Cutis

The Diagnosis: Black-Spot Poison Ivy

Due to the detailed account of the patient's history including acuity of current presentation, history of recent activities, travel history, and recent exposures, as well as a thorough skin examination, a diagnosis of black-spot poison ivy was made. In this case, the linear distribution of the lesions with overlying black pigment that could not be removed (Figures 1 and 2) provided important clues to diagnosis.

Poison ivy is an allergic contact dermatitis that affects an estimated 25 to 40 million Americans annually who are exposed to its resin. Poison ivy is a plant from the Toxicodendron genus, and an estimated 85% of the North American population report sensitivity to these plants, of which poison ivy (Toxicodendron radicans) is the most common.¹ Other related plants include poison sumac and poison oak. Poison ivy and other Toxicodendron plants produce urushiol, the oleoresin responsible for one of the most common allergic contact dermatitides in the United States.² Black-spot poison ivy is an uncommon presentation following exposure to urushiol or oleoresin,³ as sufficient concentration of urushiol on the skin rarely is achieved.^3,4 This plant's resin oxidizes and turns coal black when exposed to air.⁵ Contact with enough of this oleoresin will produce black-spot poison ivy.⁶ Patients with sufficient concentrations of oleoresin on their skin to cause this black oxidation usually have similar black spots on their clothing.⁷ Interestingly, some Toxicodendron species, such as the Japanese lacquer tree, Toxicodendron vernicifluum, have a black lacquer sap that was historically used as ink.⁸ This ink was used on Chinese and Japanese jars and has caused contact dermatitis hundreds of years after they were created.⁷

Poison ivy is characterized by a generalized, pruritic, erythematous rash with vesicles and papules in a linear distribution.⁹ Black-spot poison ivy presents the same with the addition of black lacquer-like macules with surrounding erythema.¹⁰ The skin lesions usually appear on exposed areas 24 to 48 hours after contact.¹¹ Histology of black-spot poison ivy lesions should reveal yellow material in the stratum corneum with epidermal necrosis, in addition to classic features of acute allergic contact dermatitis.³ Interestingly, because these lesions occur with the first exposure to poison ivy, a patient may not develop the typical itchy eczematous eruption characteristic of poison ivy dermatitis. Differential diagnosis includes superficial purpura; exogenous pigment such as marker, ink, or tattoo pigment; tinea nigra; purpuric allergic contact dermatitis to resins or dyes; arthropod assault; irritant contact dermatitis; and infectious and noninfectious vasculitis.¹¹

Similar to poison ivy, treatment of black-spot poison ivy involves oral and topical steroids combined with antihistamines if the patient continues to experience pruritus.^6,12 It was recommended to our patient to apply cool compresses with water or Burow solution to alleviate itching and promote drying of the lesions. Calamine lotion can provide similar outcomes.¹³ Once the oleoresin is oxidized and bound to skin, the black spots cannot be removed with soap, water, or alcohol. The black spots gradually desquamate 1 to 2 weeks after formation without scarring,¹¹ and patients do not require further monitoring.¹ Patients should clean or discard clothing and evaluate for possible sources of poison ivy exposure. Because this type of poison ivy dermatitis is rare, most health care workers likely have never seen black-spot poison ivy, and it is an important diagnosis to consider.¹³

The Diagnosis: Black-Spot Poison Ivy

Due to the detailed account of the patient's history including acuity of current presentation, history of recent activities, travel history, and recent exposures, as well as a thorough skin examination, a diagnosis of black-spot poison ivy was made. In this case, the linear distribution of the lesions with overlying black pigment that could not be removed (Figures 1 and 2) provided important clues to diagnosis.

Poison ivy is an allergic contact dermatitis that affects an estimated 25 to 40 million Americans annually who are exposed to its resin. Poison ivy is a plant from the Toxicodendron genus, and an estimated 85% of the North American population report sensitivity to these plants, of which poison ivy (Toxicodendron radicans) is the most common.¹ Other related plants include poison sumac and poison oak. Poison ivy and other Toxicodendron plants produce urushiol, the oleoresin responsible for one of the most common allergic contact dermatitides in the United States.² Black-spot poison ivy is an uncommon presentation following exposure to urushiol or oleoresin,³ as sufficient concentration of urushiol on the skin rarely is achieved.^3,4 This plant's resin oxidizes and turns coal black when exposed to air.⁵ Contact with enough of this oleoresin will produce black-spot poison ivy.⁶ Patients with sufficient concentrations of oleoresin on their skin to cause this black oxidation usually have similar black spots on their clothing.⁷ Interestingly, some Toxicodendron species, such as the Japanese lacquer tree, Toxicodendron vernicifluum, have a black lacquer sap that was historically used as ink.⁸ This ink was used on Chinese and Japanese jars and has caused contact dermatitis hundreds of years after they were created.⁷

Poison ivy is characterized by a generalized, pruritic, erythematous rash with vesicles and papules in a linear distribution.⁹ Black-spot poison ivy presents the same with the addition of black lacquer-like macules with surrounding erythema.¹⁰ The skin lesions usually appear on exposed areas 24 to 48 hours after contact.¹¹ Histology of black-spot poison ivy lesions should reveal yellow material in the stratum corneum with epidermal necrosis, in addition to classic features of acute allergic contact dermatitis.³ Interestingly, because these lesions occur with the first exposure to poison ivy, a patient may not develop the typical itchy eczematous eruption characteristic of poison ivy dermatitis. Differential diagnosis includes superficial purpura; exogenous pigment such as marker, ink, or tattoo pigment; tinea nigra; purpuric allergic contact dermatitis to resins or dyes; arthropod assault; irritant contact dermatitis; and infectious and noninfectious vasculitis.¹¹

Similar to poison ivy, treatment of black-spot poison ivy involves oral and topical steroids combined with antihistamines if the patient continues to experience pruritus.^6,12 It was recommended to our patient to apply cool compresses with water or Burow solution to alleviate itching and promote drying of the lesions. Calamine lotion can provide similar outcomes.¹³ Once the oleoresin is oxidized and bound to skin, the black spots cannot be removed with soap, water, or alcohol. The black spots gradually desquamate 1 to 2 weeks after formation without scarring,¹¹ and patients do not require further monitoring.¹ Patients should clean or discard clothing and evaluate for possible sources of poison ivy exposure. Because this type of poison ivy dermatitis is rare, most health care workers likely have never seen black-spot poison ivy, and it is an important diagnosis to consider.¹³

The Diagnosis: Black-Spot Poison Ivy

Due to the detailed account of the patient's history including acuity of current presentation, history of recent activities, travel history, and recent exposures, as well as a thorough skin examination, a diagnosis of black-spot poison ivy was made. In this case, the linear distribution of the lesions with overlying black pigment that could not be removed (Figures 1 and 2) provided important clues to diagnosis.

Poison ivy is an allergic contact dermatitis that affects an estimated 25 to 40 million Americans annually who are exposed to its resin. Poison ivy is a plant from the Toxicodendron genus, and an estimated 85% of the North American population report sensitivity to these plants, of which poison ivy (Toxicodendron radicans) is the most common.¹ Other related plants include poison sumac and poison oak. Poison ivy and other Toxicodendron plants produce urushiol, the oleoresin responsible for one of the most common allergic contact dermatitides in the United States.² Black-spot poison ivy is an uncommon presentation following exposure to urushiol or oleoresin,³ as sufficient concentration of urushiol on the skin rarely is achieved.^3,4 This plant's resin oxidizes and turns coal black when exposed to air.⁵ Contact with enough of this oleoresin will produce black-spot poison ivy.⁶ Patients with sufficient concentrations of oleoresin on their skin to cause this black oxidation usually have similar black spots on their clothing.⁷ Interestingly, some Toxicodendron species, such as the Japanese lacquer tree, Toxicodendron vernicifluum, have a black lacquer sap that was historically used as ink.⁸ This ink was used on Chinese and Japanese jars and has caused contact dermatitis hundreds of years after they were created.⁷

Poison ivy is characterized by a generalized, pruritic, erythematous rash with vesicles and papules in a linear distribution.⁹ Black-spot poison ivy presents the same with the addition of black lacquer-like macules with surrounding erythema.¹⁰ The skin lesions usually appear on exposed areas 24 to 48 hours after contact.¹¹ Histology of black-spot poison ivy lesions should reveal yellow material in the stratum corneum with epidermal necrosis, in addition to classic features of acute allergic contact dermatitis.³ Interestingly, because these lesions occur with the first exposure to poison ivy, a patient may not develop the typical itchy eczematous eruption characteristic of poison ivy dermatitis. Differential diagnosis includes superficial purpura; exogenous pigment such as marker, ink, or tattoo pigment; tinea nigra; purpuric allergic contact dermatitis to resins or dyes; arthropod assault; irritant contact dermatitis; and infectious and noninfectious vasculitis.¹¹

Similar to poison ivy, treatment of black-spot poison ivy involves oral and topical steroids combined with antihistamines if the patient continues to experience pruritus.^6,12 It was recommended to our patient to apply cool compresses with water or Burow solution to alleviate itching and promote drying of the lesions. Calamine lotion can provide similar outcomes.¹³ Once the oleoresin is oxidized and bound to skin, the black spots cannot be removed with soap, water, or alcohol. The black spots gradually desquamate 1 to 2 weeks after formation without scarring,¹¹ and patients do not require further monitoring.¹ Patients should clean or discard clothing and evaluate for possible sources of poison ivy exposure. Because this type of poison ivy dermatitis is rare, most health care workers likely have never seen black-spot poison ivy, and it is an important diagnosis to consider.¹³

The Diagnosis: Acute Generalized Exanthematous Pustulosis

Histopathology demonstrated spongiosis with subcorneal pustules and an overlying basket-weave pattern stratum corneum. There was mild papillary dermal edema with scattered dermal neutrophils and rare eosinophils (Figure). The patient's clinical presentation and histopathology were consistent with acute generalized exanthematous pustulosis (AGEP). The inciting agent in this case was the contrast medium iopamidol. The patient was treated with a short course of prednisone, triamcinolone cream, diphenhydramine, and acetaminophen. Within 1 week the pustules and erythema had resolved.

Acute generalized exanthematous pustulosis is an uncommon T cell-mediated cutaneous reaction characterized by widespread progressive erythema with numerous nonfollicular pinpoint pustules. The patient usually is well appearing; however, he/she often will have concurrent fever and facial edema. Mucous membranes rarely are involved. Laboratory results typically are notable only for leukocytosis with neutrophilia.

The pustular eruption typically occurs within 1 to 2 days after exposure to an inciting agent¹; however, this latent period can range from 1 hour to nearly 4 weeks in some studies.² Systemic medications are the cause in approximately 90% of cases, with antibiotics being the most common category. Frequently implicated medications include β-lactams, macrolides, quinolones, sulfonamides, proton pump inhibitors, hydroxychloroquine, terbinafine, nonsteroidal anti-inflammatory drugs, diltiazem, ketoconazole, and fluconazole. Acute generalized exanthematous pustulosis also has been rarely reported following contact with mercury, viral and bacterial infections, and spider bites.³

Iodinated contrast agents have long been known to cause immediate and delayed adverse cutaneous reactions. However, one consensus study indicated that these reactions occur in only 0.05% to 0.10% of patients.⁴ Although rare, iodinated contrast media (eg, iopamidol, iohexol, ioversol, iodixanol, iomeprol, iobitridol, iopromide) have been reported as a cause of AGEP. A PubMed search of articles indexed for MEDLINE using the terms acute generalized exanthematous pustulosis, contrast, iodine, and iodinated revealed 10 adult cases reported in 6 articles in the English-language literature.^1,5-9 The most recent articles focus on methods to identify the causative agent. If the etiology of the reaction is unclear, patch or intradermal testing can help to confirm the causative agent. These tests also can help determine similar agents to which the patient may cross-react.^4,5

It can be difficult to differentiate AGEP from other cutaneous drug reactions and other nonfollicular pustular conditions. Drug-induced hypersensitivity syndrome typically presents with facial edema and a morbilliform rash. Although it can present with pustules, the latent period is longer (2-6 weeks), and there frequently are signs of multiorgan involvement including hepatic dysfunction, eosinophilia, atypical lymphocytosis, and lymphadenopathy. Patients with generalized pustular psoriasis often have a history of plaque psoriasis; the pustules are more concentrated in flexural sites; the eruption is gradual in onset; and histologically there tends to be features of psoriasis including parakeratosis, Munro microabscesses, and dilated blood vessels.¹⁰ Subcorneal pustular dermatosis also is more concentrated in flexural sites and frequently has an annular or serpiginous configuration. The onset also is gradual, and it follows a more chronic course than AGEP. Exfoliative erythroderma presents with widespread erythema and superficial desquamating scale. It often occurs in association with systemic symptoms and can be the result of a drug reaction or underlying inflammatory dermatosis such as psoriasis, mycosis fungoides, or pityriasis rubra pilaris.

