acid for 8 to 16 weeks has been shown to be effective for mild to moderate psoriasis. Combination therapy of salicylic acid and TCs in patients with 20% or less BSA affected is a safe and effective option with a level B recommendation. Combination therapy with salicylic acid and calcipotriene, however, should be avoided because calcipotriene is inactivated by salicylic acid. It also is recommended that salicylic acid application follow phototherapy when both treatment modalities are used in combination.^29,30 Clinicians should be cautious about using salicylic acid in patients with renal or hepatic disease because of the increased risk for salicylate toxicity (Table 1).

Anthralin—Anthralin is a synthetic hydrocarbon derivative that has been shown to reduce inflammation and normalize keratinocyte proliferation through an unknown mechanism. It is recommended that patients with mild to moderate psoriasis receive anthralin treatment for 8 to 12 weeks, with a maximum application time of 2 hours per day. Combination therapy of excimer laser and anthralin has been shown to be more effective in treating psoriasis than anthralin alone.³¹ Therefore, clinicians have the option of including excimer laser therapy for additional disease control. Anthralin should be avoided on the face, flexural regions, and highly visible areas because of potential skin staining (Table 1). Other adverse effects include application-site burning and erythema.

Coal Tar—Coal tar is a heterogenous mixture of aromatic hydrocarbons that is an effective treatment of psoriasis because of its inherent anti-inflammatory and keratoplastic properties. There is high-quality evidence supporting a level A recommendation for coal tar use in mild to moderate psoriasis. Combination therapy with NB-UVB and coal tar (also known as Goeckerman therapy) is a recommended treatment option with a quicker onset of action and improved outcomes compared with NB-UVB therapy alone.^32,33 Adverse events of coal tar include application-site irritation, folliculitis, contact dermatitis, phototoxicity, and skin pigmentation (Table 1).

Conclusion

Topical medications are versatile treatment options that can be utilized as monotherapy or adjunct therapy for mild to severe psoriasis. Benefits of topical agents include minimal required monitoring, few contraindications, and direct localized effect on plaques. Therefore, side effects with topical agent use rarely are systemic. Medication interactions are less of a concern with topical therapies; thus, they have better safety profiles compared with systemic therapies. This clinical review summarizes the recently published evidence-based guidelines from the AAD and NPF on the use of topical agents in psoriasis and may be a useful guiding framework for clinicians in their everyday practice.

Psoriasis is a chronic inflammatory skin disease characterized by erythematous scaly plaques that can invoke substantial pain, pruritus, and quality-of-life disturbance in patients. Topical therapies are the most commonly used medications for treating psoriasis, with one study (N = 128,308) showing that more than 85% of patients with psoriasis were managed solely with topical medications. ¹ For patients with mild to moderate psoriasis, topical agents alone may be able to control disease completely. For those with more severe disease, topical agents are used adjunctively with systemic or biologic agents to optimize disease control in localized areas.

The American Academy of Dermatology (AAD) and National Psoriasis Foundation (NPF) published guidelines in 2020 for managing psoriasis with topical agents in adults.² This review presents the most up-to-date clinical recommendations for topical agent use in adult patients with psoriasis and elaborates on each drug’s pharmacologic and safety profile. Specifically, evidence-based treatment recommendations for topical steroids, calcineurin inhibitors (CNIs), vitamin D analogues, retinoids (tazarotene), emollients, keratolytics (salicylic acid), anthracenes (anthralin), and keratoplastics (coal tar) will be addressed (Table 1). Recommendations for combination therapy with other treatment modalities including UVB light therapy, biologics, and systemic nonbiologic agents also will be discussed.

