Photo Challenge

The Diagnosis: Persistent Still Disease

At the time of presentation, the patient had not taken systemic medications for a year. Laboratory studies revealed leukocytosis with neutrophilia and a serum ferritin level of 5493 ng/mL (reference range, 15-200 ng/mL). Rheumatoid factor and antinuclear antibody serologies were within reference range. Microbiologic workup was negative. Lymph node and bone marrow biopsies were negative for a lymphoproliferative disorder. Skin biopsies were performed on the back and forearm. Histologic evaluation revealed orthokeratosis, slight acanthosis, and dyskeratosis confined to the upper layers of the epidermis without evidence of interface dermatitis. There was a mixed perivascular infiltrate composed of lymphocytes and neutrophils with no attendant vasculitic change (Figure).

The patient was discharged on prednisone and seen for outpatient follow-up weeks later. Six weeks later, the cutaneous eruption remained unchanged. The patient was unable to start other systemic medications due to lack of insurance and ineligibility for the local patient-assistance program; he was subsequently lost to follow-up. 

Adult-onset Still disease is a rare, systemic, inflammatory condition with a broad spectrum of clinical presentations.^1-3 Still disease affects all age groups, and children with Still disease (<16 years) usually have a concurrent diagnosis of juvenile idiopathic arthritis (formerly known as juvenile rheumatoid arthritis).^1,2,4 Still disease preferentially affects adolescents and adults aged 16 to 35 years, with more than 75% of new cases occurring in this age range.¹ Worldwide, the incidence and prevalence of Still disease is disputed with no conclusive rates established.^1,3

Still disease is characterized by 4 cardinal signs: high spiking fevers (temperature, ≥39°C); leukocytosis with a predominance of neutrophils (≥10,000 cells/mm³ with ≥80% neutrophils); arthralgia or arthritis; and an evanescent, nonpruritic, salmon-colored morbilliform eruption of the skin, typically on the trunk or extremities.² Histologic evaluation of the classic Still disease eruption displays perivascular inflammation of the superficial dermis with infiltration by lymphocytes and histiocytes.³

In 1992, major and minor diagnostic criteria were established for adult-onset Still disease. For diagnosis, patients must meet 5 criteria, including 2 major criteria.⁵ Major criteria include arthralgia or arthritis present for more than 2 weeks, fever (temperature, >39°C) for at least 1 week, the classic Still disease morbilliform eruption (ie, salmon colored, evanescent, morbilliform), and leukocytosis with more than 80% neutrophils. Minor criteria include sore throat, lymphadenopathy and/or splenomegaly, negative rheumatoid factor and antinuclear antibody serologies, and abnormal liver function (defined as elevated transaminases).⁵ Although not included in the diagnostic criteria, there have been reports of elevated serum ferritin levels in patients with Still disease, a finding that potentially is useful in distinguishing between active and inactive rheumatic conditions.^6,7

Several case reports have described persistent Still disease, a subtype of Still disease in which patients present with brown-red, persistent, pruritic macules, papules, and plaques that are widespread and oddly shaped.^8,9 Histologically, this subtype is characterized by necrotic keratinocytes in the epidermis and dermal perivascular inflammation composed of neutrophils and lymphocytes.¹⁰ This histology differs from classic Still disease in that the latter typically does not have superficial epidermal dyskeratosis. Our case is consistent with reports of persistent Still disease.

Although the etiology of Still disease remains to be elucidated, HLA-B17, -B18, -B35, and -DR2 have been associated with the disease.³ Furthermore, helper T cell T_H1, IL-2, IFN-γ, and tumor necrosis factor α have been implicated in disease pathology, enabling the use of newer targeted pharmacologic therapies. Canakinumab, an IL-1β inhibitor, has been found to improve arthritis, fever, and rash in patients with Still disease.¹¹ These findings are particularly encouraging for patients who have not experienced improvement with traditional antirheumatic drugs, such as our patient who was not steroid responsive.³

Although a salmon-colored, evanescent, morbilliform eruption in the context of other systemic signs and symptoms readily evokes consideration of Still disease, the less common fixed cutaneous eruption seen in our case may evade accurate diagnosis. Our case aims to increase awareness of this unusual and rare subtype of the cutaneous eruption of Still disease, as a timely diagnosis may prevent potentially life-threatening sequelae including cardiopulmonary disease and respiratory failure.^3,5,9

The Diagnosis: Persistent Still Disease

At the time of presentation, the patient had not taken systemic medications for a year. Laboratory studies revealed leukocytosis with neutrophilia and a serum ferritin level of 5493 ng/mL (reference range, 15-200 ng/mL). Rheumatoid factor and antinuclear antibody serologies were within reference range. Microbiologic workup was negative. Lymph node and bone marrow biopsies were negative for a lymphoproliferative disorder. Skin biopsies were performed on the back and forearm. Histologic evaluation revealed orthokeratosis, slight acanthosis, and dyskeratosis confined to the upper layers of the epidermis without evidence of interface dermatitis. There was a mixed perivascular infiltrate composed of lymphocytes and neutrophils with no attendant vasculitic change (Figure).

The patient was discharged on prednisone and seen for outpatient follow-up weeks later. Six weeks later, the cutaneous eruption remained unchanged. The patient was unable to start other systemic medications due to lack of insurance and ineligibility for the local patient-assistance program; he was subsequently lost to follow-up. 

Adult-onset Still disease is a rare, systemic, inflammatory condition with a broad spectrum of clinical presentations.^1-3 Still disease affects all age groups, and children with Still disease (<16 years) usually have a concurrent diagnosis of juvenile idiopathic arthritis (formerly known as juvenile rheumatoid arthritis).^1,2,4 Still disease preferentially affects adolescents and adults aged 16 to 35 years, with more than 75% of new cases occurring in this age range.¹ Worldwide, the incidence and prevalence of Still disease is disputed with no conclusive rates established.^1,3

Still disease is characterized by 4 cardinal signs: high spiking fevers (temperature, ≥39°C); leukocytosis with a predominance of neutrophils (≥10,000 cells/mm³ with ≥80% neutrophils); arthralgia or arthritis; and an evanescent, nonpruritic, salmon-colored morbilliform eruption of the skin, typically on the trunk or extremities.² Histologic evaluation of the classic Still disease eruption displays perivascular inflammation of the superficial dermis with infiltration by lymphocytes and histiocytes.³

In 1992, major and minor diagnostic criteria were established for adult-onset Still disease. For diagnosis, patients must meet 5 criteria, including 2 major criteria.⁵ Major criteria include arthralgia or arthritis present for more than 2 weeks, fever (temperature, >39°C) for at least 1 week, the classic Still disease morbilliform eruption (ie, salmon colored, evanescent, morbilliform), and leukocytosis with more than 80% neutrophils. Minor criteria include sore throat, lymphadenopathy and/or splenomegaly, negative rheumatoid factor and antinuclear antibody serologies, and abnormal liver function (defined as elevated transaminases).⁵ Although not included in the diagnostic criteria, there have been reports of elevated serum ferritin levels in patients with Still disease, a finding that potentially is useful in distinguishing between active and inactive rheumatic conditions.^6,7

Several case reports have described persistent Still disease, a subtype of Still disease in which patients present with brown-red, persistent, pruritic macules, papules, and plaques that are widespread and oddly shaped.^8,9 Histologically, this subtype is characterized by necrotic keratinocytes in the epidermis and dermal perivascular inflammation composed of neutrophils and lymphocytes.¹⁰ This histology differs from classic Still disease in that the latter typically does not have superficial epidermal dyskeratosis. Our case is consistent with reports of persistent Still disease.

Although the etiology of Still disease remains to be elucidated, HLA-B17, -B18, -B35, and -DR2 have been associated with the disease.³ Furthermore, helper T cell T_H1, IL-2, IFN-γ, and tumor necrosis factor α have been implicated in disease pathology, enabling the use of newer targeted pharmacologic therapies. Canakinumab, an IL-1β inhibitor, has been found to improve arthritis, fever, and rash in patients with Still disease.¹¹ These findings are particularly encouraging for patients who have not experienced improvement with traditional antirheumatic drugs, such as our patient who was not steroid responsive.³

Although a salmon-colored, evanescent, morbilliform eruption in the context of other systemic signs and symptoms readily evokes consideration of Still disease, the less common fixed cutaneous eruption seen in our case may evade accurate diagnosis. Our case aims to increase awareness of this unusual and rare subtype of the cutaneous eruption of Still disease, as a timely diagnosis may prevent potentially life-threatening sequelae including cardiopulmonary disease and respiratory failure.^3,5,9

The Diagnosis: Persistent Still Disease

At the time of presentation, the patient had not taken systemic medications for a year. Laboratory studies revealed leukocytosis with neutrophilia and a serum ferritin level of 5493 ng/mL (reference range, 15-200 ng/mL). Rheumatoid factor and antinuclear antibody serologies were within reference range. Microbiologic workup was negative. Lymph node and bone marrow biopsies were negative for a lymphoproliferative disorder. Skin biopsies were performed on the back and forearm. Histologic evaluation revealed orthokeratosis, slight acanthosis, and dyskeratosis confined to the upper layers of the epidermis without evidence of interface dermatitis. There was a mixed perivascular infiltrate composed of lymphocytes and neutrophils with no attendant vasculitic change (Figure).

The patient was discharged on prednisone and seen for outpatient follow-up weeks later. Six weeks later, the cutaneous eruption remained unchanged. The patient was unable to start other systemic medications due to lack of insurance and ineligibility for the local patient-assistance program; he was subsequently lost to follow-up. 