Acute generalized exanthematous pustulosis usually resolves spontaneously within 2 weeks and is associated with a superficial desquamation as it clears. Appropriate treatment includes discontinuing the offending agent; monitoring for systemic involvement; and treating the patient's symptoms with antihistamines, analgesics, topical steroids, and emollients. In more severe or persistent cases, treatment with systemic steroids and tumor necrosis factor α inhibitors has been attempted, though their efficacy remains unclear. We report a case of iopamidol-induced AGEP that highlights the importance of eliciting a history of contrast exposure from a patient with suspected AGEP.

The Diagnosis: Acute Generalized Exanthematous Pustulosis

Histopathology demonstrated spongiosis with subcorneal pustules and an overlying basket-weave pattern stratum corneum. There was mild papillary dermal edema with scattered dermal neutrophils and rare eosinophils (Figure). The patient's clinical presentation and histopathology were consistent with acute generalized exanthematous pustulosis (AGEP). The inciting agent in this case was the contrast medium iopamidol. The patient was treated with a short course of prednisone, triamcinolone cream, diphenhydramine, and acetaminophen. Within 1 week the pustules and erythema had resolved.

Acute generalized exanthematous pustulosis is an uncommon T cell-mediated cutaneous reaction characterized by widespread progressive erythema with numerous nonfollicular pinpoint pustules. The patient usually is well appearing; however, he/she often will have concurrent fever and facial edema. Mucous membranes rarely are involved. Laboratory results typically are notable only for leukocytosis with neutrophilia.

The pustular eruption typically occurs within 1 to 2 days after exposure to an inciting agent¹; however, this latent period can range from 1 hour to nearly 4 weeks in some studies.² Systemic medications are the cause in approximately 90% of cases, with antibiotics being the most common category. Frequently implicated medications include β-lactams, macrolides, quinolones, sulfonamides, proton pump inhibitors, hydroxychloroquine, terbinafine, nonsteroidal anti-inflammatory drugs, diltiazem, ketoconazole, and fluconazole. Acute generalized exanthematous pustulosis also has been rarely reported following contact with mercury, viral and bacterial infections, and spider bites.³

Iodinated contrast agents have long been known to cause immediate and delayed adverse cutaneous reactions. However, one consensus study indicated that these reactions occur in only 0.05% to 0.10% of patients.⁴ Although rare, iodinated contrast media (eg, iopamidol, iohexol, ioversol, iodixanol, iomeprol, iobitridol, iopromide) have been reported as a cause of AGEP. A PubMed search of articles indexed for MEDLINE using the terms acute generalized exanthematous pustulosis, contrast, iodine, and iodinated revealed 10 adult cases reported in 6 articles in the English-language literature.^1,5-9 The most recent articles focus on methods to identify the causative agent. If the etiology of the reaction is unclear, patch or intradermal testing can help to confirm the causative agent. These tests also can help determine similar agents to which the patient may cross-react.^4,5

It can be difficult to differentiate AGEP from other cutaneous drug reactions and other nonfollicular pustular conditions. Drug-induced hypersensitivity syndrome typically presents with facial edema and a morbilliform rash. Although it can present with pustules, the latent period is longer (2-6 weeks), and there frequently are signs of multiorgan involvement including hepatic dysfunction, eosinophilia, atypical lymphocytosis, and lymphadenopathy. Patients with generalized pustular psoriasis often have a history of plaque psoriasis; the pustules are more concentrated in flexural sites; the eruption is gradual in onset; and histologically there tends to be features of psoriasis including parakeratosis, Munro microabscesses, and dilated blood vessels.¹⁰ Subcorneal pustular dermatosis also is more concentrated in flexural sites and frequently has an annular or serpiginous configuration. The onset also is gradual, and it follows a more chronic course than AGEP. Exfoliative erythroderma presents with widespread erythema and superficial desquamating scale. It often occurs in association with systemic symptoms and can be the result of a drug reaction or underlying inflammatory dermatosis such as psoriasis, mycosis fungoides, or pityriasis rubra pilaris.

Acute generalized exanthematous pustulosis usually resolves spontaneously within 2 weeks and is associated with a superficial desquamation as it clears. Appropriate treatment includes discontinuing the offending agent; monitoring for systemic involvement; and treating the patient's symptoms with antihistamines, analgesics, topical steroids, and emollients. In more severe or persistent cases, treatment with systemic steroids and tumor necrosis factor α inhibitors has been attempted, though their efficacy remains unclear. We report a case of iopamidol-induced AGEP that highlights the importance of eliciting a history of contrast exposure from a patient with suspected AGEP.

The Diagnosis: Acute Generalized Exanthematous Pustulosis

Histopathology demonstrated spongiosis with subcorneal pustules and an overlying basket-weave pattern stratum corneum. There was mild papillary dermal edema with scattered dermal neutrophils and rare eosinophils (Figure). The patient's clinical presentation and histopathology were consistent with acute generalized exanthematous pustulosis (AGEP). The inciting agent in this case was the contrast medium iopamidol. The patient was treated with a short course of prednisone, triamcinolone cream, diphenhydramine, and acetaminophen. Within 1 week the pustules and erythema had resolved.

Acute generalized exanthematous pustulosis is an uncommon T cell-mediated cutaneous reaction characterized by widespread progressive erythema with numerous nonfollicular pinpoint pustules. The patient usually is well appearing; however, he/she often will have concurrent fever and facial edema. Mucous membranes rarely are involved. Laboratory results typically are notable only for leukocytosis with neutrophilia.

The pustular eruption typically occurs within 1 to 2 days after exposure to an inciting agent¹; however, this latent period can range from 1 hour to nearly 4 weeks in some studies.² Systemic medications are the cause in approximately 90% of cases, with antibiotics being the most common category. Frequently implicated medications include β-lactams, macrolides, quinolones, sulfonamides, proton pump inhibitors, hydroxychloroquine, terbinafine, nonsteroidal anti-inflammatory drugs, diltiazem, ketoconazole, and fluconazole. Acute generalized exanthematous pustulosis also has been rarely reported following contact with mercury, viral and bacterial infections, and spider bites.³

Iodinated contrast agents have long been known to cause immediate and delayed adverse cutaneous reactions. However, one consensus study indicated that these reactions occur in only 0.05% to 0.10% of patients.⁴ Although rare, iodinated contrast media (eg, iopamidol, iohexol, ioversol, iodixanol, iomeprol, iobitridol, iopromide) have been reported as a cause of AGEP. A PubMed search of articles indexed for MEDLINE using the terms acute generalized exanthematous pustulosis, contrast, iodine, and iodinated revealed 10 adult cases reported in 6 articles in the English-language literature.^1,5-9 The most recent articles focus on methods to identify the causative agent. If the etiology of the reaction is unclear, patch or intradermal testing can help to confirm the causative agent. These tests also can help determine similar agents to which the patient may cross-react.^4,5

It can be difficult to differentiate AGEP from other cutaneous drug reactions and other nonfollicular pustular conditions. Drug-induced hypersensitivity syndrome typically presents with facial edema and a morbilliform rash. Although it can present with pustules, the latent period is longer (2-6 weeks), and there frequently are signs of multiorgan involvement including hepatic dysfunction, eosinophilia, atypical lymphocytosis, and lymphadenopathy. Patients with generalized pustular psoriasis often have a history of plaque psoriasis; the pustules are more concentrated in flexural sites; the eruption is gradual in onset; and histologically there tends to be features of psoriasis including parakeratosis, Munro microabscesses, and dilated blood vessels.¹⁰ Subcorneal pustular dermatosis also is more concentrated in flexural sites and frequently has an annular or serpiginous configuration. The onset also is gradual, and it follows a more chronic course than AGEP. Exfoliative erythroderma presents with widespread erythema and superficial desquamating scale. It often occurs in association with systemic symptoms and can be the result of a drug reaction or underlying inflammatory dermatosis such as psoriasis, mycosis fungoides, or pityriasis rubra pilaris.

Acute generalized exanthematous pustulosis usually resolves spontaneously within 2 weeks and is associated with a superficial desquamation as it clears. Appropriate treatment includes discontinuing the offending agent; monitoring for systemic involvement; and treating the patient's symptoms with antihistamines, analgesics, topical steroids, and emollients. In more severe or persistent cases, treatment with systemic steroids and tumor necrosis factor α inhibitors has been attempted, though their efficacy remains unclear. We report a case of iopamidol-induced AGEP that highlights the importance of eliciting a history of contrast exposure from a patient with suspected AGEP.

‌

‌

‌

‌

‌

‌

Pilonidal disease was first described by Mayo¹ in 1833 who hypothesized that the underlying etiology is incomplete separation of the mesoderm and ectoderm layers during embryogenesis. In 1880, Hodges² coined the term pilonidal sinus; he postulated that sinus formation was incited by hair.² Today, Hodges theory is known as the acquired theory: hair induces a foreign body response in surrounding tissue, leading to sinus formation. Although pilonidal cysts can occur anywhere on the body, they most commonly extend cephalad in the sacrococcygeal and upper gluteal cleft (Figure 1).^3,4 An acute pilonidal cyst typically presents with pain, tenderness, and swelling, similar to the presentation of a superficial abscess in other locations; however, a clue to the diagnosis is the presence of cutaneous pits along the midline of the gluteal cleft.⁵ Chronic pilonidal disease varies based on the extent of inflammation and scarring; the underlying cavity communicates with the overlying skin through sinuses and often drains with pressure.⁶

Pilonidal sinuses are rare before puberty or after 40 years of age⁷ and occur primarily in hirsute men. The ratio of men to women affected is between 3:1 and 4:1.⁸ Although pilonidal sinuses account for only 15% of anal suppurations, complications arising from pilonidal sinuses are a considerable cause of morbidity, resulting in loss of productivity in otherwise healthy individuals.⁹ Complications include chronic nonhealing wounds,¹⁰ as recurrent pilonidal sinuses tend to become colonized with gram-positive and facultative anaerobic bacteria, whereas primary pilonidal cysts more commonly become infected with anaerobic and gram-negative bacteria.¹¹ Long-standing disease increases the risk of squamous cell carcinoma arising within sinus tracts.^10,12

Histopathologically, pilonidal cysts are not true cysts because they lack an epithelial lining. Examination of the cavity commonly reveals hair, debris, and granulation tissue with surrounding foreign-body giant cells (Figure 2).⁵

The preferred treatment of pilonidal cysts continues to be debated. In this article, we review evidence supporting current modalities including conservative and surgical techniques as well as novel laser therapy for the treatment of pilonidal disease.