Selecting a Topical Agent Based on Disease Localization

When treating patients with psoriasis with topical therapies, clinicians should take into consideration drug potency, as it determines how effective a treatment will be in penetrating the skin barrier. Plaque characteristics, such as distribution (localized vs widespread), anatomical localization (flexural, scalp, palms/soles/nails), size (large vs small), and thickness (thick vs thin), not only influence treatment effectiveness but also the incidence of drug-related adverse events. Furthermore, preferred topical therapies are tailored to each patient based on disease characteristics and activity. Coal tar and anthralin have been used less frequently than other topical therapies for psoriasis because of their undesirable side-effect profiles (Table 1).³

Face and Intertriginous Regions—The face and intertriginous areas are sensitive because skin tends to be thin in these regions. Emollients are recommended for disease in these locations given their safety and flexibility in use for most areas. Conversely, anthralin should be avoided on the face, intertriginous areas, and even highly visible locations because of the potential for skin staining. Low-potency corticosteroids also have utility in psoriasis distributed on the face and intertriginous regions. Additionally, application of steroids around the eyes should be cautioned because topical steroids can induce ocular complications such as glaucoma and cataracts in rare circumstances.⁴

Off-label use of CNIs for psoriasis on the face and intertriginous areas also is effective. Currently, there is a level B recommendation for off-label use of 0.1% tacrolimus for up to 8 weeks for inverse psoriasis or psoriasis on the face. Off-label use of pimecrolimus for 4 to 8 weeks also can be considered for inverse psoriasis. Combination therapy consisting of hydrocortisone with calcipotriol ointment is another effective regimen.⁵ One study also suggested that use of crisaborole for 4 to 8 weeks in intertriginous psoriasis can be effective and well tolerated.⁶

Scalp—The vehicle of medication administration is especially important in hair-bearing areas such as the scalp, as these areas are challenging for medication application and patient adherence. Thus, patient preferences for the vehicle must be considered. Several studies have been conducted to assess preference for various vehicles in scalp psoriasis. A foam or solution may be preferable to ointments, gels, or creams.⁷ Gels may be preferred over ointments.⁸ There is a level A recommendation supporting the use of class 1 to 7 topical steroids for a minimum of 4 weeks as initial and maintenance treatment of scalp psoriasis. The highest level of evidence (level A) also supports the use of calcipotriol foam or combination therapy of calcipotriol–betamethasone dipropionate gel for 4 to 12 weeks as treatment of mild to moderate scalp psoriasis.

Nails—Several options for topical medications have been recommended for the treatment of nail psoriasis. Currently, there is a level B recommendation for the use of tazarotene for the treatment of nail psoriasis. Another effective regimen is combination therapy with vitamin D analogues and betamethasone dipropionate.⁹ Topical steroid use for nail psoriasis should be limited to 12 weeks because of the risk for bone atrophy with chronic steroid use.

Palmoplantar—The palms and soles have a thicker epidermal layer than other areas of the body. As a result, class 1 corticosteroids can be used for palmoplantar psoriasis for more than 4 weeks with vigilant monitoring for adverse effects such as skin atrophy, tachyphylaxis, or tinea infection. Tazarotene also has been shown to be helpful in treating palmoplantar psoriasis.

Resistant Disease—Intralesional steroids are beneficial treatment options for recalcitrant psoriasis in glabrous areas, as well as for palmoplantar, nail, and scalp psoriasis. Up to 10 mg/mL of triamcinolone acetonide used every 3 to 4 weeks is an effective regimen.¹⁰Pregnancy/Breastfeeding—Women of childbearing potential have additional safety precautions that should be considered during medication selection. Emollients have been shown to be safe during pregnancy and lactation. Currently, there is little known about CNI use during pregnancy. During lactation, CNIs can be used by breastfeeding mothers in most areas, excluding the breasts. Evaluation of the safety of anthralin and vitamin D analogues during pregnancy and lactation have not been studied. For these agents, dermatologists need to use their clinical judgment to weigh the risks and benefits of medication, particularly in patients requiring occlusion, higher medication doses, or treatment over a large surface area. Salicylic acid should be used with caution in pregnant and breastfeeding mothers because it is a pregnancy category C drug. Lower-potency corticosteroids may be used with caution during pregnancy and breastfeeding. More potent corticosteroids and coal tar, however, should be avoided. Similarly, tazarotene use is contraindicated in pregnancy. According to the US Food and Drug Administration labels for all forms of topical tazarotene, a pregnancy test must be obtained 2 weeks prior to tazarotene treatment initiation in women of childbearing potential because of the risk for serious fetal malformations and toxicity.