Adult-onset Still disease is a rare, systemic, inflammatory condition with a broad spectrum of clinical presentations.^1-3 Still disease affects all age groups, and children with Still disease (<16 years) usually have a concurrent diagnosis of juvenile idiopathic arthritis (formerly known as juvenile rheumatoid arthritis).^1,2,4 Still disease preferentially affects adolescents and adults aged 16 to 35 years, with more than 75% of new cases occurring in this age range.¹ Worldwide, the incidence and prevalence of Still disease is disputed with no conclusive rates established.^1,3

Still disease is characterized by 4 cardinal signs: high spiking fevers (temperature, ≥39°C); leukocytosis with a predominance of neutrophils (≥10,000 cells/mm³ with ≥80% neutrophils); arthralgia or arthritis; and an evanescent, nonpruritic, salmon-colored morbilliform eruption of the skin, typically on the trunk or extremities.² Histologic evaluation of the classic Still disease eruption displays perivascular inflammation of the superficial dermis with infiltration by lymphocytes and histiocytes.³

In 1992, major and minor diagnostic criteria were established for adult-onset Still disease. For diagnosis, patients must meet 5 criteria, including 2 major criteria.⁵ Major criteria include arthralgia or arthritis present for more than 2 weeks, fever (temperature, >39°C) for at least 1 week, the classic Still disease morbilliform eruption (ie, salmon colored, evanescent, morbilliform), and leukocytosis with more than 80% neutrophils. Minor criteria include sore throat, lymphadenopathy and/or splenomegaly, negative rheumatoid factor and antinuclear antibody serologies, and abnormal liver function (defined as elevated transaminases).⁵ Although not included in the diagnostic criteria, there have been reports of elevated serum ferritin levels in patients with Still disease, a finding that potentially is useful in distinguishing between active and inactive rheumatic conditions.^6,7

Several case reports have described persistent Still disease, a subtype of Still disease in which patients present with brown-red, persistent, pruritic macules, papules, and plaques that are widespread and oddly shaped.^8,9 Histologically, this subtype is characterized by necrotic keratinocytes in the epidermis and dermal perivascular inflammation composed of neutrophils and lymphocytes.¹⁰ This histology differs from classic Still disease in that the latter typically does not have superficial epidermal dyskeratosis. Our case is consistent with reports of persistent Still disease.

Although the etiology of Still disease remains to be elucidated, HLA-B17, -B18, -B35, and -DR2 have been associated with the disease.³ Furthermore, helper T cell T_H1, IL-2, IFN-γ, and tumor necrosis factor α have been implicated in disease pathology, enabling the use of newer targeted pharmacologic therapies. Canakinumab, an IL-1β inhibitor, has been found to improve arthritis, fever, and rash in patients with Still disease.¹¹ These findings are particularly encouraging for patients who have not experienced improvement with traditional antirheumatic drugs, such as our patient who was not steroid responsive.³

Although a salmon-colored, evanescent, morbilliform eruption in the context of other systemic signs and symptoms readily evokes consideration of Still disease, the less common fixed cutaneous eruption seen in our case may evade accurate diagnosis. Our case aims to increase awareness of this unusual and rare subtype of the cutaneous eruption of Still disease, as a timely diagnosis may prevent potentially life-threatening sequelae including cardiopulmonary disease and respiratory failure.^3,5,9

The Diagnosis: Allergic Contact Dermatitis

An allergic contact dermatitis (ACD) to acrylates was suspected and 4 patches were applied to the forearm (the North American Standard Series of the North American Contact Dermatitis Group). The patches were 2-hydroxyethyl methacrylate (2-HEMA) 2.0% permissible exposure limit (peL), ethyl acrylate 0.1% peL, tosylamide formaldehyde resin 10.0% peL, and methyl methacrylate 2.0% peL. A reading at 72 hours was performed and showed a positive reaction to hydroxyethyl methacrylate, ethyl acrylate, and methyl methacrylate, and a negative patch test to tosylamide formaldehyde resin (nail polish)(Figure). The patient was diagnosed with an allergic contact hypersensitivity to the aforementioned acrylates and instructed to avoid artificial nails and acrylate glues. She also was started on oral biotin supplements. On 6-month follow-up the patient had regrowth of all 10 fingernails without brittleness or splitting. She was able to use nail polishes but avoided all acrylic artificial nails and acrylate-containing personal care products.

Acrylate Allergy and Artificial Nails

Acrylates are plastic materials formed by polymerization of acrylic or methacrylic acid monomers and have been cited as a major cause of occupational and nonoccupational contact dermatitis. Contact dermatitis to acrylates in artificial nails was first reported in the 1950s.^1,2 Products containing 100% methyl methacrylate monomers in acrylic nails were banned by the US Food and Drug Administration in the early 1970s after receiving a number of complaints.³ However, no regulation prohibits the use of methyl methacrylate monomer in cosmetic products, and various methacrylate and acrylate monomers remain widely used.⁴ With a growing popularity in artificial nails, it is expected the number of sensitized persons will increase.

Acrylate allergy from sculptured nails concern self-curing resins made from a polymer powder and a liquid monomer solution. Advantages of new UV-cured products include the lack of unpleasant smell and simplified modeling. They also do not require an irritant, such as methacrylic acid, as a bonding agent. Instead, 2-HEMA and 2-hydroxypropyl methacrylate are added. These photobonded nails colloquially are called gel nails (acid free) as opposed to acrylic nails (using methacrylic acid as a primer). It is important to note that the esters of acrylic acid but not the acid itself sensitize patients, and sensitization is not caused by the uncured gel or the monomer solution but by the remaining monomers in the cured plastic nail and the dust filings that are produced during the finishing process.

Clinical Presentation

Symptoms of an ACD to nail acrylates include pruritus and fingertip dermatitis along with nail plate dystrophy. There may be pruritus at the nail base, with subsequent dryness, thickening, and onycholysis. The brittle nails may become split, discolored, and develop paronychia. Inadvertent contact with glue monomers or other acrylate-containing substances may cause eczematous lesions at distant sites. Avoidance of the allergen often results in complete restoration of the normal nail and fingertip within months.

Sensitization

Acrylates and methacrylates are ubiquitous materials used for both industrial and commercial applications. Due to their widespread industrial use, contact allergies to acrylates including 2-HEMA, 2-hydroxypropyl methacrylate, and triethyleneglycol diacrylate (TREGDA) are common. Cross-reaction of these compounds has been observed and is postulated to be due to reaction of the (meth)acrylate carboxyethyl group with the receptors of antigen-presenting cells.⁵ As a result, an individual with an acrylate allergy sensitized to one allergen often is allergic to its similar compounds and cross-reactors and must avoid the assortment of compounds containing these ingredients, which is important for individuals with occupational sensitization to a particular acrylate who is subsequently susceptible to other acrylate-containing compounds triggering allergic reactions when reexposure occurs in different settings.

Allergens and Occupational Exposure

Acrylates in cosmetic nail products are a source of ACD for not only the customer but also the manicurist.⁶ The most frequently cited sources of ACD in beauticians are acrylate chemicals.⁷ However, acrylate compounds are an occupational hazard for a number of other specialists, including dentists and dental technicians, histology technicians, and individuals in the printing industry.^8,9 Other individuals may be sensitized to acrylates through their inclusion in adhesives, dental bonding agents, hearing aids, electrocardiogram electrodes, artificial bone cement, and a myriad of other medical and nonmedical applications.^4,10-12 For workers who cannot avoid occupational exposure to these allergens, polyvinyl alcohol and multilayer laminate gloves are recommended, as natural rubber latex gloves do not always provide adequate protection from many of these agents.¹⁰

Testing for Suspected Acrylate Allergy

Cross-reactivity among acrylates is widely considered in the literature but remains enigmatic and is an important consideration with regard to routine patch test screening.¹³ In the case of an acrylate allergy to nail products, using 2-HEMA and ethylene glycol dimethacrylate is effective in detecting sensitization by photobonded nails and in patients sensitized by powder liquid products.¹⁴ One study showed a patch test panel including 2-HEMA, ethylene glycol dimethacrylate, and TREGDA was effective in identifying the majority of individuals with an allergy to acrylates in nail products and nail technicians.¹⁵ Another study has shown the most commonly positive testing allergens to be HEMA, ethyl acrylate, and methyl methacrylate.¹⁶ If one is patch testing only one chemical, it appears 2-HEMA is preferred.¹⁷ However, broader panels of screening allergens are necessary to achieve an accurate diagnosis. Furthermore, different panels of test allergens have been shown to vary in their ability to detect an acrylate allergy in different occupational exposures.¹² 

The time to patch test read also is important. A standard read at 72 hours is warranted; however, one study showed if only one read at day 3 was done without a subsequent day 7 read, then 25% of TREGDA and 50% of 2-HEMA allergies would have been missed in patients with occupational acrylate allergy.¹⁵ Other studies have reported late-appearing and long-lasting test reactions when testing for an acrylate allergy.^18,19 Clinicians should be cognizant that an acrylate allergy may be present even if initial screening is negative but the history and clinical picture are suggestive.

The Diagnosis: Allergic Contact Dermatitis

An allergic contact dermatitis (ACD) to acrylates was suspected and 4 patches were applied to the forearm (the North American Standard Series of the North American Contact Dermatitis Group). The patches were 2-hydroxyethyl methacrylate (2-HEMA) 2.0% permissible exposure limit (peL), ethyl acrylate 0.1% peL, tosylamide formaldehyde resin 10.0% peL, and methyl methacrylate 2.0% peL. A reading at 72 hours was performed and showed a positive reaction to hydroxyethyl methacrylate, ethyl acrylate, and methyl methacrylate, and a negative patch test to tosylamide formaldehyde resin (nail polish)(Figure). The patient was diagnosed with an allergic contact hypersensitivity to the aforementioned acrylates and instructed to avoid artificial nails and acrylate glues. She also was started on oral biotin supplements. On 6-month follow-up the patient had regrowth of all 10 fingernails without brittleness or splitting. She was able to use nail polishes but avoided all acrylic artificial nails and acrylate-containing personal care products.

Acrylate Allergy and Artificial Nails

Acrylates are plastic materials formed by polymerization of acrylic or methacrylic acid monomers and have been cited as a major cause of occupational and nonoccupational contact dermatitis. Contact dermatitis to acrylates in artificial nails was first reported in the 1950s.^1,2 Products containing 100% methyl methacrylate monomers in acrylic nails were banned by the US Food and Drug Administration in the early 1970s after receiving a number of complaints.³ However, no regulation prohibits the use of methyl methacrylate monomer in cosmetic products, and various methacrylate and acrylate monomers remain widely used.⁴ With a growing popularity in artificial nails, it is expected the number of sensitized persons will increase.

Acrylate allergy from sculptured nails concern self-curing resins made from a polymer powder and a liquid monomer solution. Advantages of new UV-cured products include the lack of unpleasant smell and simplified modeling. They also do not require an irritant, such as methacrylic acid, as a bonding agent. Instead, 2-HEMA and 2-hydroxypropyl methacrylate are added. These photobonded nails colloquially are called gel nails (acid free) as opposed to acrylic nails (using methacrylic acid as a primer). It is important to note that the esters of acrylic acid but not the acid itself sensitize patients, and sensitization is not caused by the uncured gel or the monomer solution but by the remaining monomers in the cured plastic nail and the dust filings that are produced during the finishing process.