Conservative Management Techniques

Phenol Injections
Liquid or crystallized phenol injections have been used for treatment of mild to moderate pilonidal cysts.¹³ Excess debris is removed by curettage, and phenol is administered through the existing orifices or pits without pressure. The phenol remains in the cavity for 1 to 3 minutes before aspiration. Remaining cyst contents are removed through tissue manipulation, and the sinus is washed with saline. Mean healing time is 20 days (range, +/−14 days).¹³

Classically, phenol injections have a failure rate of 30% to 40%, especially with multiple sinuses and suppurative disease⁶; however, the success rate improves with limited disease (ie, no more than 1–3 sinus pits).³ With multiple treatment sessions, a recurrence rate as low as 2% over 25 months has been reported.¹⁴ Phenol injection also has been proposed as an adjuvant therapy to pit excision to minimize the need for extensive surgery.¹⁵

Simple Incision and Drainage
Simple incision and drainage has a crucial role in the treatment of acute pilonidal disease to decrease pain and relieve tension. Off-midline incisions have been recommended for because the resulting closures fared better against sheer forces applied by the gluteal muscles on the cleft.⁶ Therefore, the incision often is made off-midline from the gluteal cleft even when the cyst lies directly on the gluteal cleft.

Rates of healing vary widely after incision and drainage, ranging from 45% to 82%.⁶ Primary pilonidal cysts may respond well, particularly if the cavity is abraded; in one series, 79% (58/73) of patients did not have a recurrence at the average follow-up of 60 months.¹⁶

Excision and Unroofing
Techniques for excision and unroofing without primary closure include 2 variants: wide and limited. The wide technique consists of an inwardly slanted excision that is deepest in the center of the cavity. The inward sloping angle of the incision aids in healing because it allows granulation to progress evenly from the base of the wound upward. The depth of the incision should spare the fascia and leave as much fatty tissue as possible while still resecting the entire cavity and associated pits.⁶ Limited incision techniques aim to shorten the healing period by making smaller incisions into the sinuses, pits, and secondary tracts, and they are frequently supplemented with curettage.⁶ Noteworthy disadvantages include prolonged healing time, need for professional wound management, and extended medical observation.⁵ The average duration of wound healing in a study of 300 patients was 5.4 weeks (range, +/−1.1 weeks),¹⁷ and the recurrence rate has ranged from 5% to 13%.^18,19 Care must be taken to respond to numerous possible complications, including excessive exudation and granulation, superinfection, and walling off.⁶

Although the cost of treatment varies by hospital, location, and a patient’s insurance coverage, patient reports to the Pilonidal Support Alliance indicate that the cost of conservative management ranges from $500 to $2000.²⁰

Excision and Primary Closure
An elliptical excision that includes some of the lateral margin is excised down to the level of the fascia. Adjacent lateral tracts may be excised by expanding the incision. To close the wound, edges are approximated with placement of deep and superficial sutures. Wound healing typically occurs faster than secondary granulation, as seen in one randomized controlled trial with a mean of 10 days for primary closure compared to 13 weeks for secondary intention.²¹ However, as with any surgical procedure, postoperative complications can delay wound healing.¹⁹ The recurrence rate after primary closure varies considerably, ranging from 10% to 38%.^18,21-23 The average cost of an excision ranges from $3000 to $6000.²⁰

A Cochrane review evaluated 26 studies comparing primary and secondary closure. This large analysis showed no clear benefit for open healing over surgical closure²⁴; however, off-midline closure showed statistically significant benefit over midline closure (mean difference, 5.4 days; 95% CI, 2.3-8.5), and many experts now consider off-midline closure the standard of care in pilonidal sinus management (Figure 3).^24,25

Surgical Techniques

For severe or recurrent pilonidal disease, skin flaps often are required. Several flaps have been developed, including advancement, Bascom cleft lift, Karydakis, and modified Limberg flap. Flaps require a vascular pedicle but allow for closure without tension.²⁶ The cost of a flap procedure, ranging from $10,000 to $30,000, is greater than the cost of excision or other conservative therapy²⁰; however, with a lower recurrence rate of pilonidal disease following flap procedures compared to other treatments, patients may save more on treatment over the long-term.

Advancement Flaps
The most commonly used advancement flaps are the V-Y advancement flap and Z-plasty. The V-Y advancement flap creates a full-thickness V-shaped incision down to gluteal fascia that is closed to form a postrepair suture line in the shape of a Y.⁵ Depending on the size of the defect, the flaps may be utilized unilaterally or bilaterally. A defect as large as 8 to 10 cm can be covered unilaterally; however, defects larger than 10 cm commonly require a bilateral flap.²⁶ The V-Y advancement flap failed to show superiority to primary closure techniques based on complications, recurrence, and patient satisfaction in a large randomized controlled trial.²⁷

Performing a Z-plasty requires excision of diseased tissue with recruitment of lateral flaps incised down to the level of the fascia. The lateral edges are transposed to increase transverse length.²⁶ No statistically significant difference in infection or recurrence rates was noted between excision alone and excision plus Z-plasty; however, wounds were reported to heal faster in patients receiving excision plus Z-plasty (41 vs 15 days).²⁸

Cleft Lift Closure
In 1987, Bascom²⁹ introduced the cleft lift closure for recurrent pilonidal disease. This technique aims to reduce or eliminate lateral gluteal forces on the wounds by filling the gluteal cleft.⁵ The sinus tracts are excised and a full-thickness skin flap is extended across the cleft and closed off-midline. The adipose tissue fills in the previous space of the gluteal cleft. In the initial study, no recurrences were reported in 30 patients who underwent this procedure at 2-year follow-up; similarly, in another case series of 26 patients who underwent the procedure, no recurrences were noted at a median follow-up of 3 years.³⁰ Compared to excision with secondary wound healing and primary closure on the midline, the Bascom cleft lift demonstrated a decrease in wound healing time (62, 52, and 29 days, respectively).³¹

The classic Karydakis flap consists of an oblique elliptical excision of diseased tissue with fixation of the flap base to the sacral fascia (Figures 4 and 5). The flap is closed by suturing the edge off-midline.³² This technique prevents a midline wound and aims to remodel and flatten the natal cleft. Karydakis³³ performed the most important study for treatment of pilonidal disease with the Karydakis flap, which included more than 5000 patients. The results showed a 0.9% recurrence rate and an 8.5% wound complication rate over a 2- to 20-year follow-up.³³ These results have been substantiated by more recent studies, which produced similar results: a 1.8% to 5.3% infection rate and a recurrence rate of 0.9% to 4.4%.^34,35

In the modified Karydakis flap, the same excision and closure is performed without tacking the flap to the sacral fascia, aiming to prevent formation of a new vulnerable raphe by flattening the natal cleft. The infection rate was similar to the classic Karydakis flap, and no recurrences were noted during a 20-month follow-up.³⁶

Limberg Flap
The Limberg flap is derived from a rhomboid flap. In the classic Limberg flap, a midline rhomboid incision to the presacral fascia including the sinus is performed. The flap gains mobility by extending the excision laterally to the fascia of the gluteus maximus muscle. A variant of the original flap includes the modified Limberg flap, which lateralizes the midline sutures and flattens the intergluteal sulcus. Compared to the traditional Limberg approach, the modified Limberg flap was associated with a lower failure rate at both early and late time points and a lower rate of infection^37,38; however, based on the data it is unclear when primary closure should be favored over a Limberg flap. Several studies show the recurrence rate to be identical; however, hospital stay and pain were reduced in the Limberg flap group compared to primary closure.^39,40

Results from randomized controlled trials comparing the modified Limberg flap to the Karydakis flap vary. One of the largest prospective, randomized, controlled trials comparing the 2 flaps included 269 patients.Results showed a lower postoperative complication rate, lower pain scores, shorter operation time, and shorter hospital stay with the Karydakis flap compared to the Limberg flap, though no difference in recurrence was noted between the 2 groups.⁴¹

Two randomized controlled trials comprising 145 and 120 patients, respectively, showed no statistically significant difference between the Limberg flap and Karydakis flap with regard to complication rate, length of stay, and recurrence rate^36,42; however, patients in the Karydakis group reported subjectively feeling healed more quickly than patients in the modified Limberg flap group,⁴² and 1 of the 2 studies showed an increase in patient satisfaction with the modified Karydakis flap compared to modified Limberg flap.³⁶ In contrast to earlier studies, a 2009 study showed the Karydakis flap was associated with a higher wound infection rate than the Limberg flap group in a randomized trial of 100 patients (13/50 vs 4/50 patients).⁴³

Overall, larger prospective trials are needed to clarify the differences in outcomes between flap techniques. In our opinion, variations in postoperative complication and recurrence rates likely are due to differences in surgeon comfort and surgical technique. The Table provides a comprehensive list of trials comparing flap techniques.

Laser Therapy

Lasers are emerging as primary and adjuvant treatment options for pilonidal sinuses. Depilation with alexandrite, diode, and Nd:YAG lasers has demonstrated the most consistent evidence.^50-54 The firm texture and quality of the hair is proposed to incite an inflammatory response with sinus formation; therefore, using a laser to permaently remove this factor may help prevent future disease.

Large randomized controlled trials are needed to fully determine the utility of laser therapy as a primary or adjuvant treatment in pilonidal disease; however, given that laser therapies address the core pathogenesis of pilonidal disease and generally are well tolerated, their use may be strongly considered.

Conclusion

With mild pilonidal disease, more conservative measures can be employed; however, in cases of recurrent or suppurative disease or extensive scarring, excision with flap closure typically is required. Although no single surgical procedure has been identified as superior, one review demonstrated that off-midline procedures are statistically superior to midline closure in healing time, surgical site infection, and recurrence rate.²⁴ Novel techniques continue to emerge in the management of pilonidal disease, including laser therapy. This modality shows promise as either a primary or adjuvant treatment; however, large randomized controlled trials are needed to confirm early findings.

Given that pilonidal disease most commonly occurs in the actively employed population, we recommend that dermatologic surgeons discuss treatment options with patients who have pilonidal disease, taking into consideration cost, length of hospital stay, and recovery time when deciding on a treatment course.

Pilonidal disease was first described by Mayo¹ in 1833 who hypothesized that the underlying etiology is incomplete separation of the mesoderm and ectoderm layers during embryogenesis. In 1880, Hodges² coined the term pilonidal sinus; he postulated that sinus formation was incited by hair.² Today, Hodges theory is known as the acquired theory: hair induces a foreign body response in surrounding tissue, leading to sinus formation. Although pilonidal cysts can occur anywhere on the body, they most commonly extend cephalad in the sacrococcygeal and upper gluteal cleft (Figure 1).^3,4 An acute pilonidal cyst typically presents with pain, tenderness, and swelling, similar to the presentation of a superficial abscess in other locations; however, a clue to the diagnosis is the presence of cutaneous pits along the midline of the gluteal cleft.⁵ Chronic pilonidal disease varies based on the extent of inflammation and scarring; the underlying cavity communicates with the overlying skin through sinuses and often drains with pressure.⁶

Pilonidal sinuses are rare before puberty or after 40 years of age⁷ and occur primarily in hirsute men. The ratio of men to women affected is between 3:1 and 4:1.⁸ Although pilonidal sinuses account for only 15% of anal suppurations, complications arising from pilonidal sinuses are a considerable cause of morbidity, resulting in loss of productivity in otherwise healthy individuals.⁹ Complications include chronic nonhealing wounds,¹⁰ as recurrent pilonidal sinuses tend to become colonized with gram-positive and facultative anaerobic bacteria, whereas primary pilonidal cysts more commonly become infected with anaerobic and gram-negative bacteria.¹¹ Long-standing disease increases the risk of squamous cell carcinoma arising within sinus tracts.^10,12

Histopathologically, pilonidal cysts are not true cysts because they lack an epithelial lining. Examination of the cavity commonly reveals hair, debris, and granulation tissue with surrounding foreign-body giant cells (Figure 2).⁵

The preferred treatment of pilonidal cysts continues to be debated. In this article, we review evidence supporting current modalities including conservative and surgical techniques as well as novel laser therapy for the treatment of pilonidal disease.