Recommendations, Risks, and Benefits of Topical Therapy for the Management of Psoriasis

Topical Corticosteroids—Topical corticosteroids (TCs) are widely used for inflammatory skin conditions and are available in a variety of strengths (Table 2). They are thought to exert their action by regulating the gene transcription of proinflammatory mediators. For psoriasis, steroids are recommended for 2 to 4 weeks, depending on disease severity. Although potent and superpotent steroids are more effective than mild- to moderate-strength TCs, use of lower-potency TCs may be warranted depending on disease distribution and localization.¹¹ For treatment of psoriasis with no involvement of the intertriginous areas, use of class 1 to 5 TCs for up to 4 weeks is recommended.

For moderate to severe psoriasis with 20% or less body surface area (BSA) affected, combination therapy consisting of mometasone and salicylic acid has been shown to be more effective than mometasone alone.^12,13 There currently is a level A recommendation for the use of combination therapy with class 1 TCs and etanercept for 12 weeks in patients with moderate to severe psoriasis who require both systemic and topical therapies for disease control. Similarly, combination therapy with infliximab and high-potency TCs has a level B recommendation to enhance efficacy for the treatment of moderate to severe psoriasis.¹⁴ High-quality studies on the use of TCs with anti–IL-12/IL-23, anti–IL-23, and anti–IL-17 currently are unavailable, but the combination is not expected to be unsafe.^14,15 Combination therapy of betamethasone dipropionate ointment and low-dose cyclosporine is an alternative regimen with a level B recommendation.

The most common adverse effects with use of TCs are skin thinning and atrophy, telangiectasia, and striae (Table 1). With clinical improvement of disease, it is recommended that clinicians taper TCs to prevent rebound effect. To decrease TC-related adverse effects, clinicians should use combination therapy with steroid-sparing agents for disease maintenance, transition to lower-potency corticosteroids, or use intermittent steroid therapy. Systemic effects of TC use include hypothalamic-pituitary-adrenal axis suppression, Cushing syndrome, and osteonecrosis of the femoral head.^16-18 These systemic effects with TC use are rare unless treatment is for disease involving greater than 20% BSA or occlusion for more than 4 weeks.

Calcineurin Inhibitors—Calcineurin inhibitors inhibit calcineurin phosphorylation and T-cell activation, subsequently decreasing the expression of proinflammatory cytokines. Currently, they are not approved by the US Food and Drug Administration to treat psoriasis but have demonstrated efficacy in randomized control trials (RCTs) for facial and intertriginous psoriasis. In RCTs, 71% of patients using pimecrolimus cream 0.1% twice daily for 8 weeks achieved an investigator global assessment score of clear (0) or almost clear (1) compared with 21% of placebo-treated patients (N=57).¹⁹ Other trials have shown that 65% of patients receiving tacrolimus ointment 0.1% for 8 weeks achieved an investigator global assessment score of 0 or 1 compared with 31% of placebo-treated patients (N=167).²⁰ Because of their efficacy in RCTs, CNIs commonly are used off label to treat psoriasis.

The most common adverse effects with CNI use are burning, pruritus, and flushing with alcohol ingestion (Table 1). Additionally, CNIs have a black box warning that use may increase the risk for malignancy, but this risk has not been demonstrated with topical use in humans.²¹Vitamin D Analogues—The class of vitamin D analogues—calcipotriol/calcipotriene and calcitriol—frequently are used to treat psoriasis. Vitamin D analogues exert their beneficial effects by inhibiting keratinocyte proliferation and enhancing keratinocyte differentiation. They also are ideal for long-term use (up to 52 weeks) in mild to moderate psoriasis and can be used in combination with class 2 and 3 TCs. There is a level A recommendation that supports the use of combination therapy with calcipotriol and TCs for the treatment of mild to moderate psoriasis.