Clinical Presentation

Symptoms of an ACD to nail acrylates include pruritus and fingertip dermatitis along with nail plate dystrophy. There may be pruritus at the nail base, with subsequent dryness, thickening, and onycholysis. The brittle nails may become split, discolored, and develop paronychia. Inadvertent contact with glue monomers or other acrylate-containing substances may cause eczematous lesions at distant sites. Avoidance of the allergen often results in complete restoration of the normal nail and fingertip within months.

Sensitization

Acrylates and methacrylates are ubiquitous materials used for both industrial and commercial applications. Due to their widespread industrial use, contact allergies to acrylates including 2-HEMA, 2-hydroxypropyl methacrylate, and triethyleneglycol diacrylate (TREGDA) are common. Cross-reaction of these compounds has been observed and is postulated to be due to reaction of the (meth)acrylate carboxyethyl group with the receptors of antigen-presenting cells.⁵ As a result, an individual with an acrylate allergy sensitized to one allergen often is allergic to its similar compounds and cross-reactors and must avoid the assortment of compounds containing these ingredients, which is important for individuals with occupational sensitization to a particular acrylate who is subsequently susceptible to other acrylate-containing compounds triggering allergic reactions when reexposure occurs in different settings.

Allergens and Occupational Exposure

Acrylates in cosmetic nail products are a source of ACD for not only the customer but also the manicurist.⁶ The most frequently cited sources of ACD in beauticians are acrylate chemicals.⁷ However, acrylate compounds are an occupational hazard for a number of other specialists, including dentists and dental technicians, histology technicians, and individuals in the printing industry.^8,9 Other individuals may be sensitized to acrylates through their inclusion in adhesives, dental bonding agents, hearing aids, electrocardiogram electrodes, artificial bone cement, and a myriad of other medical and nonmedical applications.^4,10-12 For workers who cannot avoid occupational exposure to these allergens, polyvinyl alcohol and multilayer laminate gloves are recommended, as natural rubber latex gloves do not always provide adequate protection from many of these agents.¹⁰

Testing for Suspected Acrylate Allergy

Cross-reactivity among acrylates is widely considered in the literature but remains enigmatic and is an important consideration with regard to routine patch test screening.¹³ In the case of an acrylate allergy to nail products, using 2-HEMA and ethylene glycol dimethacrylate is effective in detecting sensitization by photobonded nails and in patients sensitized by powder liquid products.¹⁴ One study showed a patch test panel including 2-HEMA, ethylene glycol dimethacrylate, and TREGDA was effective in identifying the majority of individuals with an allergy to acrylates in nail products and nail technicians.¹⁵ Another study has shown the most commonly positive testing allergens to be HEMA, ethyl acrylate, and methyl methacrylate.¹⁶ If one is patch testing only one chemical, it appears 2-HEMA is preferred.¹⁷ However, broader panels of screening allergens are necessary to achieve an accurate diagnosis. Furthermore, different panels of test allergens have been shown to vary in their ability to detect an acrylate allergy in different occupational exposures.¹² 

The time to patch test read also is important. A standard read at 72 hours is warranted; however, one study showed if only one read at day 3 was done without a subsequent day 7 read, then 25% of TREGDA and 50% of 2-HEMA allergies would have been missed in patients with occupational acrylate allergy.¹⁵ Other studies have reported late-appearing and long-lasting test reactions when testing for an acrylate allergy.^18,19 Clinicians should be cognizant that an acrylate allergy may be present even if initial screening is negative but the history and clinical picture are suggestive.

The Diagnosis: Allergic Contact Dermatitis

An allergic contact dermatitis (ACD) to acrylates was suspected and 4 patches were applied to the forearm (the North American Standard Series of the North American Contact Dermatitis Group). The patches were 2-hydroxyethyl methacrylate (2-HEMA) 2.0% permissible exposure limit (peL), ethyl acrylate 0.1% peL, tosylamide formaldehyde resin 10.0% peL, and methyl methacrylate 2.0% peL. A reading at 72 hours was performed and showed a positive reaction to hydroxyethyl methacrylate, ethyl acrylate, and methyl methacrylate, and a negative patch test to tosylamide formaldehyde resin (nail polish)(Figure). The patient was diagnosed with an allergic contact hypersensitivity to the aforementioned acrylates and instructed to avoid artificial nails and acrylate glues. She also was started on oral biotin supplements. On 6-month follow-up the patient had regrowth of all 10 fingernails without brittleness or splitting. She was able to use nail polishes but avoided all acrylic artificial nails and acrylate-containing personal care products.

Acrylate Allergy and Artificial Nails

Acrylates are plastic materials formed by polymerization of acrylic or methacrylic acid monomers and have been cited as a major cause of occupational and nonoccupational contact dermatitis. Contact dermatitis to acrylates in artificial nails was first reported in the 1950s.^1,2 Products containing 100% methyl methacrylate monomers in acrylic nails were banned by the US Food and Drug Administration in the early 1970s after receiving a number of complaints.³ However, no regulation prohibits the use of methyl methacrylate monomer in cosmetic products, and various methacrylate and acrylate monomers remain widely used.⁴ With a growing popularity in artificial nails, it is expected the number of sensitized persons will increase.

Acrylate allergy from sculptured nails concern self-curing resins made from a polymer powder and a liquid monomer solution. Advantages of new UV-cured products include the lack of unpleasant smell and simplified modeling. They also do not require an irritant, such as methacrylic acid, as a bonding agent. Instead, 2-HEMA and 2-hydroxypropyl methacrylate are added. These photobonded nails colloquially are called gel nails (acid free) as opposed to acrylic nails (using methacrylic acid as a primer). It is important to note that the esters of acrylic acid but not the acid itself sensitize patients, and sensitization is not caused by the uncured gel or the monomer solution but by the remaining monomers in the cured plastic nail and the dust filings that are produced during the finishing process.

Clinical Presentation

Symptoms of an ACD to nail acrylates include pruritus and fingertip dermatitis along with nail plate dystrophy. There may be pruritus at the nail base, with subsequent dryness, thickening, and onycholysis. The brittle nails may become split, discolored, and develop paronychia. Inadvertent contact with glue monomers or other acrylate-containing substances may cause eczematous lesions at distant sites. Avoidance of the allergen often results in complete restoration of the normal nail and fingertip within months.

Sensitization

Acrylates and methacrylates are ubiquitous materials used for both industrial and commercial applications. Due to their widespread industrial use, contact allergies to acrylates including 2-HEMA, 2-hydroxypropyl methacrylate, and triethyleneglycol diacrylate (TREGDA) are common. Cross-reaction of these compounds has been observed and is postulated to be due to reaction of the (meth)acrylate carboxyethyl group with the receptors of antigen-presenting cells.⁵ As a result, an individual with an acrylate allergy sensitized to one allergen often is allergic to its similar compounds and cross-reactors and must avoid the assortment of compounds containing these ingredients, which is important for individuals with occupational sensitization to a particular acrylate who is subsequently susceptible to other acrylate-containing compounds triggering allergic reactions when reexposure occurs in different settings.

Allergens and Occupational Exposure

Acrylates in cosmetic nail products are a source of ACD for not only the customer but also the manicurist.⁶ The most frequently cited sources of ACD in beauticians are acrylate chemicals.⁷ However, acrylate compounds are an occupational hazard for a number of other specialists, including dentists and dental technicians, histology technicians, and individuals in the printing industry.^8,9 Other individuals may be sensitized to acrylates through their inclusion in adhesives, dental bonding agents, hearing aids, electrocardiogram electrodes, artificial bone cement, and a myriad of other medical and nonmedical applications.^4,10-12 For workers who cannot avoid occupational exposure to these allergens, polyvinyl alcohol and multilayer laminate gloves are recommended, as natural rubber latex gloves do not always provide adequate protection from many of these agents.¹⁰

Testing for Suspected Acrylate Allergy

Cross-reactivity among acrylates is widely considered in the literature but remains enigmatic and is an important consideration with regard to routine patch test screening.¹³ In the case of an acrylate allergy to nail products, using 2-HEMA and ethylene glycol dimethacrylate is effective in detecting sensitization by photobonded nails and in patients sensitized by powder liquid products.¹⁴ One study showed a patch test panel including 2-HEMA, ethylene glycol dimethacrylate, and TREGDA was effective in identifying the majority of individuals with an allergy to acrylates in nail products and nail technicians.¹⁵ Another study has shown the most commonly positive testing allergens to be HEMA, ethyl acrylate, and methyl methacrylate.¹⁶ If one is patch testing only one chemical, it appears 2-HEMA is preferred.¹⁷ However, broader panels of screening allergens are necessary to achieve an accurate diagnosis. Furthermore, different panels of test allergens have been shown to vary in their ability to detect an acrylate allergy in different occupational exposures.¹² 

The time to patch test read also is important. A standard read at 72 hours is warranted; however, one study showed if only one read at day 3 was done without a subsequent day 7 read, then 25% of TREGDA and 50% of 2-HEMA allergies would have been missed in patients with occupational acrylate allergy.¹⁵ Other studies have reported late-appearing and long-lasting test reactions when testing for an acrylate allergy.^18,19 Clinicians should be cognizant that an acrylate allergy may be present even if initial screening is negative but the history and clinical picture are suggestive.

The Diagnosis: Pemphigus Vegetans

Pemphigus vegetans is a rare variant of pemphigus vulgaris. Clinically, pemphigus vegetans is characterized by vegetative lesions over the flexures, but any area of the skin may be involved. There have been case reports involving the scalp,^1,2 mouth,³ and foot.⁴ There are 2 clinical subtypes: the Neumann type and the Hallopeau type.⁵ The Hallopeau type is relatively benign, requires lower doses of systemic corticosteroids, and has a prolonged remission, while the Neumann type necessitates higher doses of systemic corticosteroids and often presents with relapses and remissions.

The diagnosis of pemphigus vegetans is based on clinical suspicion and confirmed by histological examination and immunological findings. The diagnosis may be difficult, as its presentation varies and histopathological findings may resemble other conditions.

