Pemphigus herpetiformis in South Tunisia: a clinical expression of pemphigus foliaceus?

BACKGROUND:Pemphigus herpetiformis (PH) is a rare subtype of pemphigus combining clinical features of dermatitis herpetiformis and the immunopathologic characteristics of pemphigus. We aimed to analyze the epidemiological, clinical, and immunological presentation and management of the disease in a cohort of south Tunisian patients with a long-term follow-up. METHODS:We included all patients with confirmed PH followed from January 1987 to December 2015 in the dermatology department. RESULTS:We included 24 south Tunisian female patients with a mean age of 36 years (20-63), mainly from rural origin (84%). All patients had exclusive skin lesions. Clinical features combined erythematous, vesicular, or bullous lesions, with circinate borders mainly on the trunk and limbs associated with severe pruritus (91%). Peripheral hypereosinophilia was noted in 31% of cases. Histological examination demonstrated no intraepithelial (50%), suprabasal (35%), or subcorneal cleavage (15%). Eosinophilic spongiosis was seen in 42% of cases. On direct immunofluorescence, there was an intercellular staining in 96% of cases composed mainly of IgG and C3 (79%). Indirect immunofluorescence was positive in 71% of cases. Reactivity was mainly directed against Dsg1. Dapsone alone was inefficient. All patients received systemic corticosteroids. Most patients (64%) relapsed. Iatrogenic complications and cutaneous infections were noted in 40% and 16% of cases, respectively. CONCLUSION:PH is characterized by the occurrence of exclusive skin lesions in young women with a good response to corticosteroids but not to Dapsone. Reactivity mainly against Dsg1 suggests that PH in south Tunisia is a particular variant of nonendemic pemphigus foliaceus.