For severe psoriasis, many studies have investigated the efficacy of combination therapy with vitamin D analogues and systemic treatments. Combination therapy with calcipotriol and methotrexate or calcipotriol and acitretin are effective treatment regimens with level A recommendations. Calcipotriol–betamethasone dipropionate ointment in combination with low-dose cyclosporine is an alternative option with a level B recommendation. Because vitamin D analogues are inactivated by UVA and UVB radiation, clinicians should advise their patients to use vitamin D analogues after receiving UVB phototherapy.²²

Common adverse effects of vitamin D analogues include burning, pruritus, erythema, and dryness (Table 1). Hypercalcemia and parathyroid hormone suppression are extremely rare unless treatment occurs over a large surface area (>30% BSA) or the patient has concurrent renal disease or impairments in calcium metabolism.

Tazarotene—Tazarotene is a topical retinoid that acts by decreasing keratinocyte proliferation, facilitating keratinocyte differentiation, and inhibiting inflammation. Patients with mild to moderate psoriasis are recommended to receive tazarotene treatment for 8 to 12 weeks. In several RCTs, tazarotene gel 0.1% and tazarotene cream 0.1% and 0.05% achieved treatment success in treating plaque psoriasis.^23,24

For increased efficacy, clinicians can recommend combination therapy with tazarotene and a TC. Combination therapy with tazarotene and a mid- or high-potency TC for 8 to 16 weeks has been shown to be more effective than treatment with tazarotene alone.²⁵ Thus, there is a level A recommendation for use of this combination to treat mild to moderate psoriasis. Agents used in combination therapy work synergistically to decrease the length of treatment and increase the duration of remission. The frequency of adverse effects, such as irritation from tazarotene and skin atrophy from TCs, also are reduced.²⁶ Combination therapy with tazarotene and narrowband UVB (NB-UVB) is another effective option that requires less UV radiation than NB-UVB alone because of the synergistic effects of both treatment modalities.²⁷ Clinicians should counsel patients on the adverse effects of tazarotene, which include local irritation, burning, pruritus, and erythema (Table 1).

Emollients—Emollients are nonmedicated moisturizers that decrease the amount of transepidermal water loss. There is a level B recommendation for use of emollients and TCs in combination for 4 to 8 weeks to treat psoriasis. In fact, combination therapy with mometasone and emollients has demonstrated greater improvement in symptoms of palmoplantar psoriasis (ie, erythema, desquamation, infiltration, BSA involvement) than mometasone alone.²⁸ Emollients are safe options that can be used on all areas of the body and during pregnancy and lactation. Although adverse effects of emollients are rare, clinicians should counsel patients on the risk for contact dermatitis if specific allergies to ingredients/fragrances exist (Table 1).

Salicylic Acid—Salicylic acid is a topical keratolytic that can be used to treat psoriatic plaques. Use of salicylic acid for 8 to 16 weeks has been shown to be effective for mild to moderate psoriasis. Combination therapy of salicylic acid and TCs in patients with 20% or less BSA affected is a safe and effective option with a level B recommendation. Combination therapy with salicylic acid and calcipotriene, however, should be avoided because calcipotriene is inactivated by salicylic acid. It also is recommended that salicylic acid application follow phototherapy when both treatment modalities are used in combination.^29,30 Clinicians should be cautious about using salicylic acid in patients with renal or hepatic disease because of the increased risk for salicylate toxicity (Table 1).

Anthralin—Anthralin is a synthetic hydrocarbon derivative that has been shown to reduce inflammation and normalize keratinocyte proliferation through an unknown mechanism. It is recommended that patients with mild to moderate psoriasis receive anthralin treatment for 8 to 12 weeks, with a maximum application time of 2 hours per day. Combination therapy of excimer laser and anthralin has been shown to be more effective in treating psoriasis than anthralin alone.³¹ Therefore, clinicians have the option of including excimer laser therapy for additional disease control. Anthralin should be avoided on the face, flexural regions, and highly visible areas because of potential skin staining (Table 1). Other adverse effects include application-site burning and erythema.