Systemic corticosteroids are the well-established drug of choice for treating pemphigus vegetans to induce remission and maintain healing before cautiously tapering down the dosage approximately 50% every 2 weeks.⁶ Adjuvant drugs used in conjunction with steroids for steroid-sparing purpose include azathioprine, cyclophosphamide, mycophenolate mofetil, methotrexate, and cyclosporine.⁶ Pulsed intravenous steroids,⁷ intravenous immunoglobulins,⁸ pulsed dexamethasone cyclophosphamide,⁹ and extracorporeal photopheresis¹⁰ are given for severe and recalcitrant disease.

Laboratory investigations of our patient showed a normal complete blood cell count and a normal renal and liver profile. Herpes simplex virus serology was positive for type 1 and type 2 IgM and IgG. Urethral swab was dry and negative for gonorrhea. Serology for chlamydia, toxoplasma, amoebiasis, and leishmaniasis was negative. Human immunodeficiency virus serology, hepatitis screening, rapid plasma reagin, Treponema pallidum hemagglutination, rheumatoid factor, and antinuclear antibody all were negative. The patient was given a course of oral acyclovir 400 mg 3 times daily and empirical treatment with oral doxycycline 100 mg twice daily for a week with no clinical response.

Two biopsies from the perianal ulcers showed inflamed squamous papillomata with no Donovan bodies. A third biopsy from an intact blister showed acantholytic cells in the suprabasal bullae with eosinophilic and lymphocytic infiltrates at the upper dermis. Direct immunofluorescence demonstrated intercellular C3 and IgG deposits.

The patient was started on oral prednisolone at 1 mg/kg daily and oral azathioprine 50 mg daily with resolution of the perianal, penile, and oral ulcers (Figures 1 and 2). He achieved good suppression of further eruption. At the patient's most recent follow-up (2.5 years after the initial presentation), he was in remission and was currently taking oral azathioprine 100 mg once daily and no oral corticosteroids.

The Diagnosis: Pemphigus Vegetans

Pemphigus vegetans is a rare variant of pemphigus vulgaris. Clinically, pemphigus vegetans is characterized by vegetative lesions over the flexures, but any area of the skin may be involved. There have been case reports involving the scalp,^1,2 mouth,³ and foot.⁴ There are 2 clinical subtypes: the Neumann type and the Hallopeau type.⁵ The Hallopeau type is relatively benign, requires lower doses of systemic corticosteroids, and has a prolonged remission, while the Neumann type necessitates higher doses of systemic corticosteroids and often presents with relapses and remissions.

The diagnosis of pemphigus vegetans is based on clinical suspicion and confirmed by histological examination and immunological findings. The diagnosis may be difficult, as its presentation varies and histopathological findings may resemble other conditions.

Systemic corticosteroids are the well-established drug of choice for treating pemphigus vegetans to induce remission and maintain healing before cautiously tapering down the dosage approximately 50% every 2 weeks.⁶ Adjuvant drugs used in conjunction with steroids for steroid-sparing purpose include azathioprine, cyclophosphamide, mycophenolate mofetil, methotrexate, and cyclosporine.⁶ Pulsed intravenous steroids,⁷ intravenous immunoglobulins,⁸ pulsed dexamethasone cyclophosphamide,⁹ and extracorporeal photopheresis¹⁰ are given for severe and recalcitrant disease.

Laboratory investigations of our patient showed a normal complete blood cell count and a normal renal and liver profile. Herpes simplex virus serology was positive for type 1 and type 2 IgM and IgG. Urethral swab was dry and negative for gonorrhea. Serology for chlamydia, toxoplasma, amoebiasis, and leishmaniasis was negative. Human immunodeficiency virus serology, hepatitis screening, rapid plasma reagin, Treponema pallidum hemagglutination, rheumatoid factor, and antinuclear antibody all were negative. The patient was given a course of oral acyclovir 400 mg 3 times daily and empirical treatment with oral doxycycline 100 mg twice daily for a week with no clinical response.

Two biopsies from the perianal ulcers showed inflamed squamous papillomata with no Donovan bodies. A third biopsy from an intact blister showed acantholytic cells in the suprabasal bullae with eosinophilic and lymphocytic infiltrates at the upper dermis. Direct immunofluorescence demonstrated intercellular C3 and IgG deposits.

The patient was started on oral prednisolone at 1 mg/kg daily and oral azathioprine 50 mg daily with resolution of the perianal, penile, and oral ulcers (Figures 1 and 2). He achieved good suppression of further eruption. At the patient's most recent follow-up (2.5 years after the initial presentation), he was in remission and was currently taking oral azathioprine 100 mg once daily and no oral corticosteroids.

The Diagnosis: Pemphigus Vegetans

Pemphigus vegetans is a rare variant of pemphigus vulgaris. Clinically, pemphigus vegetans is characterized by vegetative lesions over the flexures, but any area of the skin may be involved. There have been case reports involving the scalp,^1,2 mouth,³ and foot.⁴ There are 2 clinical subtypes: the Neumann type and the Hallopeau type.⁵ The Hallopeau type is relatively benign, requires lower doses of systemic corticosteroids, and has a prolonged remission, while the Neumann type necessitates higher doses of systemic corticosteroids and often presents with relapses and remissions.

The diagnosis of pemphigus vegetans is based on clinical suspicion and confirmed by histological examination and immunological findings. The diagnosis may be difficult, as its presentation varies and histopathological findings may resemble other conditions.

Systemic corticosteroids are the well-established drug of choice for treating pemphigus vegetans to induce remission and maintain healing before cautiously tapering down the dosage approximately 50% every 2 weeks.⁶ Adjuvant drugs used in conjunction with steroids for steroid-sparing purpose include azathioprine, cyclophosphamide, mycophenolate mofetil, methotrexate, and cyclosporine.⁶ Pulsed intravenous steroids,⁷ intravenous immunoglobulins,⁸ pulsed dexamethasone cyclophosphamide,⁹ and extracorporeal photopheresis¹⁰ are given for severe and recalcitrant disease.

Laboratory investigations of our patient showed a normal complete blood cell count and a normal renal and liver profile. Herpes simplex virus serology was positive for type 1 and type 2 IgM and IgG. Urethral swab was dry and negative for gonorrhea. Serology for chlamydia, toxoplasma, amoebiasis, and leishmaniasis was negative. Human immunodeficiency virus serology, hepatitis screening, rapid plasma reagin, Treponema pallidum hemagglutination, rheumatoid factor, and antinuclear antibody all were negative. The patient was given a course of oral acyclovir 400 mg 3 times daily and empirical treatment with oral doxycycline 100 mg twice daily for a week with no clinical response.

Two biopsies from the perianal ulcers showed inflamed squamous papillomata with no Donovan bodies. A third biopsy from an intact blister showed acantholytic cells in the suprabasal bullae with eosinophilic and lymphocytic infiltrates at the upper dermis. Direct immunofluorescence demonstrated intercellular C3 and IgG deposits.

The patient was started on oral prednisolone at 1 mg/kg daily and oral azathioprine 50 mg daily with resolution of the perianal, penile, and oral ulcers (Figures 1 and 2). He achieved good suppression of further eruption. At the patient's most recent follow-up (2.5 years after the initial presentation), he was in remission and was currently taking oral azathioprine 100 mg once daily and no oral corticosteroids.

Foscarnet-Induced Ulceration

Viral swabs were negative for herpes simplex virus. The diagnosis of foscarnet-induced ulceration was reached and the drug was discontinued. Symptomatic treatment with soap substitutes and lidocaine ointment was used.

Foscarnet is an antiviral agent used when resistance develops to first-line therapies.¹ It is a pyrophosphate analogue that inhibits viral DNA polymerase, thereby preventing viral replication. It is used in treating cytomegalovirus and herpes simplex virus, which are resistant to first-line therapies, or patients who develop hematologic toxicity from antivirals. The main side effects of foscarnet include nephrotoxicity, alteration of calcium homeostasis, and malaise. Genital ulceration is a known side effect of therapy, though it is rare and more commonly seen in uncircumcised males. Approximately 94% of the drug is excreted unchanged in the urine, which causes an irritant dermatitis that is more pronounced in males as the urine stays in the subpreputial area.¹

Vulval ulceration² and penile ulceration³ has been reported in AIDS patients treated with foscarnet. In these patients, the onset of ulceration is temporally related to foscarnet therapy, occurring at approximately day 7 to 24 of treatment and resolving after discontinuation of therapy.

Foscarnet-Induced Ulceration

Viral swabs were negative for herpes simplex virus. The diagnosis of foscarnet-induced ulceration was reached and the drug was discontinued. Symptomatic treatment with soap substitutes and lidocaine ointment was used.

Foscarnet is an antiviral agent used when resistance develops to first-line therapies.¹ It is a pyrophosphate analogue that inhibits viral DNA polymerase, thereby preventing viral replication. It is used in treating cytomegalovirus and herpes simplex virus, which are resistant to first-line therapies, or patients who develop hematologic toxicity from antivirals. The main side effects of foscarnet include nephrotoxicity, alteration of calcium homeostasis, and malaise. Genital ulceration is a known side effect of therapy, though it is rare and more commonly seen in uncircumcised males. Approximately 94% of the drug is excreted unchanged in the urine, which causes an irritant dermatitis that is more pronounced in males as the urine stays in the subpreputial area.¹

Vulval ulceration² and penile ulceration³ has been reported in AIDS patients treated with foscarnet. In these patients, the onset of ulceration is temporally related to foscarnet therapy, occurring at approximately day 7 to 24 of treatment and resolving after discontinuation of therapy.

Foscarnet-Induced Ulceration

Viral swabs were negative for herpes simplex virus. The diagnosis of foscarnet-induced ulceration was reached and the drug was discontinued. Symptomatic treatment with soap substitutes and lidocaine ointment was used.

Foscarnet is an antiviral agent used when resistance develops to first-line therapies.¹ It is a pyrophosphate analogue that inhibits viral DNA polymerase, thereby preventing viral replication. It is used in treating cytomegalovirus and herpes simplex virus, which are resistant to first-line therapies, or patients who develop hematologic toxicity from antivirals. The main side effects of foscarnet include nephrotoxicity, alteration of calcium homeostasis, and malaise. Genital ulceration is a known side effect of therapy, though it is rare and more commonly seen in uncircumcised males. Approximately 94% of the drug is excreted unchanged in the urine, which causes an irritant dermatitis that is more pronounced in males as the urine stays in the subpreputial area.¹

Vulval ulceration² and penile ulceration³ has been reported in AIDS patients treated with foscarnet. In these patients, the onset of ulceration is temporally related to foscarnet therapy, occurring at approximately day 7 to 24 of treatment and resolving after discontinuation of therapy.