Conservative Management Techniques

Phenol Injections
Liquid or crystallized phenol injections have been used for treatment of mild to moderate pilonidal cysts.¹³ Excess debris is removed by curettage, and phenol is administered through the existing orifices or pits without pressure. The phenol remains in the cavity for 1 to 3 minutes before aspiration. Remaining cyst contents are removed through tissue manipulation, and the sinus is washed with saline. Mean healing time is 20 days (range, +/−14 days).¹³

Classically, phenol injections have a failure rate of 30% to 40%, especially with multiple sinuses and suppurative disease⁶; however, the success rate improves with limited disease (ie, no more than 1–3 sinus pits).³ With multiple treatment sessions, a recurrence rate as low as 2% over 25 months has been reported.¹⁴ Phenol injection also has been proposed as an adjuvant therapy to pit excision to minimize the need for extensive surgery.¹⁵

Simple Incision and Drainage
Simple incision and drainage has a crucial role in the treatment of acute pilonidal disease to decrease pain and relieve tension. Off-midline incisions have been recommended for because the resulting closures fared better against sheer forces applied by the gluteal muscles on the cleft.⁶ Therefore, the incision often is made off-midline from the gluteal cleft even when the cyst lies directly on the gluteal cleft.

Rates of healing vary widely after incision and drainage, ranging from 45% to 82%.⁶ Primary pilonidal cysts may respond well, particularly if the cavity is abraded; in one series, 79% (58/73) of patients did not have a recurrence at the average follow-up of 60 months.¹⁶

Excision and Unroofing
Techniques for excision and unroofing without primary closure include 2 variants: wide and limited. The wide technique consists of an inwardly slanted excision that is deepest in the center of the cavity. The inward sloping angle of the incision aids in healing because it allows granulation to progress evenly from the base of the wound upward. The depth of the incision should spare the fascia and leave as much fatty tissue as possible while still resecting the entire cavity and associated pits.⁶ Limited incision techniques aim to shorten the healing period by making smaller incisions into the sinuses, pits, and secondary tracts, and they are frequently supplemented with curettage.⁶ Noteworthy disadvantages include prolonged healing time, need for professional wound management, and extended medical observation.⁵ The average duration of wound healing in a study of 300 patients was 5.4 weeks (range, +/−1.1 weeks),¹⁷ and the recurrence rate has ranged from 5% to 13%.^18,19 Care must be taken to respond to numerous possible complications, including excessive exudation and granulation, superinfection, and walling off.⁶

Although the cost of treatment varies by hospital, location, and a patient’s insurance coverage, patient reports to the Pilonidal Support Alliance indicate that the cost of conservative management ranges from $500 to $2000.²⁰

Excision and Primary Closure
An elliptical excision that includes some of the lateral margin is excised down to the level of the fascia. Adjacent lateral tracts may be excised by expanding the incision. To close the wound, edges are approximated with placement of deep and superficial sutures. Wound healing typically occurs faster than secondary granulation, as seen in one randomized controlled trial with a mean of 10 days for primary closure compared to 13 weeks for secondary intention.²¹ However, as with any surgical procedure, postoperative complications can delay wound healing.¹⁹ The recurrence rate after primary closure varies considerably, ranging from 10% to 38%.^18,21-23 The average cost of an excision ranges from $3000 to $6000.²⁰

A Cochrane review evaluated 26 studies comparing primary and secondary closure. This large analysis showed no clear benefit for open healing over surgical closure²⁴; however, off-midline closure showed statistically significant benefit over midline closure (mean difference, 5.4 days; 95% CI, 2.3-8.5), and many experts now consider off-midline closure the standard of care in pilonidal sinus management (Figure 3).^24,25

Surgical Techniques

For severe or recurrent pilonidal disease, skin flaps often are required. Several flaps have been developed, including advancement, Bascom cleft lift, Karydakis, and modified Limberg flap. Flaps require a vascular pedicle but allow for closure without tension.²⁶ The cost of a flap procedure, ranging from $10,000 to $30,000, is greater than the cost of excision or other conservative therapy²⁰; however, with a lower recurrence rate of pilonidal disease following flap procedures compared to other treatments, patients may save more on treatment over the long-term.

Advancement Flaps
The most commonly used advancement flaps are the V-Y advancement flap and Z-plasty. The V-Y advancement flap creates a full-thickness V-shaped incision down to gluteal fascia that is closed to form a postrepair suture line in the shape of a Y.⁵ Depending on the size of the defect, the flaps may be utilized unilaterally or bilaterally. A defect as large as 8 to 10 cm can be covered unilaterally; however, defects larger than 10 cm commonly require a bilateral flap.²⁶ The V-Y advancement flap failed to show superiority to primary closure techniques based on complications, recurrence, and patient satisfaction in a large randomized controlled trial.²⁷

Performing a Z-plasty requires excision of diseased tissue with recruitment of lateral flaps incised down to the level of the fascia. The lateral edges are transposed to increase transverse length.²⁶ No statistically significant difference in infection or recurrence rates was noted between excision alone and excision plus Z-plasty; however, wounds were reported to heal faster in patients receiving excision plus Z-plasty (41 vs 15 days).²⁸

Cleft Lift Closure
In 1987, Bascom²⁹ introduced the cleft lift closure for recurrent pilonidal disease. This technique aims to reduce or eliminate lateral gluteal forces on the wounds by filling the gluteal cleft.⁵ The sinus tracts are excised and a full-thickness skin flap is extended across the cleft and closed off-midline. The adipose tissue fills in the previous space of the gluteal cleft. In the initial study, no recurrences were reported in 30 patients who underwent this procedure at 2-year follow-up; similarly, in another case series of 26 patients who underwent the procedure, no recurrences were noted at a median follow-up of 3 years.³⁰ Compared to excision with secondary wound healing and primary closure on the midline, the Bascom cleft lift demonstrated a decrease in wound healing time (62, 52, and 29 days, respectively).³¹

The classic Karydakis flap consists of an oblique elliptical excision of diseased tissue with fixation of the flap base to the sacral fascia (Figures 4 and 5). The flap is closed by suturing the edge off-midline.³² This technique prevents a midline wound and aims to remodel and flatten the natal cleft. Karydakis³³ performed the most important study for treatment of pilonidal disease with the Karydakis flap, which included more than 5000 patients. The results showed a 0.9% recurrence rate and an 8.5% wound complication rate over a 2- to 20-year follow-up.³³ These results have been substantiated by more recent studies, which produced similar results: a 1.8% to 5.3% infection rate and a recurrence rate of 0.9% to 4.4%.^34,35

In the modified Karydakis flap, the same excision and closure is performed without tacking the flap to the sacral fascia, aiming to prevent formation of a new vulnerable raphe by flattening the natal cleft. The infection rate was similar to the classic Karydakis flap, and no recurrences were noted during a 20-month follow-up.³⁶

Limberg Flap
The Limberg flap is derived from a rhomboid flap. In the classic Limberg flap, a midline rhomboid incision to the presacral fascia including the sinus is performed. The flap gains mobility by extending the excision laterally to the fascia of the gluteus maximus muscle. A variant of the original flap includes the modified Limberg flap, which lateralizes the midline sutures and flattens the intergluteal sulcus. Compared to the traditional Limberg approach, the modified Limberg flap was associated with a lower failure rate at both early and late time points and a lower rate of infection^37,38; however, based on the data it is unclear when primary closure should be favored over a Limberg flap. Several studies show the recurrence rate to be identical; however, hospital stay and pain were reduced in the Limberg flap group compared to primary closure.^39,40

Results from randomized controlled trials comparing the modified Limberg flap to the Karydakis flap vary. One of the largest prospective, randomized, controlled trials comparing the 2 flaps included 269 patients.Results showed a lower postoperative complication rate, lower pain scores, shorter operation time, and shorter hospital stay with the Karydakis flap compared to the Limberg flap, though no difference in recurrence was noted between the 2 groups.⁴¹

Two randomized controlled trials comprising 145 and 120 patients, respectively, showed no statistically significant difference between the Limberg flap and Karydakis flap with regard to complication rate, length of stay, and recurrence rate^36,42; however, patients in the Karydakis group reported subjectively feeling healed more quickly than patients in the modified Limberg flap group,⁴² and 1 of the 2 studies showed an increase in patient satisfaction with the modified Karydakis flap compared to modified Limberg flap.³⁶ In contrast to earlier studies, a 2009 study showed the Karydakis flap was associated with a higher wound infection rate than the Limberg flap group in a randomized trial of 100 patients (13/50 vs 4/50 patients).⁴³

Overall, larger prospective trials are needed to clarify the differences in outcomes between flap techniques. In our opinion, variations in postoperative complication and recurrence rates likely are due to differences in surgeon comfort and surgical technique. The Table provides a comprehensive list of trials comparing flap techniques.

Laser Therapy

Lasers are emerging as primary and adjuvant treatment options for pilonidal sinuses. Depilation with alexandrite, diode, and Nd:YAG lasers has demonstrated the most consistent evidence.^50-54 The firm texture and quality of the hair is proposed to incite an inflammatory response with sinus formation; therefore, using a laser to permaently remove this factor may help prevent future disease.

Large randomized controlled trials are needed to fully determine the utility of laser therapy as a primary or adjuvant treatment in pilonidal disease; however, given that laser therapies address the core pathogenesis of pilonidal disease and generally are well tolerated, their use may be strongly considered.

Conclusion

With mild pilonidal disease, more conservative measures can be employed; however, in cases of recurrent or suppurative disease or extensive scarring, excision with flap closure typically is required. Although no single surgical procedure has been identified as superior, one review demonstrated that off-midline procedures are statistically superior to midline closure in healing time, surgical site infection, and recurrence rate.²⁴ Novel techniques continue to emerge in the management of pilonidal disease, including laser therapy. This modality shows promise as either a primary or adjuvant treatment; however, large randomized controlled trials are needed to confirm early findings.

Given that pilonidal disease most commonly occurs in the actively employed population, we recommend that dermatologic surgeons discuss treatment options with patients who have pilonidal disease, taking into consideration cost, length of hospital stay, and recovery time when deciding on a treatment course.

Pilonidal disease was first described by Mayo¹ in 1833 who hypothesized that the underlying etiology is incomplete separation of the mesoderm and ectoderm layers during embryogenesis. In 1880, Hodges² coined the term pilonidal sinus; he postulated that sinus formation was incited by hair.² Today, Hodges theory is known as the acquired theory: hair induces a foreign body response in surrounding tissue, leading to sinus formation. Although pilonidal cysts can occur anywhere on the body, they most commonly extend cephalad in the sacrococcygeal and upper gluteal cleft (Figure 1).^3,4 An acute pilonidal cyst typically presents with pain, tenderness, and swelling, similar to the presentation of a superficial abscess in other locations; however, a clue to the diagnosis is the presence of cutaneous pits along the midline of the gluteal cleft.⁵ Chronic pilonidal disease varies based on the extent of inflammation and scarring; the underlying cavity communicates with the overlying skin through sinuses and often drains with pressure.⁶

Pilonidal sinuses are rare before puberty or after 40 years of age⁷ and occur primarily in hirsute men. The ratio of men to women affected is between 3:1 and 4:1.⁸ Although pilonidal sinuses account for only 15% of anal suppurations, complications arising from pilonidal sinuses are a considerable cause of morbidity, resulting in loss of productivity in otherwise healthy individuals.⁹ Complications include chronic nonhealing wounds,¹⁰ as recurrent pilonidal sinuses tend to become colonized with gram-positive and facultative anaerobic bacteria, whereas primary pilonidal cysts more commonly become infected with anaerobic and gram-negative bacteria.¹¹ Long-standing disease increases the risk of squamous cell carcinoma arising within sinus tracts.^10,12

Histopathologically, pilonidal cysts are not true cysts because they lack an epithelial lining. Examination of the cavity commonly reveals hair, debris, and granulation tissue with surrounding foreign-body giant cells (Figure 2).⁵

The preferred treatment of pilonidal cysts continues to be debated. In this article, we review evidence supporting current modalities including conservative and surgical techniques as well as novel laser therapy for the treatment of pilonidal disease.