Coal Tar—Coal tar is a heterogenous mixture of aromatic hydrocarbons that is an effective treatment of psoriasis because of its inherent anti-inflammatory and keratoplastic properties. There is high-quality evidence supporting a level A recommendation for coal tar use in mild to moderate psoriasis. Combination therapy with NB-UVB and coal tar (also known as Goeckerman therapy) is a recommended treatment option with a quicker onset of action and improved outcomes compared with NB-UVB therapy alone.^32,33 Adverse events of coal tar include application-site irritation, folliculitis, contact dermatitis, phototoxicity, and skin pigmentation (Table 1).

Conclusion

Topical medications are versatile treatment options that can be utilized as monotherapy or adjunct therapy for mild to severe psoriasis. Benefits of topical agents include minimal required monitoring, few contraindications, and direct localized effect on plaques. Therefore, side effects with topical agent use rarely are systemic. Medication interactions are less of a concern with topical therapies; thus, they have better safety profiles compared with systemic therapies. This clinical review summarizes the recently published evidence-based guidelines from the AAD and NPF on the use of topical agents in psoriasis and may be a useful guiding framework for clinicians in their everyday practice.

Psoriasis is a chronic inflammatory skin disease characterized by erythematous scaly plaques that can invoke substantial pain, pruritus, and quality-of-life disturbance in patients. Topical therapies are the most commonly used medications for treating psoriasis, with one study (N = 128,308) showing that more than 85% of patients with psoriasis were managed solely with topical medications. ¹ For patients with mild to moderate psoriasis, topical agents alone may be able to control disease completely. For those with more severe disease, topical agents are used adjunctively with systemic or biologic agents to optimize disease control in localized areas.

The American Academy of Dermatology (AAD) and National Psoriasis Foundation (NPF) published guidelines in 2020 for managing psoriasis with topical agents in adults.² This review presents the most up-to-date clinical recommendations for topical agent use in adult patients with psoriasis and elaborates on each drug’s pharmacologic and safety profile. Specifically, evidence-based treatment recommendations for topical steroids, calcineurin inhibitors (CNIs), vitamin D analogues, retinoids (tazarotene), emollients, keratolytics (salicylic acid), anthracenes (anthralin), and keratoplastics (coal tar) will be addressed (Table 1). Recommendations for combination therapy with other treatment modalities including UVB light therapy, biologics, and systemic nonbiologic agents also will be discussed.

Selecting a Topical Agent Based on Disease Localization

When treating patients with psoriasis with topical therapies, clinicians should take into consideration drug potency, as it determines how effective a treatment will be in penetrating the skin barrier. Plaque characteristics, such as distribution (localized vs widespread), anatomical localization (flexural, scalp, palms/soles/nails), size (large vs small), and thickness (thick vs thin), not only influence treatment effectiveness but also the incidence of drug-related adverse events. Furthermore, preferred topical therapies are tailored to each patient based on disease characteristics and activity. Coal tar and anthralin have been used less frequently than other topical therapies for psoriasis because of their undesirable side-effect profiles (Table 1).³

Face and Intertriginous Regions—The face and intertriginous areas are sensitive because skin tends to be thin in these regions. Emollients are recommended for disease in these locations given their safety and flexibility in use for most areas. Conversely, anthralin should be avoided on the face, intertriginous areas, and even highly visible locations because of the potential for skin staining. Low-potency corticosteroids also have utility in psoriasis distributed on the face and intertriginous regions. Additionally, application of steroids around the eyes should be cautioned because topical steroids can induce ocular complications such as glaucoma and cataracts in rare circumstances.⁴

Off-label use of CNIs for psoriasis on the face and intertriginous areas also is effective. Currently, there is a level B recommendation for off-label use of 0.1% tacrolimus for up to 8 weeks for inverse psoriasis or psoriasis on the face. Off-label use of pimecrolimus for 4 to 8 weeks also can be considered for inverse psoriasis. Combination therapy consisting of hydrocortisone with calcipotriol ointment is another effective regimen.⁵ One study also suggested that use of crisaborole for 4 to 8 weeks in intertriginous psoriasis can be effective and well tolerated.⁶