The Diagnosis: Blaschkoid Graft-vs-host Disease

The patient had a history of myelodysplastic syndrome and underwent a bone marrow transplant 1 year prior to presentation. She had acute graft-vs-host disease (GVHD) 6 weeks following the transplant, which resolved with high-dose prednisone followed by UVB phototherapy. Skin biopsy demonstrated lichenoid dermatitis with vacuolar degeneration, dyskeratosis, and prominent pigment incontinence (Figure). Based on these findings and her clinical presentation, a diagnosis of blaschkoid GVHD was made.

Although acute GVHD is the result of immunocompetent donor T cells recognizing host tissues as foreign and initiating an immune response, the pathophysiology of chronic GVHD is not well understood.^1,2 Theories for disease pathogenesis in chronic GVHD suggest an underlying autoimmune and/or alloreactive process.^2-5 The skin often is the first organ affected in acute GVHD, and patients generally present with a pruritic morbilliform eruption that begins on the trunk and spreads to the rest of the body.^1,2 Cutaneous manifestations of chronic GVHD may be protean. Lesions can resemble systemic sclerosis or morphea, lichen planus, psoriasis, ichthyosis, and many other conditions.²

The differential diagnosis of linear dermatoses includes herpes zoster, contact dermatitis, lichen striatus (blaschkitis), nevus unius lateris, inflammatory linear verrucous epidermal nevus, and incontinentia pigmenti.^6,7 Lichen planus-like chronic GVHD occurring in a linear distribution has been described.^6-14 Distinction between dermatomal and blaschkoid processes is diagnostically important. In the case of GVHD, dermatomal distribution may suggest an association between GVHD and prior herpes simplex virus or varicella-zoster virus infection.^6,8 Herpesvirus may alter surface antigens of keratinocytes, rendering them targets of donor lymphocytes, and antibodies to viral particles may cross-react with host keratinocyte HLA antigens. It also is possible that dermatomal GVHD may simply be a type of isomorphic response (Köbner phenomenon).⁸

When cutaneous GVHD follows Blaschko lines, other mechanisms appear to be at play.^9-14 It is plausible that these patients have an underlying genetic mosaicism, perhaps the result of a postzygotic mutation, that results in a daughter cell population that expresses surface antigens different from those of the primary cell population found elsewhere in the skin. Donor lymphocytes may selectively react to this mosaic population, leading to the clinical picture of chronic GVHD oriented along Blaschko lines.^10,11,13,14 

In conclusion, lichenoid linear GVHD following Blaschko lines is an uncommon presentation of chronic GVHD that highlights the heterogeneity of this disease and should be considered in the appropriate clinical setting.

The Diagnosis: Blaschkoid Graft-vs-host Disease

The patient had a history of myelodysplastic syndrome and underwent a bone marrow transplant 1 year prior to presentation. She had acute graft-vs-host disease (GVHD) 6 weeks following the transplant, which resolved with high-dose prednisone followed by UVB phototherapy. Skin biopsy demonstrated lichenoid dermatitis with vacuolar degeneration, dyskeratosis, and prominent pigment incontinence (Figure). Based on these findings and her clinical presentation, a diagnosis of blaschkoid GVHD was made.

Although acute GVHD is the result of immunocompetent donor T cells recognizing host tissues as foreign and initiating an immune response, the pathophysiology of chronic GVHD is not well understood.^1,2 Theories for disease pathogenesis in chronic GVHD suggest an underlying autoimmune and/or alloreactive process.^2-5 The skin often is the first organ affected in acute GVHD, and patients generally present with a pruritic morbilliform eruption that begins on the trunk and spreads to the rest of the body.^1,2 Cutaneous manifestations of chronic GVHD may be protean. Lesions can resemble systemic sclerosis or morphea, lichen planus, psoriasis, ichthyosis, and many other conditions.²

The differential diagnosis of linear dermatoses includes herpes zoster, contact dermatitis, lichen striatus (blaschkitis), nevus unius lateris, inflammatory linear verrucous epidermal nevus, and incontinentia pigmenti.^6,7 Lichen planus-like chronic GVHD occurring in a linear distribution has been described.^6-14 Distinction between dermatomal and blaschkoid processes is diagnostically important. In the case of GVHD, dermatomal distribution may suggest an association between GVHD and prior herpes simplex virus or varicella-zoster virus infection.^6,8 Herpesvirus may alter surface antigens of keratinocytes, rendering them targets of donor lymphocytes, and antibodies to viral particles may cross-react with host keratinocyte HLA antigens. It also is possible that dermatomal GVHD may simply be a type of isomorphic response (Köbner phenomenon).⁸

When cutaneous GVHD follows Blaschko lines, other mechanisms appear to be at play.^9-14 It is plausible that these patients have an underlying genetic mosaicism, perhaps the result of a postzygotic mutation, that results in a daughter cell population that expresses surface antigens different from those of the primary cell population found elsewhere in the skin. Donor lymphocytes may selectively react to this mosaic population, leading to the clinical picture of chronic GVHD oriented along Blaschko lines.^10,11,13,14 

In conclusion, lichenoid linear GVHD following Blaschko lines is an uncommon presentation of chronic GVHD that highlights the heterogeneity of this disease and should be considered in the appropriate clinical setting.

The Diagnosis: Blaschkoid Graft-vs-host Disease

The patient had a history of myelodysplastic syndrome and underwent a bone marrow transplant 1 year prior to presentation. She had acute graft-vs-host disease (GVHD) 6 weeks following the transplant, which resolved with high-dose prednisone followed by UVB phototherapy. Skin biopsy demonstrated lichenoid dermatitis with vacuolar degeneration, dyskeratosis, and prominent pigment incontinence (Figure). Based on these findings and her clinical presentation, a diagnosis of blaschkoid GVHD was made.

Although acute GVHD is the result of immunocompetent donor T cells recognizing host tissues as foreign and initiating an immune response, the pathophysiology of chronic GVHD is not well understood.^1,2 Theories for disease pathogenesis in chronic GVHD suggest an underlying autoimmune and/or alloreactive process.^2-5 The skin often is the first organ affected in acute GVHD, and patients generally present with a pruritic morbilliform eruption that begins on the trunk and spreads to the rest of the body.^1,2 Cutaneous manifestations of chronic GVHD may be protean. Lesions can resemble systemic sclerosis or morphea, lichen planus, psoriasis, ichthyosis, and many other conditions.²

The differential diagnosis of linear dermatoses includes herpes zoster, contact dermatitis, lichen striatus (blaschkitis), nevus unius lateris, inflammatory linear verrucous epidermal nevus, and incontinentia pigmenti.^6,7 Lichen planus-like chronic GVHD occurring in a linear distribution has been described.^6-14 Distinction between dermatomal and blaschkoid processes is diagnostically important. In the case of GVHD, dermatomal distribution may suggest an association between GVHD and prior herpes simplex virus or varicella-zoster virus infection.^6,8 Herpesvirus may alter surface antigens of keratinocytes, rendering them targets of donor lymphocytes, and antibodies to viral particles may cross-react with host keratinocyte HLA antigens. It also is possible that dermatomal GVHD may simply be a type of isomorphic response (Köbner phenomenon).⁸

When cutaneous GVHD follows Blaschko lines, other mechanisms appear to be at play.^9-14 It is plausible that these patients have an underlying genetic mosaicism, perhaps the result of a postzygotic mutation, that results in a daughter cell population that expresses surface antigens different from those of the primary cell population found elsewhere in the skin. Donor lymphocytes may selectively react to this mosaic population, leading to the clinical picture of chronic GVHD oriented along Blaschko lines.^10,11,13,14 

In conclusion, lichenoid linear GVHD following Blaschko lines is an uncommon presentation of chronic GVHD that highlights the heterogeneity of this disease and should be considered in the appropriate clinical setting.

The Diagnosis: Chronic Hyperplastic Candidiasis (Nodular Form)

Chronic hyperplastic candidiasis (CHC) is a rare form of oropharyngeal candidiasis. The most frequent clinical presentation is a white plaque that cannot be detached (also known as candidal leukoplakia). It usually involves the anterior buccal mucosa, mainly the commissural area, though the palate and tongue also can be affected. The nodular type of CHC is even less common. Our patient exhibited the typical clinical presentation of the nodular type of CHC.^1-3 The differential diagnosis includes leukoplakia, premalignant and malignant epithelial lesions, granular cell tumor, and florid oral papillomatosis.^1,3 A biopsy usually is required for diagnostic confirmation. Histologically, CHC is characterized by parakeratosis and a hyperplastic epithelium invaded by Candida hyphae.⁴ Because Candida species are commensal in up to 50% of the healthy population, superficial colonization of tissues is not enough to indicate notable disease.¹ In our patient, the histopathology revealed a hyperplastic mucosa without atypia and numerous hyphae (Figure). Both lingual swab and tissue cultures revealed high growth of Candida albicans. 

Infection by C albicans depends on pathogen virulence and host factors such as wearing dentures, reduced salivary production, smoking habit, or immunosuppression.^1,4 Apart from wearing dentures, our patient did not present with other predisposing factors. It is possible that the immunosuppressive status related to old age and associated oral changes contributed to Candida infection in this case. 

Topical or systemic antifungal agents together with the elimination of predisposing factors are usual first-line treatments. Because of the relationship with atypia and the possibility of evolving into carcinoma in untreated or persistent lesions, follow-up is necessary to verify complete resolution after treatment.^1,3,4 In the case reported herein, the lesions disappeared after 15 days of oral fluconazole treatment.

The Diagnosis: Chronic Hyperplastic Candidiasis (Nodular Form)

Chronic hyperplastic candidiasis (CHC) is a rare form of oropharyngeal candidiasis. The most frequent clinical presentation is a white plaque that cannot be detached (also known as candidal leukoplakia). It usually involves the anterior buccal mucosa, mainly the commissural area, though the palate and tongue also can be affected. The nodular type of CHC is even less common. Our patient exhibited the typical clinical presentation of the nodular type of CHC.^1-3 The differential diagnosis includes leukoplakia, premalignant and malignant epithelial lesions, granular cell tumor, and florid oral papillomatosis.^1,3 A biopsy usually is required for diagnostic confirmation. Histologically, CHC is characterized by parakeratosis and a hyperplastic epithelium invaded by Candida hyphae.⁴ Because Candida species are commensal in up to 50% of the healthy population, superficial colonization of tissues is not enough to indicate notable disease.¹ In our patient, the histopathology revealed a hyperplastic mucosa without atypia and numerous hyphae (Figure). Both lingual swab and tissue cultures revealed high growth of Candida albicans. 