Conservative Management Techniques

Phenol Injections
Liquid or crystallized phenol injections have been used for treatment of mild to moderate pilonidal cysts.¹³ Excess debris is removed by curettage, and phenol is administered through the existing orifices or pits without pressure. The phenol remains in the cavity for 1 to 3 minutes before aspiration. Remaining cyst contents are removed through tissue manipulation, and the sinus is washed with saline. Mean healing time is 20 days (range, +/−14 days).¹³

Classically, phenol injections have a failure rate of 30% to 40%, especially with multiple sinuses and suppurative disease⁶; however, the success rate improves with limited disease (ie, no more than 1–3 sinus pits).³ With multiple treatment sessions, a recurrence rate as low as 2% over 25 months has been reported.¹⁴ Phenol injection also has been proposed as an adjuvant therapy to pit excision to minimize the need for extensive surgery.¹⁵

Simple Incision and Drainage
Simple incision and drainage has a crucial role in the treatment of acute pilonidal disease to decrease pain and relieve tension. Off-midline incisions have been recommended for because the resulting closures fared better against sheer forces applied by the gluteal muscles on the cleft.⁶ Therefore, the incision often is made off-midline from the gluteal cleft even when the cyst lies directly on the gluteal cleft.

Rates of healing vary widely after incision and drainage, ranging from 45% to 82%.⁶ Primary pilonidal cysts may respond well, particularly if the cavity is abraded; in one series, 79% (58/73) of patients did not have a recurrence at the average follow-up of 60 months.¹⁶

Excision and Unroofing
Techniques for excision and unroofing without primary closure include 2 variants: wide and limited. The wide technique consists of an inwardly slanted excision that is deepest in the center of the cavity. The inward sloping angle of the incision aids in healing because it allows granulation to progress evenly from the base of the wound upward. The depth of the incision should spare the fascia and leave as much fatty tissue as possible while still resecting the entire cavity and associated pits.⁶ Limited incision techniques aim to shorten the healing period by making smaller incisions into the sinuses, pits, and secondary tracts, and they are frequently supplemented with curettage.⁶ Noteworthy disadvantages include prolonged healing time, need for professional wound management, and extended medical observation.⁵ The average duration of wound healing in a study of 300 patients was 5.4 weeks (range, +/−1.1 weeks),¹⁷ and the recurrence rate has ranged from 5% to 13%.^18,19 Care must be taken to respond to numerous possible complications, including excessive exudation and granulation, superinfection, and walling off.⁶

Although the cost of treatment varies by hospital, location, and a patient’s insurance coverage, patient reports to the Pilonidal Support Alliance indicate that the cost of conservative management ranges from $500 to $2000.²⁰

Excision and Primary Closure
An elliptical excision that includes some of the lateral margin is excised down to the level of the fascia. Adjacent lateral tracts may be excised by expanding the incision. To close the wound, edges are approximated with placement of deep and superficial sutures. Wound healing typically occurs faster than secondary granulation, as seen in one randomized controlled trial with a mean of 10 days for primary closure compared to 13 weeks for secondary intention.²¹ However, as with any surgical procedure, postoperative complications can delay wound healing.¹⁹ The recurrence rate after primary closure varies considerably, ranging from 10% to 38%.^18,21-23 The average cost of an excision ranges from $3000 to $6000.²⁰

A Cochrane review evaluated 26 studies comparing primary and secondary closure. This large analysis showed no clear benefit for open healing over surgical closure²⁴; however, off-midline closure showed statistically significant benefit over midline closure (mean difference, 5.4 days; 95% CI, 2.3-8.5), and many experts now consider off-midline closure the standard of care in pilonidal sinus management (Figure 3).^24,25

Surgical Techniques

For severe or recurrent pilonidal disease, skin flaps often are required. Several flaps have been developed, including advancement, Bascom cleft lift, Karydakis, and modified Limberg flap. Flaps require a vascular pedicle but allow for closure without tension.²⁶ The cost of a flap procedure, ranging from $10,000 to $30,000, is greater than the cost of excision or other conservative therapy²⁰; however, with a lower recurrence rate of pilonidal disease following flap procedures compared to other treatments, patients may save more on treatment over the long-term.

Advancement Flaps
The most commonly used advancement flaps are the V-Y advancement flap and Z-plasty. The V-Y advancement flap creates a full-thickness V-shaped incision down to gluteal fascia that is closed to form a postrepair suture line in the shape of a Y.⁵ Depending on the size of the defect, the flaps may be utilized unilaterally or bilaterally. A defect as large as 8 to 10 cm can be covered unilaterally; however, defects larger than 10 cm commonly require a bilateral flap.²⁶ The V-Y advancement flap failed to show superiority to primary closure techniques based on complications, recurrence, and patient satisfaction in a large randomized controlled trial.²⁷

Performing a Z-plasty requires excision of diseased tissue with recruitment of lateral flaps incised down to the level of the fascia. The lateral edges are transposed to increase transverse length.²⁶ No statistically significant difference in infection or recurrence rates was noted between excision alone and excision plus Z-plasty; however, wounds were reported to heal faster in patients receiving excision plus Z-plasty (41 vs 15 days).²⁸

Cleft Lift Closure
In 1987, Bascom²⁹ introduced the cleft lift closure for recurrent pilonidal disease. This technique aims to reduce or eliminate lateral gluteal forces on the wounds by filling the gluteal cleft.⁵ The sinus tracts are excised and a full-thickness skin flap is extended across the cleft and closed off-midline. The adipose tissue fills in the previous space of the gluteal cleft. In the initial study, no recurrences were reported in 30 patients who underwent this procedure at 2-year follow-up; similarly, in another case series of 26 patients who underwent the procedure, no recurrences were noted at a median follow-up of 3 years.³⁰ Compared to excision with secondary wound healing and primary closure on the midline, the Bascom cleft lift demonstrated a decrease in wound healing time (62, 52, and 29 days, respectively).³¹

The classic Karydakis flap consists of an oblique elliptical excision of diseased tissue with fixation of the flap base to the sacral fascia (Figures 4 and 5). The flap is closed by suturing the edge off-midline.³² This technique prevents a midline wound and aims to remodel and flatten the natal cleft. Karydakis³³ performed the most important study for treatment of pilonidal disease with the Karydakis flap, which included more than 5000 patients. The results showed a 0.9% recurrence rate and an 8.5% wound complication rate over a 2- to 20-year follow-up.³³ These results have been substantiated by more recent studies, which produced similar results: a 1.8% to 5.3% infection rate and a recurrence rate of 0.9% to 4.4%.^34,35

In the modified Karydakis flap, the same excision and closure is performed without tacking the flap to the sacral fascia, aiming to prevent formation of a new vulnerable raphe by flattening the natal cleft. The infection rate was similar to the classic Karydakis flap, and no recurrences were noted during a 20-month follow-up.³⁶

Limberg Flap
The Limberg flap is derived from a rhomboid flap. In the classic Limberg flap, a midline rhomboid incision to the presacral fascia including the sinus is performed. The flap gains mobility by extending the excision laterally to the fascia of the gluteus maximus muscle. A variant of the original flap includes the modified Limberg flap, which lateralizes the midline sutures and flattens the intergluteal sulcus. Compared to the traditional Limberg approach, the modified Limberg flap was associated with a lower failure rate at both early and late time points and a lower rate of infection^37,38; however, based on the data it is unclear when primary closure should be favored over a Limberg flap. Several studies show the recurrence rate to be identical; however, hospital stay and pain were reduced in the Limberg flap group compared to primary closure.^39,40

Results from randomized controlled trials comparing the modified Limberg flap to the Karydakis flap vary. One of the largest prospective, randomized, controlled trials comparing the 2 flaps included 269 patients.Results showed a lower postoperative complication rate, lower pain scores, shorter operation time, and shorter hospital stay with the Karydakis flap compared to the Limberg flap, though no difference in recurrence was noted between the 2 groups.⁴¹

Two randomized controlled trials comprising 145 and 120 patients, respectively, showed no statistically significant difference between the Limberg flap and Karydakis flap with regard to complication rate, length of stay, and recurrence rate^36,42; however, patients in the Karydakis group reported subjectively feeling healed more quickly than patients in the modified Limberg flap group,⁴² and 1 of the 2 studies showed an increase in patient satisfaction with the modified Karydakis flap compared to modified Limberg flap.³⁶ In contrast to earlier studies, a 2009 study showed the Karydakis flap was associated with a higher wound infection rate than the Limberg flap group in a randomized trial of 100 patients (13/50 vs 4/50 patients).⁴³

Overall, larger prospective trials are needed to clarify the differences in outcomes between flap techniques. In our opinion, variations in postoperative complication and recurrence rates likely are due to differences in surgeon comfort and surgical technique. The Table provides a comprehensive list of trials comparing flap techniques.

Laser Therapy

Lasers are emerging as primary and adjuvant treatment options for pilonidal sinuses. Depilation with alexandrite, diode, and Nd:YAG lasers has demonstrated the most consistent evidence.^50-54 The firm texture and quality of the hair is proposed to incite an inflammatory response with sinus formation; therefore, using a laser to permaently remove this factor may help prevent future disease.

Large randomized controlled trials are needed to fully determine the utility of laser therapy as a primary or adjuvant treatment in pilonidal disease; however, given that laser therapies address the core pathogenesis of pilonidal disease and generally are well tolerated, their use may be strongly considered.

Conclusion

With mild pilonidal disease, more conservative measures can be employed; however, in cases of recurrent or suppurative disease or extensive scarring, excision with flap closure typically is required. Although no single surgical procedure has been identified as superior, one review demonstrated that off-midline procedures are statistically superior to midline closure in healing time, surgical site infection, and recurrence rate.²⁴ Novel techniques continue to emerge in the management of pilonidal disease, including laser therapy. This modality shows promise as either a primary or adjuvant treatment; however, large randomized controlled trials are needed to confirm early findings.

Given that pilonidal disease most commonly occurs in the actively employed population, we recommend that dermatologic surgeons discuss treatment options with patients who have pilonidal disease, taking into consideration cost, length of hospital stay, and recovery time when deciding on a treatment course.

Fibrofolliculomas and trichodiscomas typically present on the head or neck as smooth, flesh-colored, dome-shaped papules. These two entities are considered to constitute two separate time points on a spectrum of histopathologic changes in mantleoma differentiation.¹ Histologically, both are benign hamartomas of the pilosebaceous subunit and collectively are known as mantleomas. We present an unusual case of a concomitant fibrofolliculoma and trichodiscoma on the abdomen.

Case Report

An asymptomatic 54-year-old man presented for a routine full-body skin examination. A solitary, 2×1-cm, subcutaneous, doughy, mobile nodule was found on the left side of the abdomen with an overlying 2-mm yellow fleshy papule. The patient declined excision of the lesion, and it was recommended that he return for follow-up 3 months later.

The patient did not present for follow-up until 4.5 years later, at which point the lesion had grown to 3.0×2.5 cm in size. An excision was performed, at which time the lesion was noted to be cystic, extruding an oily, yellow-white liquid. Bacterial culture was negative. Histopathologic sections showed a dome-shaped papule with connection to the overlying epidermis. Epithelial extensions from the infundibular epithelium formed a fenestrated pattern surrounding a fibrous and mucinous stroma (Figure, A and B). The differential diagnosis at this time included an epidermal inclusion cyst, fibroma, intradermal nevus, verruca, hemangioma, angiofibroma, and lipoma.^2-4

The same lesion cut in a different plane of sectioning showed an expansile dermal nodule comprising clusters of sebaceous lobules surrounding a fibrous and mucinous stroma. Within the second lesion, fibrous and stromal components predominated over epithelial components (Figure, C). A diagnosis of fibrofolliculoma showing features of a trichodiscoma arising in the unusual location of the abdomen was made.