Scalp—The vehicle of medication administration is especially important in hair-bearing areas such as the scalp, as these areas are challenging for medication application and patient adherence. Thus, patient preferences for the vehicle must be considered. Several studies have been conducted to assess preference for various vehicles in scalp psoriasis. A foam or solution may be preferable to ointments, gels, or creams.⁷ Gels may be preferred over ointments.⁸ There is a level A recommendation supporting the use of class 1 to 7 topical steroids for a minimum of 4 weeks as initial and maintenance treatment of scalp psoriasis. The highest level of evidence (level A) also supports the use of calcipotriol foam or combination therapy of calcipotriol–betamethasone dipropionate gel for 4 to 12 weeks as treatment of mild to moderate scalp psoriasis.

Nails—Several options for topical medications have been recommended for the treatment of nail psoriasis. Currently, there is a level B recommendation for the use of tazarotene for the treatment of nail psoriasis. Another effective regimen is combination therapy with vitamin D analogues and betamethasone dipropionate.⁹ Topical steroid use for nail psoriasis should be limited to 12 weeks because of the risk for bone atrophy with chronic steroid use.

Palmoplantar—The palms and soles have a thicker epidermal layer than other areas of the body. As a result, class 1 corticosteroids can be used for palmoplantar psoriasis for more than 4 weeks with vigilant monitoring for adverse effects such as skin atrophy, tachyphylaxis, or tinea infection. Tazarotene also has been shown to be helpful in treating palmoplantar psoriasis.

Resistant Disease—Intralesional steroids are beneficial treatment options for recalcitrant psoriasis in glabrous areas, as well as for palmoplantar, nail, and scalp psoriasis. Up to 10 mg/mL of triamcinolone acetonide used every 3 to 4 weeks is an effective regimen.¹⁰Pregnancy/Breastfeeding—Women of childbearing potential have additional safety precautions that should be considered during medication selection. Emollients have been shown to be safe during pregnancy and lactation. Currently, there is little known about CNI use during pregnancy. During lactation, CNIs can be used by breastfeeding mothers in most areas, excluding the breasts. Evaluation of the safety of anthralin and vitamin D analogues during pregnancy and lactation have not been studied. For these agents, dermatologists need to use their clinical judgment to weigh the risks and benefits of medication, particularly in patients requiring occlusion, higher medication doses, or treatment over a large surface area. Salicylic acid should be used with caution in pregnant and breastfeeding mothers because it is a pregnancy category C drug. Lower-potency corticosteroids may be used with caution during pregnancy and breastfeeding. More potent corticosteroids and coal tar, however, should be avoided. Similarly, tazarotene use is contraindicated in pregnancy. According to the US Food and Drug Administration labels for all forms of topical tazarotene, a pregnancy test must be obtained 2 weeks prior to tazarotene treatment initiation in women of childbearing potential because of the risk for serious fetal malformations and toxicity.

Recommendations, Risks, and Benefits of Topical Therapy for the Management of Psoriasis

Topical Corticosteroids—Topical corticosteroids (TCs) are widely used for inflammatory skin conditions and are available in a variety of strengths (Table 2). They are thought to exert their action by regulating the gene transcription of proinflammatory mediators. For psoriasis, steroids are recommended for 2 to 4 weeks, depending on disease severity. Although potent and superpotent steroids are more effective than mild- to moderate-strength TCs, use of lower-potency TCs may be warranted depending on disease distribution and localization.¹¹ For treatment of psoriasis with no involvement of the intertriginous areas, use of class 1 to 5 TCs for up to 4 weeks is recommended.