Infection by C albicans depends on pathogen virulence and host factors such as wearing dentures, reduced salivary production, smoking habit, or immunosuppression.^1,4 Apart from wearing dentures, our patient did not present with other predisposing factors. It is possible that the immunosuppressive status related to old age and associated oral changes contributed to Candida infection in this case. 

Topical or systemic antifungal agents together with the elimination of predisposing factors are usual first-line treatments. Because of the relationship with atypia and the possibility of evolving into carcinoma in untreated or persistent lesions, follow-up is necessary to verify complete resolution after treatment.^1,3,4 In the case reported herein, the lesions disappeared after 15 days of oral fluconazole treatment.

The Diagnosis: Chronic Hyperplastic Candidiasis (Nodular Form)

Chronic hyperplastic candidiasis (CHC) is a rare form of oropharyngeal candidiasis. The most frequent clinical presentation is a white plaque that cannot be detached (also known as candidal leukoplakia). It usually involves the anterior buccal mucosa, mainly the commissural area, though the palate and tongue also can be affected. The nodular type of CHC is even less common. Our patient exhibited the typical clinical presentation of the nodular type of CHC.^1-3 The differential diagnosis includes leukoplakia, premalignant and malignant epithelial lesions, granular cell tumor, and florid oral papillomatosis.^1,3 A biopsy usually is required for diagnostic confirmation. Histologically, CHC is characterized by parakeratosis and a hyperplastic epithelium invaded by Candida hyphae.⁴ Because Candida species are commensal in up to 50% of the healthy population, superficial colonization of tissues is not enough to indicate notable disease.¹ In our patient, the histopathology revealed a hyperplastic mucosa without atypia and numerous hyphae (Figure). Both lingual swab and tissue cultures revealed high growth of Candida albicans. 

Infection by C albicans depends on pathogen virulence and host factors such as wearing dentures, reduced salivary production, smoking habit, or immunosuppression.^1,4 Apart from wearing dentures, our patient did not present with other predisposing factors. It is possible that the immunosuppressive status related to old age and associated oral changes contributed to Candida infection in this case. 

Topical or systemic antifungal agents together with the elimination of predisposing factors are usual first-line treatments. Because of the relationship with atypia and the possibility of evolving into carcinoma in untreated or persistent lesions, follow-up is necessary to verify complete resolution after treatment.^1,3,4 In the case reported herein, the lesions disappeared after 15 days of oral fluconazole treatment.

The Diagnosis: Metastatic Renal Cell Carcinoma

A shave biopsy of the right occipital scalp lesion demonstrated large clear cells arranged in oval nests with mildly atypical central nuclei (Figure). The findings were consistent with the clear cell type of metastatic renal cell carcinoma (mRCC) with tumor involvement in the deep margin. PAX8 immunostain was positive in the tumor, further supporting the diagnosis of mRCC.

The most common patient demographic diagnosed with renal cell carcinoma (RCC) is men in the sixth and seventh decades of life.^1,2 The classic presentation of RCC includes the triad of flank pain, hematuria, and a palpable abdominal mass. Other symptoms may include fatigue, weight loss, and anemia; however, small localized tumors rarely are symptomatic, and less than 10% of patients with RCC present with this classic triad.³ Many RCCs are diagnosed from incidental findings on abdominal imaging or from the presentation of metastatic disease.^1,2 The lungs, bones, and liver are the most common sites of metastases, while skin metastases are rare.² One study found only 3.3% (10/306) of RCC cases had cutaneous metastases and the scalp was the most common location. In half of these patients, the skin metastases were present at initial RCC diagnosis.⁴

The most common presentation of a cutaneous metastasis of RCC entails the rapid development of a reddish blue nodule on the face or scalp.^4,5 The differential diagnosis may include basal cell carcinoma, hemangioma, cutaneous angiosarcoma, pyogenic granuloma, and atypical fibroxanthoma. Careful elicitation of a medical history indicating any of the classic or systemic signs associated with RCC or a personal history of RCC should raise the suspicion for mRCC and prompt a biopsy.

Clear cell RCC is the most common type of primary RCC and 81% of mRCCs were found to be of the clear cell type. Clear cell RCC classically exhibits clear ballooned cytoplasm with distinct cell borders.⁶ Immunohistochemistry stains with PAX2 and PAX8 are helpful in diagnosing the renal origin of the metastatic tissue, with PAX8 being especially helpful (89% sensitivity).⁷

The von Hippel-Lindau gene, VHL, is involved in up to 60% of sporadic clear cell RCC cases, in addition to its involvement in VHL syndrome.1 von Hippel-Lindau syndrome is associated with clear cell RCC, retinal angiomas, hemangioblastomas of the central nervous system, and pheochromocytomas.¹ The mutated VHL gene is associated with an increased expression of vascular endothelial growth factor (VEGF), which promotes angiogenesis, endothelial mutagenesis, and vascular permeability.⁸ These physiologic responses are likely responsible for the proliferation and dissemination of neoplastic cells in clear cell RCC.⁹ The understanding of this pathogenic mechanism has led to the development of targeted effective treatments in RCC.

Systemic treatments for mRCC are rapidly evolving and improving.⁹ Vascular endothelial growth factor tyrosine kinase inhibitors such as sorafenib, sunitinib, and pazopanib, as well as the VEGF monoclonal antibody bevacizumab, have all demonstrated notable efficacy in the treatment of RCC. Phase 3 clinical trials for the treatment of mRCC have demonstrated that the new, more biochemically potent VEGF tyrosine kinase inhibitor axitinib has superior efficacy to sorafenib, the prior standard of care.⁹ Our patient noted that the cutaneous mRCC lesion seemed to be improving after starting treatment with axitinib 2 months prior to presentation. In addition to systemic chemotherapy, the surgical removal of lesions often is indicated for the treatment of cutaneous mRCC.^5,10 Our patient has continued axitinib and is doing well.

The Diagnosis: Metastatic Renal Cell Carcinoma

A shave biopsy of the right occipital scalp lesion demonstrated large clear cells arranged in oval nests with mildly atypical central nuclei (Figure). The findings were consistent with the clear cell type of metastatic renal cell carcinoma (mRCC) with tumor involvement in the deep margin. PAX8 immunostain was positive in the tumor, further supporting the diagnosis of mRCC.

The most common patient demographic diagnosed with renal cell carcinoma (RCC) is men in the sixth and seventh decades of life.^1,2 The classic presentation of RCC includes the triad of flank pain, hematuria, and a palpable abdominal mass. Other symptoms may include fatigue, weight loss, and anemia; however, small localized tumors rarely are symptomatic, and less than 10% of patients with RCC present with this classic triad.³ Many RCCs are diagnosed from incidental findings on abdominal imaging or from the presentation of metastatic disease.^1,2 The lungs, bones, and liver are the most common sites of metastases, while skin metastases are rare.² One study found only 3.3% (10/306) of RCC cases had cutaneous metastases and the scalp was the most common location. In half of these patients, the skin metastases were present at initial RCC diagnosis.⁴

The most common presentation of a cutaneous metastasis of RCC entails the rapid development of a reddish blue nodule on the face or scalp.^4,5 The differential diagnosis may include basal cell carcinoma, hemangioma, cutaneous angiosarcoma, pyogenic granuloma, and atypical fibroxanthoma. Careful elicitation of a medical history indicating any of the classic or systemic signs associated with RCC or a personal history of RCC should raise the suspicion for mRCC and prompt a biopsy.

Clear cell RCC is the most common type of primary RCC and 81% of mRCCs were found to be of the clear cell type. Clear cell RCC classically exhibits clear ballooned cytoplasm with distinct cell borders.⁶ Immunohistochemistry stains with PAX2 and PAX8 are helpful in diagnosing the renal origin of the metastatic tissue, with PAX8 being especially helpful (89% sensitivity).⁷

The von Hippel-Lindau gene, VHL, is involved in up to 60% of sporadic clear cell RCC cases, in addition to its involvement in VHL syndrome.1 von Hippel-Lindau syndrome is associated with clear cell RCC, retinal angiomas, hemangioblastomas of the central nervous system, and pheochromocytomas.¹ The mutated VHL gene is associated with an increased expression of vascular endothelial growth factor (VEGF), which promotes angiogenesis, endothelial mutagenesis, and vascular permeability.⁸ These physiologic responses are likely responsible for the proliferation and dissemination of neoplastic cells in clear cell RCC.⁹ The understanding of this pathogenic mechanism has led to the development of targeted effective treatments in RCC.

Systemic treatments for mRCC are rapidly evolving and improving.⁹ Vascular endothelial growth factor tyrosine kinase inhibitors such as sorafenib, sunitinib, and pazopanib, as well as the VEGF monoclonal antibody bevacizumab, have all demonstrated notable efficacy in the treatment of RCC. Phase 3 clinical trials for the treatment of mRCC have demonstrated that the new, more biochemically potent VEGF tyrosine kinase inhibitor axitinib has superior efficacy to sorafenib, the prior standard of care.⁹ Our patient noted that the cutaneous mRCC lesion seemed to be improving after starting treatment with axitinib 2 months prior to presentation. In addition to systemic chemotherapy, the surgical removal of lesions often is indicated for the treatment of cutaneous mRCC.^5,10 Our patient has continued axitinib and is doing well.

The Diagnosis: Metastatic Renal Cell Carcinoma

A shave biopsy of the right occipital scalp lesion demonstrated large clear cells arranged in oval nests with mildly atypical central nuclei (Figure). The findings were consistent with the clear cell type of metastatic renal cell carcinoma (mRCC) with tumor involvement in the deep margin. PAX8 immunostain was positive in the tumor, further supporting the diagnosis of mRCC.