Comment

Solitary fibrofolliculomas and trichodiscomas are flesh-colored, dome-shaped papules that generally present on the face, specifically on the chin, nose, cheeks, ears, and eyebrows without considerable symptoms.^2,4,5 Clinically, fibrofolliculomas are indistinguishable from trichodiscomas but demonstrate different features on biopsy.^1,5

Fibrofolliculomas and trichodiscomas are well known for their association with Birt-Hogg-Dubé (BHD) syndrome when they present concomitantly and typically arise earlier in the third decade of life than solitary fibrofolliculomas; however, there have been reports of solitary fibrofolliculomas in patients aged 1 to 36 years.^4,6 The triad of BHD syndrome consists of multiple fibrofolliculomas, trichodiscomas, and acrochordons, and it is acquired in an autosomal-dominant manner, unlike solitary fibrofolliculomas, which typically are not inherited. Birt-Hogg-Dubé syndrome is caused by a mutation in the FLCN gene that codes for the tumor-suppressor protein folliculin, which when mutated can cause unregulated proliferation of cells.⁷ Solitary fibrofolliculomas and the multiple fibrofolliculomas seen in BHD syndrome are histologically similar.

Fibrofolliculoma can be clinically indistinguishable from fibroepithelioma of Pinkus, perifollicular fibroma, trichilemmoma, trichodiscoma, trichoepithelioma, and trichofolliculoma. All typically present clinically as flesh-colored papules,¹ although histologic distinction can be made (Table).^5,8-13

Fibrofolliculoma is a benign hamartoma that arises from the pilosebaceous follicle and consists of an expansion of the fibrous root sheath, which typically surrounds the hair follicle along with proliferating bands or ribbons of perifollicular connective tissue. As such, the hair follicle may be dilated and filled with keratin in the expanded infundibulum.⁸ Follicles also may be surrounded by a myxoid stroma.² In contrast, trichodiscoma is characterized by connective tissue with mature sebaceous lobules in the periphery. It has a myxoid stroma, as opposed to the more fibrous stroma seen in fibrofolliculomas.

Ackerman et al¹ considered both fibrofolliculomas and trichodiscomas to be hamartomas of the epithelial hair follicle. The exact etiology of each of these hamartomas is unknown, but the undifferentiated epithelial strands protruding from the hair follicle in a fibrofolliculoma lie in close proximity to sebaceous glands. Furthermore, the authors postulated that fibrofolliculomas and trichodiscomas constitute a spectrum that encompasses the differentiation process of a mantleoma, with fibrofolliculoma representing the beginning of mantleoma differentiation and trichodiscoma representing the end. This end stage of follicular differentiation is one in which there is a predominant stroma and the previously undifferentiated epithelium has formed into sebaceous ducts and lobules in the stroma.¹

Most cases of fibrofolliculoma and/or trichodiscoma arise in areas of dense sebaceous follicle concentration (eg, face), further supporting the hypothesis that sebaceous gland proliferation contributes to fibrofolliculoma.¹⁴ The case described here, with the fibrofolliculoma arising on the abdomen in conjunction with a trichodiscoma, is therefore worth noting because its location differs from what has been observed in previously reported cases.⁴

There are both surgical and medical options for treatment of fibrofolliculoma. Although surgical excision is an option for a single lesion, patients with multiple fibrofolliculomas or BHD may prefer removal with the combined CO₂ laser and erbium-doped YAG laser.¹⁵

Conclusion

We present a rare case of concomitant fibrofolliculoma and trichodiscoma arising on the unusual location of the abdomen. This report highlights the histopathologic features of multiple adnexal tumors and emphasizes the importance of biopsy for differentiating fibrofolliculoma and trichodiscoma.

Fibrofolliculomas and trichodiscomas typically present on the head or neck as smooth, flesh-colored, dome-shaped papules. These two entities are considered to constitute two separate time points on a spectrum of histopathologic changes in mantleoma differentiation.¹ Histologically, both are benign hamartomas of the pilosebaceous subunit and collectively are known as mantleomas. We present an unusual case of a concomitant fibrofolliculoma and trichodiscoma on the abdomen.

Case Report

An asymptomatic 54-year-old man presented for a routine full-body skin examination. A solitary, 2×1-cm, subcutaneous, doughy, mobile nodule was found on the left side of the abdomen with an overlying 2-mm yellow fleshy papule. The patient declined excision of the lesion, and it was recommended that he return for follow-up 3 months later.

The patient did not present for follow-up until 4.5 years later, at which point the lesion had grown to 3.0×2.5 cm in size. An excision was performed, at which time the lesion was noted to be cystic, extruding an oily, yellow-white liquid. Bacterial culture was negative. Histopathologic sections showed a dome-shaped papule with connection to the overlying epidermis. Epithelial extensions from the infundibular epithelium formed a fenestrated pattern surrounding a fibrous and mucinous stroma (Figure, A and B). The differential diagnosis at this time included an epidermal inclusion cyst, fibroma, intradermal nevus, verruca, hemangioma, angiofibroma, and lipoma.^2-4

The same lesion cut in a different plane of sectioning showed an expansile dermal nodule comprising clusters of sebaceous lobules surrounding a fibrous and mucinous stroma. Within the second lesion, fibrous and stromal components predominated over epithelial components (Figure, C). A diagnosis of fibrofolliculoma showing features of a trichodiscoma arising in the unusual location of the abdomen was made.

Comment

Solitary fibrofolliculomas and trichodiscomas are flesh-colored, dome-shaped papules that generally present on the face, specifically on the chin, nose, cheeks, ears, and eyebrows without considerable symptoms.^2,4,5 Clinically, fibrofolliculomas are indistinguishable from trichodiscomas but demonstrate different features on biopsy.^1,5

Fibrofolliculomas and trichodiscomas are well known for their association with Birt-Hogg-Dubé (BHD) syndrome when they present concomitantly and typically arise earlier in the third decade of life than solitary fibrofolliculomas; however, there have been reports of solitary fibrofolliculomas in patients aged 1 to 36 years.^4,6 The triad of BHD syndrome consists of multiple fibrofolliculomas, trichodiscomas, and acrochordons, and it is acquired in an autosomal-dominant manner, unlike solitary fibrofolliculomas, which typically are not inherited. Birt-Hogg-Dubé syndrome is caused by a mutation in the FLCN gene that codes for the tumor-suppressor protein folliculin, which when mutated can cause unregulated proliferation of cells.⁷ Solitary fibrofolliculomas and the multiple fibrofolliculomas seen in BHD syndrome are histologically similar.

Fibrofolliculoma can be clinically indistinguishable from fibroepithelioma of Pinkus, perifollicular fibroma, trichilemmoma, trichodiscoma, trichoepithelioma, and trichofolliculoma. All typically present clinically as flesh-colored papules,¹ although histologic distinction can be made (Table).^5,8-13

Fibrofolliculoma is a benign hamartoma that arises from the pilosebaceous follicle and consists of an expansion of the fibrous root sheath, which typically surrounds the hair follicle along with proliferating bands or ribbons of perifollicular connective tissue. As such, the hair follicle may be dilated and filled with keratin in the expanded infundibulum.⁸ Follicles also may be surrounded by a myxoid stroma.² In contrast, trichodiscoma is characterized by connective tissue with mature sebaceous lobules in the periphery. It has a myxoid stroma, as opposed to the more fibrous stroma seen in fibrofolliculomas.

Ackerman et al¹ considered both fibrofolliculomas and trichodiscomas to be hamartomas of the epithelial hair follicle. The exact etiology of each of these hamartomas is unknown, but the undifferentiated epithelial strands protruding from the hair follicle in a fibrofolliculoma lie in close proximity to sebaceous glands. Furthermore, the authors postulated that fibrofolliculomas and trichodiscomas constitute a spectrum that encompasses the differentiation process of a mantleoma, with fibrofolliculoma representing the beginning of mantleoma differentiation and trichodiscoma representing the end. This end stage of follicular differentiation is one in which there is a predominant stroma and the previously undifferentiated epithelium has formed into sebaceous ducts and lobules in the stroma.¹

Most cases of fibrofolliculoma and/or trichodiscoma arise in areas of dense sebaceous follicle concentration (eg, face), further supporting the hypothesis that sebaceous gland proliferation contributes to fibrofolliculoma.¹⁴ The case described here, with the fibrofolliculoma arising on the abdomen in conjunction with a trichodiscoma, is therefore worth noting because its location differs from what has been observed in previously reported cases.⁴

There are both surgical and medical options for treatment of fibrofolliculoma. Although surgical excision is an option for a single lesion, patients with multiple fibrofolliculomas or BHD may prefer removal with the combined CO₂ laser and erbium-doped YAG laser.¹⁵

Conclusion

We present a rare case of concomitant fibrofolliculoma and trichodiscoma arising on the unusual location of the abdomen. This report highlights the histopathologic features of multiple adnexal tumors and emphasizes the importance of biopsy for differentiating fibrofolliculoma and trichodiscoma.

Fibrofolliculomas and trichodiscomas typically present on the head or neck as smooth, flesh-colored, dome-shaped papules. These two entities are considered to constitute two separate time points on a spectrum of histopathologic changes in mantleoma differentiation.¹ Histologically, both are benign hamartomas of the pilosebaceous subunit and collectively are known as mantleomas. We present an unusual case of a concomitant fibrofolliculoma and trichodiscoma on the abdomen.

Case Report

An asymptomatic 54-year-old man presented for a routine full-body skin examination. A solitary, 2×1-cm, subcutaneous, doughy, mobile nodule was found on the left side of the abdomen with an overlying 2-mm yellow fleshy papule. The patient declined excision of the lesion, and it was recommended that he return for follow-up 3 months later.

The patient did not present for follow-up until 4.5 years later, at which point the lesion had grown to 3.0×2.5 cm in size. An excision was performed, at which time the lesion was noted to be cystic, extruding an oily, yellow-white liquid. Bacterial culture was negative. Histopathologic sections showed a dome-shaped papule with connection to the overlying epidermis. Epithelial extensions from the infundibular epithelium formed a fenestrated pattern surrounding a fibrous and mucinous stroma (Figure, A and B). The differential diagnosis at this time included an epidermal inclusion cyst, fibroma, intradermal nevus, verruca, hemangioma, angiofibroma, and lipoma.^2-4

The same lesion cut in a different plane of sectioning showed an expansile dermal nodule comprising clusters of sebaceous lobules surrounding a fibrous and mucinous stroma. Within the second lesion, fibrous and stromal components predominated over epithelial components (Figure, C). A diagnosis of fibrofolliculoma showing features of a trichodiscoma arising in the unusual location of the abdomen was made.

Comment

Solitary fibrofolliculomas and trichodiscomas are flesh-colored, dome-shaped papules that generally present on the face, specifically on the chin, nose, cheeks, ears, and eyebrows without considerable symptoms.^2,4,5 Clinically, fibrofolliculomas are indistinguishable from trichodiscomas but demonstrate different features on biopsy.^1,5

Fibrofolliculomas and trichodiscomas are well known for their association with Birt-Hogg-Dubé (BHD) syndrome when they present concomitantly and typically arise earlier in the third decade of life than solitary fibrofolliculomas; however, there have been reports of solitary fibrofolliculomas in patients aged 1 to 36 years.^4,6 The triad of BHD syndrome consists of multiple fibrofolliculomas, trichodiscomas, and acrochordons, and it is acquired in an autosomal-dominant manner, unlike solitary fibrofolliculomas, which typically are not inherited. Birt-Hogg-Dubé syndrome is caused by a mutation in the FLCN gene that codes for the tumor-suppressor protein folliculin, which when mutated can cause unregulated proliferation of cells.⁷ Solitary fibrofolliculomas and the multiple fibrofolliculomas seen in BHD syndrome are histologically similar.