For moderate to severe psoriasis with 20% or less body surface area (BSA) affected, combination therapy consisting of mometasone and salicylic acid has been shown to be more effective than mometasone alone.^12,13 There currently is a level A recommendation for the use of combination therapy with class 1 TCs and etanercept for 12 weeks in patients with moderate to severe psoriasis who require both systemic and topical therapies for disease control. Similarly, combination therapy with infliximab and high-potency TCs has a level B recommendation to enhance efficacy for the treatment of moderate to severe psoriasis.¹⁴ High-quality studies on the use of TCs with anti–IL-12/IL-23, anti–IL-23, and anti–IL-17 currently are unavailable, but the combination is not expected to be unsafe.^14,15 Combination therapy of betamethasone dipropionate ointment and low-dose cyclosporine is an alternative regimen with a level B recommendation.

The most common adverse effects with use of TCs are skin thinning and atrophy, telangiectasia, and striae (Table 1). With clinical improvement of disease, it is recommended that clinicians taper TCs to prevent rebound effect. To decrease TC-related adverse effects, clinicians should use combination therapy with steroid-sparing agents for disease maintenance, transition to lower-potency corticosteroids, or use intermittent steroid therapy. Systemic effects of TC use include hypothalamic-pituitary-adrenal axis suppression, Cushing syndrome, and osteonecrosis of the femoral head.^16-18 These systemic effects with TC use are rare unless treatment is for disease involving greater than 20% BSA or occlusion for more than 4 weeks.

Calcineurin Inhibitors—Calcineurin inhibitors inhibit calcineurin phosphorylation and T-cell activation, subsequently decreasing the expression of proinflammatory cytokines. Currently, they are not approved by the US Food and Drug Administration to treat psoriasis but have demonstrated efficacy in randomized control trials (RCTs) for facial and intertriginous psoriasis. In RCTs, 71% of patients using pimecrolimus cream 0.1% twice daily for 8 weeks achieved an investigator global assessment score of clear (0) or almost clear (1) compared with 21% of placebo-treated patients (N=57).¹⁹ Other trials have shown that 65% of patients receiving tacrolimus ointment 0.1% for 8 weeks achieved an investigator global assessment score of 0 or 1 compared with 31% of placebo-treated patients (N=167).²⁰ Because of their efficacy in RCTs, CNIs commonly are used off label to treat psoriasis.

The most common adverse effects with CNI use are burning, pruritus, and flushing with alcohol ingestion (Table 1). Additionally, CNIs have a black box warning that use may increase the risk for malignancy, but this risk has not been demonstrated with topical use in humans.²¹Vitamin D Analogues—The class of vitamin D analogues—calcipotriol/calcipotriene and calcitriol—frequently are used to treat psoriasis. Vitamin D analogues exert their beneficial effects by inhibiting keratinocyte proliferation and enhancing keratinocyte differentiation. They also are ideal for long-term use (up to 52 weeks) in mild to moderate psoriasis and can be used in combination with class 2 and 3 TCs. There is a level A recommendation that supports the use of combination therapy with calcipotriol and TCs for the treatment of mild to moderate psoriasis.

For severe psoriasis, many studies have investigated the efficacy of combination therapy with vitamin D analogues and systemic treatments. Combination therapy with calcipotriol and methotrexate or calcipotriol and acitretin are effective treatment regimens with level A recommendations. Calcipotriol–betamethasone dipropionate ointment in combination with low-dose cyclosporine is an alternative option with a level B recommendation. Because vitamin D analogues are inactivated by UVA and UVB radiation, clinicians should advise their patients to use vitamin D analogues after receiving UVB phototherapy.²²

Common adverse effects of vitamin D analogues include burning, pruritus, erythema, and dryness (Table 1). Hypercalcemia and parathyroid hormone suppression are extremely rare unless treatment occurs over a large surface area (>30% BSA) or the patient has concurrent renal disease or impairments in calcium metabolism.

