Pemphigus foliaceus masquerading as IgA pemphigus and responding to dapsone

Area of Science:

• Dermatology
• Autoimmune Blistering Diseases
• Immunodermatology

Background:

• Pemphigus foliaceus is a chronic autoimmune blistering disease.
• It typically presents with superficial erosions and crusting, often in a seborrheic distribution.
• Diagnostic challenges arise with atypical presentations or overlapping features with other pemphigus variants.

Purpose of the Study:

• To report a unique case of pemphigus foliaceus mimicking IgA pemphigus.
• To discuss diagnostic considerations and treatment strategies for challenging pemphigus cases.
• To highlight the response to dapsone in a patient with confirmed pemphigus foliaceus.

Main Methods:

• Clinical presentation and dermatological examination of a 14-year-old male with a seven-year history of skin lesions.
• Histopathological examination and direct immunofluorescence of skin biopsies.
• Treatment with dexamethasone pulse therapy, followed by dapsone.
• Enzyme-linked immunosorbent assay (ELISA) for anti-desmoglein 1 antibodies.

Main Results:

• Initial presentation included recurrent fluid-filled, itchy, eroded lesions unresponsive to corticosteroids and azathioprine.
• Histopathology and direct immunofluorescence were characteristic of pemphigus foliaceus.
• Dexamethasone pulse therapy showed inadequate response.
• Relapsing lesions exhibited a circinate arrangement, suggesting IgA pemphigus.
• Dapsone treatment resulted in dramatic improvement within four weeks.
• Repeat biopsy confirmed pemphigus foliaceus, and ELISA was positive for anti-desmoglein 1 antibodies.

Conclusions:

• Pemphigus foliaceus can present with features mimicking other autoimmune blistering diseases, such as IgA pemphigus.
• Dapsone can be an effective treatment option for recalcitrant pemphigus foliaceus.
• Thorough diagnostic evaluation, including repeat biopsies and serological testing, is crucial for accurate diagnosis and management of autoimmune blistering conditions.