Fibrofolliculoma can be clinically indistinguishable from fibroepithelioma of Pinkus, perifollicular fibroma, trichilemmoma, trichodiscoma, trichoepithelioma, and trichofolliculoma. All typically present clinically as flesh-colored papules,¹ although histologic distinction can be made (Table).^5,8-13

Fibrofolliculoma is a benign hamartoma that arises from the pilosebaceous follicle and consists of an expansion of the fibrous root sheath, which typically surrounds the hair follicle along with proliferating bands or ribbons of perifollicular connective tissue. As such, the hair follicle may be dilated and filled with keratin in the expanded infundibulum.⁸ Follicles also may be surrounded by a myxoid stroma.² In contrast, trichodiscoma is characterized by connective tissue with mature sebaceous lobules in the periphery. It has a myxoid stroma, as opposed to the more fibrous stroma seen in fibrofolliculomas.

Ackerman et al¹ considered both fibrofolliculomas and trichodiscomas to be hamartomas of the epithelial hair follicle. The exact etiology of each of these hamartomas is unknown, but the undifferentiated epithelial strands protruding from the hair follicle in a fibrofolliculoma lie in close proximity to sebaceous glands. Furthermore, the authors postulated that fibrofolliculomas and trichodiscomas constitute a spectrum that encompasses the differentiation process of a mantleoma, with fibrofolliculoma representing the beginning of mantleoma differentiation and trichodiscoma representing the end. This end stage of follicular differentiation is one in which there is a predominant stroma and the previously undifferentiated epithelium has formed into sebaceous ducts and lobules in the stroma.¹

Most cases of fibrofolliculoma and/or trichodiscoma arise in areas of dense sebaceous follicle concentration (eg, face), further supporting the hypothesis that sebaceous gland proliferation contributes to fibrofolliculoma.¹⁴ The case described here, with the fibrofolliculoma arising on the abdomen in conjunction with a trichodiscoma, is therefore worth noting because its location differs from what has been observed in previously reported cases.⁴

There are both surgical and medical options for treatment of fibrofolliculoma. Although surgical excision is an option for a single lesion, patients with multiple fibrofolliculomas or BHD may prefer removal with the combined CO₂ laser and erbium-doped YAG laser.¹⁵

Conclusion

We present a rare case of concomitant fibrofolliculoma and trichodiscoma arising on the unusual location of the abdomen. This report highlights the histopathologic features of multiple adnexal tumors and emphasizes the importance of biopsy for differentiating fibrofolliculoma and trichodiscoma.

Myth: Pick Psoriasis Scales to Remove Them

Patients may be inclined to pick psoriasis scales that appear in noticeable areas or on the scalp. However, they should be counseled to avoid this practice, which could cause an infection. Instead, Dr. Steven Feldman (Winston-Salem, North Carolina) suggests putting on an ointment or oil-like medication to soften the scale. “Almost any kind of moisturizer will change the reflective properties of the scale so that you don’t see the scale,” he advised. He also suggested descaling agents such as topical salicylic acid or lactic acid. His patient education video is available on the American Academy of Dermatology website should you wish to direct your patients to it.

Because salicylic acid is a keratolytic (or peeling agent), it works by causing the outer layer of skin to shed. When applied topically, it helps to soften and lift psoriasis scales. Coal tar over-the-counter products also can be used for the same purpose. The over-the-counter product guide from the National Psoriasis Foundation is a valuable resource to share with patients.

Expert Commentary

I agree that it is very important to treat scale very gently. In addition to risk for infection, picking and traumatizing scale can lead to worsening of the psoriasis. This is known as the Koebner phenomenon. The phenomenon was first described by Heinrich Koebner in 1876 as the formation of psoriatic lesions in uninvolved skin of patients with psoriasis after cutaneous trauma. This isomorphic phenomenon is now known to involve numerous diseases, among them vitiligo, lichen planus, and Darier disease.

—Jeffrey M. Weinberg, MD (New York, New York)

Myth: Pick Psoriasis Scales to Remove Them

Patients may be inclined to pick psoriasis scales that appear in noticeable areas or on the scalp. However, they should be counseled to avoid this practice, which could cause an infection. Instead, Dr. Steven Feldman (Winston-Salem, North Carolina) suggests putting on an ointment or oil-like medication to soften the scale. “Almost any kind of moisturizer will change the reflective properties of the scale so that you don’t see the scale,” he advised. He also suggested descaling agents such as topical salicylic acid or lactic acid. His patient education video is available on the American Academy of Dermatology website should you wish to direct your patients to it.

Because salicylic acid is a keratolytic (or peeling agent), it works by causing the outer layer of skin to shed. When applied topically, it helps to soften and lift psoriasis scales. Coal tar over-the-counter products also can be used for the same purpose. The over-the-counter product guide from the National Psoriasis Foundation is a valuable resource to share with patients.

Expert Commentary

I agree that it is very important to treat scale very gently. In addition to risk for infection, picking and traumatizing scale can lead to worsening of the psoriasis. This is known as the Koebner phenomenon. The phenomenon was first described by Heinrich Koebner in 1876 as the formation of psoriatic lesions in uninvolved skin of patients with psoriasis after cutaneous trauma. This isomorphic phenomenon is now known to involve numerous diseases, among them vitiligo, lichen planus, and Darier disease.

—Jeffrey M. Weinberg, MD (New York, New York)

Myth: Pick Psoriasis Scales to Remove Them

Patients may be inclined to pick psoriasis scales that appear in noticeable areas or on the scalp. However, they should be counseled to avoid this practice, which could cause an infection. Instead, Dr. Steven Feldman (Winston-Salem, North Carolina) suggests putting on an ointment or oil-like medication to soften the scale. “Almost any kind of moisturizer will change the reflective properties of the scale so that you don’t see the scale,” he advised. He also suggested descaling agents such as topical salicylic acid or lactic acid. His patient education video is available on the American Academy of Dermatology website should you wish to direct your patients to it.

Because salicylic acid is a keratolytic (or peeling agent), it works by causing the outer layer of skin to shed. When applied topically, it helps to soften and lift psoriasis scales. Coal tar over-the-counter products also can be used for the same purpose. The over-the-counter product guide from the National Psoriasis Foundation is a valuable resource to share with patients.

Expert Commentary

I agree that it is very important to treat scale very gently. In addition to risk for infection, picking and traumatizing scale can lead to worsening of the psoriasis. This is known as the Koebner phenomenon. The phenomenon was first described by Heinrich Koebner in 1876 as the formation of psoriatic lesions in uninvolved skin of patients with psoriasis after cutaneous trauma. This isomorphic phenomenon is now known to involve numerous diseases, among them vitiligo, lichen planus, and Darier disease.

—Jeffrey M. Weinberg, MD (New York, New York)

To the Editor:

Autoimmune progesterone dermatitis (APD) is a rare dermatologic condition that can be challenging to diagnose. The associated skin lesions are not only variable in physical presentation but also in the timing of the outbreak. The skin disorder stems from an internal reaction to elevated levels of progesterone during the luteal phase of the menstrual cycle. Autoimmune progesterone dermatitis can be difficult to detect; although the typical menstrual cycle is 28 days, many women have longer or shorter hormonal phases, leading to cyclical irregularity that can cause the lesions to appear sporadic in nature when in fact they are not.¹

A 34-year-old woman with a history of endometriosis, psoriasis, and malignant melanoma presented to our dermatology clinic 2 days after a brief hospitalization during which she was diagnosed with a hypersensitivity reaction. Two days prior to her hospital admission, the patient developed a rash on the lower back with associated myalgia. The rash progressively worsened, spreading laterally to the flanks, which prompted her to seek medical attention. Blood work included a complete blood cell count with differential, complete metabolic panel, antinuclear antibody test, and erythrocyte sedimentation rate, which all were within reference range. A 4-mm punch biopsy from the left lateral flank was performed and was consistent with a neutrophilic dermatosis. The patient’s symptoms diminished and she was discharged the next day with instructions to follow up with a dermatologist.

Physical examination at our clinic revealed multiple minimally indurated, erythematous plaques with superficial scaling along the left lower back and upper buttock (Figure 1). No other skin lesions were present, and palpation of the cervical, axillary, and inguinal lymph nodes was unremarkable. A repeat 6-mm punch biopsy was performed and she was sent for fasting blood work.

Histologic examination of the punch biopsy revealed a superficial and deep perivascular and interstitial dermatitis with scattered neutrophils and eosinophils. Findings were described as nonspecific, possibly representing a dermal hypersensitivity or urticarial reaction.

Glucose-6-phosphate dehydrogenase testing was within reference range, and therapy was initiated with oral dapsone 50 mg once daily as well as fexofenadine 180 mg once daily. The patient initially responded well to the oral therapy, but she experienced recurrence of the skin eruption at infrequent intervals over the next few months, requiring escalating doses of dapsone to control the symptoms. After further questioning at a subsequent visit a few months later, it was discovered that the eruption occurred near the onset of the patient’s irregular menstrual cycle.

Approximately 1 year after her initial presentation, the patient returned for intradermal hormone injections to test for hormonally induced hypersensitivities. An injection of0.1 mL of a 50-mg/mL progesterone solution was administered in the right forearm as well as 0.1 mL of a 5-mg/mL estradiol solution and 0.1 mL of saline in the left forearm as a control. One hour after the injections, a strong positive reaction consisting of a 15-mm indurated plaque with surrounding wheal was noted at the site of the progesterone injection. The estradiol and saline control sites were clear of any dermal reaction (Figure 2). A diagnosis of APD was established, and the patient was referred to her gynecologist for treatment.

Due to the aggressive nature of her endometriosis, the gonadotropin-releasing hormone agonist leuprolide acetate was the first-line treatment prescribed by her gynecologist; however, after 8 months of therapy with leuprolide acetate, she was still experiencing breakthrough myalgia with her menstrual cycle and opted for a hysterectomy with a bilateral salpingo-oophorectomy. Within weeks of surgery, the myalgia ceased and the patient was completely asymptomatic.

Autoimmune progesterone dermatitis was first described in 1921.² In affected women, the body reacts to the progesterone hormone surge during the luteal phase of the menstrual cycle. Symptoms begin approximately 3 to 4 days prior to menses and resolve 2 to 3 days after onset of flow. These progesterone hypersensitivity reactions can present within a spectrum of morphologies and severities. The lesions can appear eczematous, urticarial, as an angioedemalike reaction, as an erythema multiforme–like reaction with targetoid lesions, or in other nonspecific ways.^1,3 Some patients experience a very mild, almost asymptomatic reaction, while others have a profound reaction progressing to anaphylaxis. Originally it was thought that exogenous exposure to progesterone led to a cross-reaction or hypersensitivity to the hormone; however, there have been cases reported in females as young as 12 years of age with no prior exposure.^3,4 Reactions also can vary during pregnancy. There have been reports of spontaneous abortion in some affected females, but symptoms may dissipate in others, possibly due to a slow rise in progesterone causing a desensitization reaction.^3,5

According to Bandino et al,⁶ there are 3 criteria for diagnosis of APD: (1) skin lesions related to the menstrual cycle, (2) positive response to intradermal testing with progesterone, and (3) symptomatic improvement after inhibiting progesterone secretions by suppressing ovulation.Areas checked with intradermal testing need to be evaluated 24 and 48 hours later for possible immediate or delayed-type hypersensitivity reactions. Biopsy typically is not helpful in this diagnosis because results usually are nonspecific.

Treatment of APD is targeted toward suppressing the internal hormonal surge. By suppressing the progesterone hormone, the symptoms are alleviated. The discomfort from the skin reaction typically is unresponsive to steroids or antihistamines. Oral contraceptives are first line in most cases because they suppress ovulation. Gonadotropin-releasing hormone analogues and tamoxifen also have been successful. For patients with severe disease that is recalcitrant to standard therapy or those who are postmenopausal, an oophorectemy is a curative option.^2,4,5,7

Autoimmune progesterone dermatitis is a rare cyclical dermatologic condition in which the body responds to a surge of the patient’s own progesterone hormone. The disorder is difficult to diagnose because it can present with differing morphologies and biopsy is nonspecific. It also can be increasingly difficult to diagnose in women who do not have a typical 28-day menstrual cycle. In our patient, her irregular menstrual cycle may have caused a delay in diagnosis. Although the condition is rare, APD should be included in the differential diagnosis in females with a recurrent, cyclical, or recalcitrant cutaneous eruption.