Tazarotene—Tazarotene is a topical retinoid that acts by decreasing keratinocyte proliferation, facilitating keratinocyte differentiation, and inhibiting inflammation. Patients with mild to moderate psoriasis are recommended to receive tazarotene treatment for 8 to 12 weeks. In several RCTs, tazarotene gel 0.1% and tazarotene cream 0.1% and 0.05% achieved treatment success in treating plaque psoriasis.^23,24

For increased efficacy, clinicians can recommend combination therapy with tazarotene and a TC. Combination therapy with tazarotene and a mid- or high-potency TC for 8 to 16 weeks has been shown to be more effective than treatment with tazarotene alone.²⁵ Thus, there is a level A recommendation for use of this combination to treat mild to moderate psoriasis. Agents used in combination therapy work synergistically to decrease the length of treatment and increase the duration of remission. The frequency of adverse effects, such as irritation from tazarotene and skin atrophy from TCs, also are reduced.²⁶ Combination therapy with tazarotene and narrowband UVB (NB-UVB) is another effective option that requires less UV radiation than NB-UVB alone because of the synergistic effects of both treatment modalities.²⁷ Clinicians should counsel patients on the adverse effects of tazarotene, which include local irritation, burning, pruritus, and erythema (Table 1).

Emollients—Emollients are nonmedicated moisturizers that decrease the amount of transepidermal water loss. There is a level B recommendation for use of emollients and TCs in combination for 4 to 8 weeks to treat psoriasis. In fact, combination therapy with mometasone and emollients has demonstrated greater improvement in symptoms of palmoplantar psoriasis (ie, erythema, desquamation, infiltration, BSA involvement) than mometasone alone.²⁸ Emollients are safe options that can be used on all areas of the body and during pregnancy and lactation. Although adverse effects of emollients are rare, clinicians should counsel patients on the risk for contact dermatitis if specific allergies to ingredients/fragrances exist (Table 1).

Salicylic Acid—Salicylic acid is a topical keratolytic that can be used to treat psoriatic plaques. Use of salicylic acid for 8 to 16 weeks has been shown to be effective for mild to moderate psoriasis. Combination therapy of salicylic acid and TCs in patients with 20% or less BSA affected is a safe and effective option with a level B recommendation. Combination therapy with salicylic acid and calcipotriene, however, should be avoided because calcipotriene is inactivated by salicylic acid. It also is recommended that salicylic acid application follow phototherapy when both treatment modalities are used in combination.^29,30 Clinicians should be cautious about using salicylic acid in patients with renal or hepatic disease because of the increased risk for salicylate toxicity (Table 1).

Anthralin—Anthralin is a synthetic hydrocarbon derivative that has been shown to reduce inflammation and normalize keratinocyte proliferation through an unknown mechanism. It is recommended that patients with mild to moderate psoriasis receive anthralin treatment for 8 to 12 weeks, with a maximum application time of 2 hours per day. Combination therapy of excimer laser and anthralin has been shown to be more effective in treating psoriasis than anthralin alone.³¹ Therefore, clinicians have the option of including excimer laser therapy for additional disease control. Anthralin should be avoided on the face, flexural regions, and highly visible areas because of potential skin staining (Table 1). Other adverse effects include application-site burning and erythema.

Coal Tar—Coal tar is a heterogenous mixture of aromatic hydrocarbons that is an effective treatment of psoriasis because of its inherent anti-inflammatory and keratoplastic properties. There is high-quality evidence supporting a level A recommendation for coal tar use in mild to moderate psoriasis. Combination therapy with NB-UVB and coal tar (also known as Goeckerman therapy) is a recommended treatment option with a quicker onset of action and improved outcomes compared with NB-UVB therapy alone.^32,33 Adverse events of coal tar include application-site irritation, folliculitis, contact dermatitis, phototoxicity, and skin pigmentation (Table 1).

Conclusion

Topical medications are versatile treatment options that can be utilized as monotherapy or adjunct therapy for mild to severe psoriasis. Benefits of topical agents include minimal required monitoring, few contraindications, and direct localized effect on plaques. Therefore, side effects with topical agent use rarely are systemic. Medication interactions are less of a concern with topical therapies; thus, they have better safety profiles compared with systemic therapies. This clinical review summarizes the recently published evidence-based guidelines from the AAD and NPF on the use of topical agents in psoriasis and may be a useful guiding framework for clinicians in their everyday practice.