The most common patient demographic diagnosed with renal cell carcinoma (RCC) is men in the sixth and seventh decades of life.^1,2 The classic presentation of RCC includes the triad of flank pain, hematuria, and a palpable abdominal mass. Other symptoms may include fatigue, weight loss, and anemia; however, small localized tumors rarely are symptomatic, and less than 10% of patients with RCC present with this classic triad.³ Many RCCs are diagnosed from incidental findings on abdominal imaging or from the presentation of metastatic disease.^1,2 The lungs, bones, and liver are the most common sites of metastases, while skin metastases are rare.² One study found only 3.3% (10/306) of RCC cases had cutaneous metastases and the scalp was the most common location. In half of these patients, the skin metastases were present at initial RCC diagnosis.⁴

The most common presentation of a cutaneous metastasis of RCC entails the rapid development of a reddish blue nodule on the face or scalp.^4,5 The differential diagnosis may include basal cell carcinoma, hemangioma, cutaneous angiosarcoma, pyogenic granuloma, and atypical fibroxanthoma. Careful elicitation of a medical history indicating any of the classic or systemic signs associated with RCC or a personal history of RCC should raise the suspicion for mRCC and prompt a biopsy.

Clear cell RCC is the most common type of primary RCC and 81% of mRCCs were found to be of the clear cell type. Clear cell RCC classically exhibits clear ballooned cytoplasm with distinct cell borders.⁶ Immunohistochemistry stains with PAX2 and PAX8 are helpful in diagnosing the renal origin of the metastatic tissue, with PAX8 being especially helpful (89% sensitivity).⁷

The von Hippel-Lindau gene, VHL, is involved in up to 60% of sporadic clear cell RCC cases, in addition to its involvement in VHL syndrome.1 von Hippel-Lindau syndrome is associated with clear cell RCC, retinal angiomas, hemangioblastomas of the central nervous system, and pheochromocytomas.¹ The mutated VHL gene is associated with an increased expression of vascular endothelial growth factor (VEGF), which promotes angiogenesis, endothelial mutagenesis, and vascular permeability.⁸ These physiologic responses are likely responsible for the proliferation and dissemination of neoplastic cells in clear cell RCC.⁹ The understanding of this pathogenic mechanism has led to the development of targeted effective treatments in RCC.

Systemic treatments for mRCC are rapidly evolving and improving.⁹ Vascular endothelial growth factor tyrosine kinase inhibitors such as sorafenib, sunitinib, and pazopanib, as well as the VEGF monoclonal antibody bevacizumab, have all demonstrated notable efficacy in the treatment of RCC. Phase 3 clinical trials for the treatment of mRCC have demonstrated that the new, more biochemically potent VEGF tyrosine kinase inhibitor axitinib has superior efficacy to sorafenib, the prior standard of care.⁹ Our patient noted that the cutaneous mRCC lesion seemed to be improving after starting treatment with axitinib 2 months prior to presentation. In addition to systemic chemotherapy, the surgical removal of lesions often is indicated for the treatment of cutaneous mRCC.^5,10 Our patient has continued axitinib and is doing well.

The Diagnosis: Epidermotropic CD8⁺ T-Cell Lymphoma

Epidermotropic CD8⁺ T-cell lymphoma is a rare aggressive form of cutaneous T-cell lymphoma (CTCL), accounting for less than 1% of all cases.¹ Since this subtype of CTCL was first described in 1999 by Berti et al,² approximately 45 cases have been reported in the literature.¹ It typically is found in elderly men and presents as disseminated or localized papules, patches, plaques, nodules, and tumors, often with central necrosis, ulceration, crusting, and hemorrhage (Figure 1).^1,3 These lesions rapidly progress and can affect any skin site, but acral accentuation and mucosal involvement are common.⁴ Due to the rapidly progressive nature of this disease, patients typically present with widespread plaque- and tumor-stage disease.³ Frequency of systemic spread is high, with metastasis to the central nervous system, lungs, and testes being most common. Lymph nodes typically are spared, helping to differentiate this form of CTCL from classic mycosis fungoides.

Diagnosis of epidermotropic CD8⁺ T-cell lymphoma is based on a combination of clinical, histopathologic, and immunohistochemical features. Histopathologic components include epidermotropism, particularly in the basal cell layer, in a pagetoid or linear pattern. A second feature is a dermal infiltrate consisting of a nodular or diffuse pattern of atypical lymphocytes that extend to the subcutaneous fat (Figure 2). All cases of epidermotropic CD8⁺ T-cell lymphoma express the CD8⁺ phenotype and most have a high Ki-67 proliferation index and are CD3, CD45RA, and/or T-cell intracellular antigen 1 positive.¹

Due to its aggressive nature, epidermotropic CD8⁺ T-cell lymphoma has a poor prognosis, with an average 5-year survival rate of 18% and median survival of 22.5 months.³ Treatment proves difficult as conventional therapies for CD4⁺ CTCL have proven ineffective for epidermotropic CD8⁺ T-cell lymphoma. Partial response has been seen with bexarotene alone and with total skin electron beam therapy combined with oral retinoids.¹

The Diagnosis: Epidermotropic CD8⁺ T-Cell Lymphoma

Epidermotropic CD8⁺ T-cell lymphoma is a rare aggressive form of cutaneous T-cell lymphoma (CTCL), accounting for less than 1% of all cases.¹ Since this subtype of CTCL was first described in 1999 by Berti et al,² approximately 45 cases have been reported in the literature.¹ It typically is found in elderly men and presents as disseminated or localized papules, patches, plaques, nodules, and tumors, often with central necrosis, ulceration, crusting, and hemorrhage (Figure 1).^1,3 These lesions rapidly progress and can affect any skin site, but acral accentuation and mucosal involvement are common.⁴ Due to the rapidly progressive nature of this disease, patients typically present with widespread plaque- and tumor-stage disease.³ Frequency of systemic spread is high, with metastasis to the central nervous system, lungs, and testes being most common. Lymph nodes typically are spared, helping to differentiate this form of CTCL from classic mycosis fungoides.

Diagnosis of epidermotropic CD8⁺ T-cell lymphoma is based on a combination of clinical, histopathologic, and immunohistochemical features. Histopathologic components include epidermotropism, particularly in the basal cell layer, in a pagetoid or linear pattern. A second feature is a dermal infiltrate consisting of a nodular or diffuse pattern of atypical lymphocytes that extend to the subcutaneous fat (Figure 2). All cases of epidermotropic CD8⁺ T-cell lymphoma express the CD8⁺ phenotype and most have a high Ki-67 proliferation index and are CD3, CD45RA, and/or T-cell intracellular antigen 1 positive.¹

Due to its aggressive nature, epidermotropic CD8⁺ T-cell lymphoma has a poor prognosis, with an average 5-year survival rate of 18% and median survival of 22.5 months.³ Treatment proves difficult as conventional therapies for CD4⁺ CTCL have proven ineffective for epidermotropic CD8⁺ T-cell lymphoma. Partial response has been seen with bexarotene alone and with total skin electron beam therapy combined with oral retinoids.¹

The Diagnosis: Epidermotropic CD8⁺ T-Cell Lymphoma

Epidermotropic CD8⁺ T-cell lymphoma is a rare aggressive form of cutaneous T-cell lymphoma (CTCL), accounting for less than 1% of all cases.¹ Since this subtype of CTCL was first described in 1999 by Berti et al,² approximately 45 cases have been reported in the literature.¹ It typically is found in elderly men and presents as disseminated or localized papules, patches, plaques, nodules, and tumors, often with central necrosis, ulceration, crusting, and hemorrhage (Figure 1).^1,3 These lesions rapidly progress and can affect any skin site, but acral accentuation and mucosal involvement are common.⁴ Due to the rapidly progressive nature of this disease, patients typically present with widespread plaque- and tumor-stage disease.³ Frequency of systemic spread is high, with metastasis to the central nervous system, lungs, and testes being most common. Lymph nodes typically are spared, helping to differentiate this form of CTCL from classic mycosis fungoides.

Diagnosis of epidermotropic CD8⁺ T-cell lymphoma is based on a combination of clinical, histopathologic, and immunohistochemical features. Histopathologic components include epidermotropism, particularly in the basal cell layer, in a pagetoid or linear pattern. A second feature is a dermal infiltrate consisting of a nodular or diffuse pattern of atypical lymphocytes that extend to the subcutaneous fat (Figure 2). All cases of epidermotropic CD8⁺ T-cell lymphoma express the CD8⁺ phenotype and most have a high Ki-67 proliferation index and are CD3, CD45RA, and/or T-cell intracellular antigen 1 positive.¹

Due to its aggressive nature, epidermotropic CD8⁺ T-cell lymphoma has a poor prognosis, with an average 5-year survival rate of 18% and median survival of 22.5 months.³ Treatment proves difficult as conventional therapies for CD4⁺ CTCL have proven ineffective for epidermotropic CD8⁺ T-cell lymphoma. Partial response has been seen with bexarotene alone and with total skin electron beam therapy combined with oral retinoids.¹

The Diagnosis: Dental Sinus Secondary to Osteonecrosis of the Jaw

Cone beam computed tomography revealed an area of lucency measuring 40×20 mm in the body of the right mandible (Figure). The patient subsequently underwent curettage of the wound with sequestrectomy of the involved area.

Osteonecrosis of the jaw is a form of avascular necrosis. It is an uncommon but potentially serious side effect of bisphosphonate use.¹ Bisphosphonates commonly are used as first-line therapy for osteoporosis, with proven efficacy to reduce fracture risk by exerting an antiresorptive effect on bones.² Bisphosphonate-related osteonecrosis of the jaw (BRONJ) is defined by the American Association of Oral and Maxillofacial Surgeons as the presence of exposed necrotic bone in the maxillofacial region that has persisted for more than 8 weeks, with current or prior treatment with a bisphosphonate and absence of prior radiation therapy to the jaw.3 Bisphosphonate-related osteonecrosis of the jaw can be associated with infections, pathologic fractures, extraoral fistulae, or osteolysis extending to the inferior border.

Our patient had a dental sinus that resulted from the underlying BRONJ. The jawbones, unlike the long bones, are in a special environment in that both acute and chronic infections occur often within the bone, and surgical procedures as well as masticatory trauma expose the bone to a bacteria-laden environment.⁴ Infection around the root apex of a tooth results in a dental abscess and a sinus tract can develop from the abscess, draining either intraorally or extraorally.⁵ Facial sinus tracts can be either odontogenic or nonodontogenic, and sometimes the lesions of dental origin may be confused with dermatological lesions.