To the Editor:

Autoimmune progesterone dermatitis (APD) is a rare dermatologic condition that can be challenging to diagnose. The associated skin lesions are not only variable in physical presentation but also in the timing of the outbreak. The skin disorder stems from an internal reaction to elevated levels of progesterone during the luteal phase of the menstrual cycle. Autoimmune progesterone dermatitis can be difficult to detect; although the typical menstrual cycle is 28 days, many women have longer or shorter hormonal phases, leading to cyclical irregularity that can cause the lesions to appear sporadic in nature when in fact they are not.¹

A 34-year-old woman with a history of endometriosis, psoriasis, and malignant melanoma presented to our dermatology clinic 2 days after a brief hospitalization during which she was diagnosed with a hypersensitivity reaction. Two days prior to her hospital admission, the patient developed a rash on the lower back with associated myalgia. The rash progressively worsened, spreading laterally to the flanks, which prompted her to seek medical attention. Blood work included a complete blood cell count with differential, complete metabolic panel, antinuclear antibody test, and erythrocyte sedimentation rate, which all were within reference range. A 4-mm punch biopsy from the left lateral flank was performed and was consistent with a neutrophilic dermatosis. The patient’s symptoms diminished and she was discharged the next day with instructions to follow up with a dermatologist.

Physical examination at our clinic revealed multiple minimally indurated, erythematous plaques with superficial scaling along the left lower back and upper buttock (Figure 1). No other skin lesions were present, and palpation of the cervical, axillary, and inguinal lymph nodes was unremarkable. A repeat 6-mm punch biopsy was performed and she was sent for fasting blood work.

Histologic examination of the punch biopsy revealed a superficial and deep perivascular and interstitial dermatitis with scattered neutrophils and eosinophils. Findings were described as nonspecific, possibly representing a dermal hypersensitivity or urticarial reaction.

Glucose-6-phosphate dehydrogenase testing was within reference range, and therapy was initiated with oral dapsone 50 mg once daily as well as fexofenadine 180 mg once daily. The patient initially responded well to the oral therapy, but she experienced recurrence of the skin eruption at infrequent intervals over the next few months, requiring escalating doses of dapsone to control the symptoms. After further questioning at a subsequent visit a few months later, it was discovered that the eruption occurred near the onset of the patient’s irregular menstrual cycle.

Approximately 1 year after her initial presentation, the patient returned for intradermal hormone injections to test for hormonally induced hypersensitivities. An injection of0.1 mL of a 50-mg/mL progesterone solution was administered in the right forearm as well as 0.1 mL of a 5-mg/mL estradiol solution and 0.1 mL of saline in the left forearm as a control. One hour after the injections, a strong positive reaction consisting of a 15-mm indurated plaque with surrounding wheal was noted at the site of the progesterone injection. The estradiol and saline control sites were clear of any dermal reaction (Figure 2). A diagnosis of APD was established, and the patient was referred to her gynecologist for treatment.

Due to the aggressive nature of her endometriosis, the gonadotropin-releasing hormone agonist leuprolide acetate was the first-line treatment prescribed by her gynecologist; however, after 8 months of therapy with leuprolide acetate, she was still experiencing breakthrough myalgia with her menstrual cycle and opted for a hysterectomy with a bilateral salpingo-oophorectomy. Within weeks of surgery, the myalgia ceased and the patient was completely asymptomatic.

Autoimmune progesterone dermatitis was first described in 1921.² In affected women, the body reacts to the progesterone hormone surge during the luteal phase of the menstrual cycle. Symptoms begin approximately 3 to 4 days prior to menses and resolve 2 to 3 days after onset of flow. These progesterone hypersensitivity reactions can present within a spectrum of morphologies and severities. The lesions can appear eczematous, urticarial, as an angioedemalike reaction, as an erythema multiforme–like reaction with targetoid lesions, or in other nonspecific ways.^1,3 Some patients experience a very mild, almost asymptomatic reaction, while others have a profound reaction progressing to anaphylaxis. Originally it was thought that exogenous exposure to progesterone led to a cross-reaction or hypersensitivity to the hormone; however, there have been cases reported in females as young as 12 years of age with no prior exposure.^3,4 Reactions also can vary during pregnancy. There have been reports of spontaneous abortion in some affected females, but symptoms may dissipate in others, possibly due to a slow rise in progesterone causing a desensitization reaction.^3,5

According to Bandino et al,⁶ there are 3 criteria for diagnosis of APD: (1) skin lesions related to the menstrual cycle, (2) positive response to intradermal testing with progesterone, and (3) symptomatic improvement after inhibiting progesterone secretions by suppressing ovulation.Areas checked with intradermal testing need to be evaluated 24 and 48 hours later for possible immediate or delayed-type hypersensitivity reactions. Biopsy typically is not helpful in this diagnosis because results usually are nonspecific.

Treatment of APD is targeted toward suppressing the internal hormonal surge. By suppressing the progesterone hormone, the symptoms are alleviated. The discomfort from the skin reaction typically is unresponsive to steroids or antihistamines. Oral contraceptives are first line in most cases because they suppress ovulation. Gonadotropin-releasing hormone analogues and tamoxifen also have been successful. For patients with severe disease that is recalcitrant to standard therapy or those who are postmenopausal, an oophorectemy is a curative option.^2,4,5,7

Autoimmune progesterone dermatitis is a rare cyclical dermatologic condition in which the body responds to a surge of the patient’s own progesterone hormone. The disorder is difficult to diagnose because it can present with differing morphologies and biopsy is nonspecific. It also can be increasingly difficult to diagnose in women who do not have a typical 28-day menstrual cycle. In our patient, her irregular menstrual cycle may have caused a delay in diagnosis. Although the condition is rare, APD should be included in the differential diagnosis in females with a recurrent, cyclical, or recalcitrant cutaneous eruption.

To the Editor:

Autoimmune progesterone dermatitis (APD) is a rare dermatologic condition that can be challenging to diagnose. The associated skin lesions are not only variable in physical presentation but also in the timing of the outbreak. The skin disorder stems from an internal reaction to elevated levels of progesterone during the luteal phase of the menstrual cycle. Autoimmune progesterone dermatitis can be difficult to detect; although the typical menstrual cycle is 28 days, many women have longer or shorter hormonal phases, leading to cyclical irregularity that can cause the lesions to appear sporadic in nature when in fact they are not.¹

A 34-year-old woman with a history of endometriosis, psoriasis, and malignant melanoma presented to our dermatology clinic 2 days after a brief hospitalization during which she was diagnosed with a hypersensitivity reaction. Two days prior to her hospital admission, the patient developed a rash on the lower back with associated myalgia. The rash progressively worsened, spreading laterally to the flanks, which prompted her to seek medical attention. Blood work included a complete blood cell count with differential, complete metabolic panel, antinuclear antibody test, and erythrocyte sedimentation rate, which all were within reference range. A 4-mm punch biopsy from the left lateral flank was performed and was consistent with a neutrophilic dermatosis. The patient’s symptoms diminished and she was discharged the next day with instructions to follow up with a dermatologist.

Physical examination at our clinic revealed multiple minimally indurated, erythematous plaques with superficial scaling along the left lower back and upper buttock (Figure 1). No other skin lesions were present, and palpation of the cervical, axillary, and inguinal lymph nodes was unremarkable. A repeat 6-mm punch biopsy was performed and she was sent for fasting blood work.

Histologic examination of the punch biopsy revealed a superficial and deep perivascular and interstitial dermatitis with scattered neutrophils and eosinophils. Findings were described as nonspecific, possibly representing a dermal hypersensitivity or urticarial reaction.

Glucose-6-phosphate dehydrogenase testing was within reference range, and therapy was initiated with oral dapsone 50 mg once daily as well as fexofenadine 180 mg once daily. The patient initially responded well to the oral therapy, but she experienced recurrence of the skin eruption at infrequent intervals over the next few months, requiring escalating doses of dapsone to control the symptoms. After further questioning at a subsequent visit a few months later, it was discovered that the eruption occurred near the onset of the patient’s irregular menstrual cycle.

Approximately 1 year after her initial presentation, the patient returned for intradermal hormone injections to test for hormonally induced hypersensitivities. An injection of0.1 mL of a 50-mg/mL progesterone solution was administered in the right forearm as well as 0.1 mL of a 5-mg/mL estradiol solution and 0.1 mL of saline in the left forearm as a control. One hour after the injections, a strong positive reaction consisting of a 15-mm indurated plaque with surrounding wheal was noted at the site of the progesterone injection. The estradiol and saline control sites were clear of any dermal reaction (Figure 2). A diagnosis of APD was established, and the patient was referred to her gynecologist for treatment.

Due to the aggressive nature of her endometriosis, the gonadotropin-releasing hormone agonist leuprolide acetate was the first-line treatment prescribed by her gynecologist; however, after 8 months of therapy with leuprolide acetate, she was still experiencing breakthrough myalgia with her menstrual cycle and opted for a hysterectomy with a bilateral salpingo-oophorectomy. Within weeks of surgery, the myalgia ceased and the patient was completely asymptomatic.

Autoimmune progesterone dermatitis was first described in 1921.² In affected women, the body reacts to the progesterone hormone surge during the luteal phase of the menstrual cycle. Symptoms begin approximately 3 to 4 days prior to menses and resolve 2 to 3 days after onset of flow. These progesterone hypersensitivity reactions can present within a spectrum of morphologies and severities. The lesions can appear eczematous, urticarial, as an angioedemalike reaction, as an erythema multiforme–like reaction with targetoid lesions, or in other nonspecific ways.^1,3 Some patients experience a very mild, almost asymptomatic reaction, while others have a profound reaction progressing to anaphylaxis. Originally it was thought that exogenous exposure to progesterone led to a cross-reaction or hypersensitivity to the hormone; however, there have been cases reported in females as young as 12 years of age with no prior exposure.^3,4 Reactions also can vary during pregnancy. There have been reports of spontaneous abortion in some affected females, but symptoms may dissipate in others, possibly due to a slow rise in progesterone causing a desensitization reaction.^3,5

According to Bandino et al,⁶ there are 3 criteria for diagnosis of APD: (1) skin lesions related to the menstrual cycle, (2) positive response to intradermal testing with progesterone, and (3) symptomatic improvement after inhibiting progesterone secretions by suppressing ovulation.Areas checked with intradermal testing need to be evaluated 24 and 48 hours later for possible immediate or delayed-type hypersensitivity reactions. Biopsy typically is not helpful in this diagnosis because results usually are nonspecific.

Treatment of APD is targeted toward suppressing the internal hormonal surge. By suppressing the progesterone hormone, the symptoms are alleviated. The discomfort from the skin reaction typically is unresponsive to steroids or antihistamines. Oral contraceptives are first line in most cases because they suppress ovulation. Gonadotropin-releasing hormone analogues and tamoxifen also have been successful. For patients with severe disease that is recalcitrant to standard therapy or those who are postmenopausal, an oophorectemy is a curative option.^2,4,5,7

Autoimmune progesterone dermatitis is a rare cyclical dermatologic condition in which the body responds to a surge of the patient’s own progesterone hormone. The disorder is difficult to diagnose because it can present with differing morphologies and biopsy is nonspecific. It also can be increasingly difficult to diagnose in women who do not have a typical 28-day menstrual cycle. In our patient, her irregular menstrual cycle may have caused a delay in diagnosis. Although the condition is rare, APD should be included in the differential diagnosis in females with a recurrent, cyclical, or recalcitrant cutaneous eruption.