Bisphosphonates inhibit osteoclasts, which are responsible for bone resorption. Antiangiogenetic effects also have been reported in bisphosphonates, resulting in devitalized bone.⁶ The potent and prolonged inhibition of bone remodeling likely plays an important role in BRONJ. The more frequently occurring microdamage inflicted on the lower jawbone with mastication also may represent a contributory factor.⁷

Bisphosphonate-related osteonecrosis of the jaw more often is associated with the use of high-dose intravenous (IV) bisphosphonate in cancer-related hypercalcemia and less so with oral bisphosphonates, which are generally used to treat osteoporosis.³ In a Swedish study conducted from 2003 to 2010, 55 cases of BRONJ were documented in a population of 1.2 million individuals. The prevalence of BRONJ in patients on oral bisphosphonates and IV bisphosphonates was estimated to be 0.024% and 2.8%, respectively.⁸

Bisphosphonates are widely used worldwide as the main treatment of osteoporosis. The association between osteonecrosis of the jaw and oral bisphosphonates is contentious among the osteoporosis population, as most studies focus on IV bisphosphonate use in cancer patients.⁹ Bisphosphonate-related osteonecrosis of the jaw adversely affects the patient's quality of life, producing notable morbidity in afflicted patients. Thus, a complete dental assessment and treatment is recommended before the initiation of bisphosphonate treatment. The risk for developing BRONJ associated with oral bisphosphonates increases when the duration of therapy exceeds 3 years.³ It has been reported that antifracture efficacy would persist for 1 to 2 years following discontinuation of alendronate or risedronate that had been taken for 3 to 5 years, but patients with low bone mineral density at the femoral neck (T-score below -2.5) after 3 to 5 years of treatment of bisphosphonates are at the highest risk for vertebral fractures and therefore appear to benefit most from continuation of therapy.¹⁰ For dental procedures, the American Association of Oral and Maxillofacial Surgeons suggests that if systemic conditions persist, the clinician might consider discontinuation of oral bisphosphonates for a 3-month period before and after elective invasive dental surgery to lower the risk for BRONJ.³ When possible, invasive dentoalveolar procedures such as extractions should be avoided; conservative endodontic treatment is preferable.

Bisphosphonate-related osteonecrosis of the jaw is a devastating condition that is difficult to treat and manage, thus the focus should be on prevention through dental clearance prior to starting bisphosphonates. It also is crucial to have a high index of suspicion for BRONJ in patients presenting with orofacial lesions so that they can be treated expediently.

The Diagnosis: Dental Sinus Secondary to Osteonecrosis of the Jaw

Cone beam computed tomography revealed an area of lucency measuring 40×20 mm in the body of the right mandible (Figure). The patient subsequently underwent curettage of the wound with sequestrectomy of the involved area.

Osteonecrosis of the jaw is a form of avascular necrosis. It is an uncommon but potentially serious side effect of bisphosphonate use.¹ Bisphosphonates commonly are used as first-line therapy for osteoporosis, with proven efficacy to reduce fracture risk by exerting an antiresorptive effect on bones.² Bisphosphonate-related osteonecrosis of the jaw (BRONJ) is defined by the American Association of Oral and Maxillofacial Surgeons as the presence of exposed necrotic bone in the maxillofacial region that has persisted for more than 8 weeks, with current or prior treatment with a bisphosphonate and absence of prior radiation therapy to the jaw.3 Bisphosphonate-related osteonecrosis of the jaw can be associated with infections, pathologic fractures, extraoral fistulae, or osteolysis extending to the inferior border.

Our patient had a dental sinus that resulted from the underlying BRONJ. The jawbones, unlike the long bones, are in a special environment in that both acute and chronic infections occur often within the bone, and surgical procedures as well as masticatory trauma expose the bone to a bacteria-laden environment.⁴ Infection around the root apex of a tooth results in a dental abscess and a sinus tract can develop from the abscess, draining either intraorally or extraorally.⁵ Facial sinus tracts can be either odontogenic or nonodontogenic, and sometimes the lesions of dental origin may be confused with dermatological lesions.

Bisphosphonates inhibit osteoclasts, which are responsible for bone resorption. Antiangiogenetic effects also have been reported in bisphosphonates, resulting in devitalized bone.⁶ The potent and prolonged inhibition of bone remodeling likely plays an important role in BRONJ. The more frequently occurring microdamage inflicted on the lower jawbone with mastication also may represent a contributory factor.⁷

Bisphosphonate-related osteonecrosis of the jaw more often is associated with the use of high-dose intravenous (IV) bisphosphonate in cancer-related hypercalcemia and less so with oral bisphosphonates, which are generally used to treat osteoporosis.³ In a Swedish study conducted from 2003 to 2010, 55 cases of BRONJ were documented in a population of 1.2 million individuals. The prevalence of BRONJ in patients on oral bisphosphonates and IV bisphosphonates was estimated to be 0.024% and 2.8%, respectively.⁸

Bisphosphonates are widely used worldwide as the main treatment of osteoporosis. The association between osteonecrosis of the jaw and oral bisphosphonates is contentious among the osteoporosis population, as most studies focus on IV bisphosphonate use in cancer patients.⁹ Bisphosphonate-related osteonecrosis of the jaw adversely affects the patient's quality of life, producing notable morbidity in afflicted patients. Thus, a complete dental assessment and treatment is recommended before the initiation of bisphosphonate treatment. The risk for developing BRONJ associated with oral bisphosphonates increases when the duration of therapy exceeds 3 years.³ It has been reported that antifracture efficacy would persist for 1 to 2 years following discontinuation of alendronate or risedronate that had been taken for 3 to 5 years, but patients with low bone mineral density at the femoral neck (T-score below -2.5) after 3 to 5 years of treatment of bisphosphonates are at the highest risk for vertebral fractures and therefore appear to benefit most from continuation of therapy.¹⁰ For dental procedures, the American Association of Oral and Maxillofacial Surgeons suggests that if systemic conditions persist, the clinician might consider discontinuation of oral bisphosphonates for a 3-month period before and after elective invasive dental surgery to lower the risk for BRONJ.³ When possible, invasive dentoalveolar procedures such as extractions should be avoided; conservative endodontic treatment is preferable.

Bisphosphonate-related osteonecrosis of the jaw is a devastating condition that is difficult to treat and manage, thus the focus should be on prevention through dental clearance prior to starting bisphosphonates. It also is crucial to have a high index of suspicion for BRONJ in patients presenting with orofacial lesions so that they can be treated expediently.

The Diagnosis: Dental Sinus Secondary to Osteonecrosis of the Jaw

Cone beam computed tomography revealed an area of lucency measuring 40×20 mm in the body of the right mandible (Figure). The patient subsequently underwent curettage of the wound with sequestrectomy of the involved area.

Osteonecrosis of the jaw is a form of avascular necrosis. It is an uncommon but potentially serious side effect of bisphosphonate use.¹ Bisphosphonates commonly are used as first-line therapy for osteoporosis, with proven efficacy to reduce fracture risk by exerting an antiresorptive effect on bones.² Bisphosphonate-related osteonecrosis of the jaw (BRONJ) is defined by the American Association of Oral and Maxillofacial Surgeons as the presence of exposed necrotic bone in the maxillofacial region that has persisted for more than 8 weeks, with current or prior treatment with a bisphosphonate and absence of prior radiation therapy to the jaw.3 Bisphosphonate-related osteonecrosis of the jaw can be associated with infections, pathologic fractures, extraoral fistulae, or osteolysis extending to the inferior border.

Our patient had a dental sinus that resulted from the underlying BRONJ. The jawbones, unlike the long bones, are in a special environment in that both acute and chronic infections occur often within the bone, and surgical procedures as well as masticatory trauma expose the bone to a bacteria-laden environment.⁴ Infection around the root apex of a tooth results in a dental abscess and a sinus tract can develop from the abscess, draining either intraorally or extraorally.⁵ Facial sinus tracts can be either odontogenic or nonodontogenic, and sometimes the lesions of dental origin may be confused with dermatological lesions.

Bisphosphonates inhibit osteoclasts, which are responsible for bone resorption. Antiangiogenetic effects also have been reported in bisphosphonates, resulting in devitalized bone.⁶ The potent and prolonged inhibition of bone remodeling likely plays an important role in BRONJ. The more frequently occurring microdamage inflicted on the lower jawbone with mastication also may represent a contributory factor.⁷

Bisphosphonate-related osteonecrosis of the jaw more often is associated with the use of high-dose intravenous (IV) bisphosphonate in cancer-related hypercalcemia and less so with oral bisphosphonates, which are generally used to treat osteoporosis.³ In a Swedish study conducted from 2003 to 2010, 55 cases of BRONJ were documented in a population of 1.2 million individuals. The prevalence of BRONJ in patients on oral bisphosphonates and IV bisphosphonates was estimated to be 0.024% and 2.8%, respectively.⁸

Bisphosphonates are widely used worldwide as the main treatment of osteoporosis. The association between osteonecrosis of the jaw and oral bisphosphonates is contentious among the osteoporosis population, as most studies focus on IV bisphosphonate use in cancer patients.⁹ Bisphosphonate-related osteonecrosis of the jaw adversely affects the patient's quality of life, producing notable morbidity in afflicted patients. Thus, a complete dental assessment and treatment is recommended before the initiation of bisphosphonate treatment. The risk for developing BRONJ associated with oral bisphosphonates increases when the duration of therapy exceeds 3 years.³ It has been reported that antifracture efficacy would persist for 1 to 2 years following discontinuation of alendronate or risedronate that had been taken for 3 to 5 years, but patients with low bone mineral density at the femoral neck (T-score below -2.5) after 3 to 5 years of treatment of bisphosphonates are at the highest risk for vertebral fractures and therefore appear to benefit most from continuation of therapy.¹⁰ For dental procedures, the American Association of Oral and Maxillofacial Surgeons suggests that if systemic conditions persist, the clinician might consider discontinuation of oral bisphosphonates for a 3-month period before and after elective invasive dental surgery to lower the risk for BRONJ.³ When possible, invasive dentoalveolar procedures such as extractions should be avoided; conservative endodontic treatment is preferable.

Bisphosphonate-related osteonecrosis of the jaw is a devastating condition that is difficult to treat and manage, thus the focus should be on prevention through dental clearance prior to starting bisphosphonates. It also is crucial to have a high index of suspicion for BRONJ in patients presenting with orofacial lesions so that they can be treated expediently.