Dyshidrosiform Bullous Pemphigoid: Case Reports and Review.

Bullous pemphigoid is an autoimmune blistering disorder that typically presents in elderly patients as pruritic tense subepidermal blisters on the lower trunk, axilla, and groin. It is caused by circulating and tissue-bound autoantibodies directed against bullous pemphigoid antigen 1 or bullous pemphigoid antigen 2 or both. Dyshidrosiform bullous pemphigoid is a rare variant of bullous pemphigoid, and it usually presents as itchy, potentially hemorrhagic, or purpuric blisters on the palms and/or soles of elderly individuals; subsequently, typical bullous lesions of bullous pemphigoid appear on other body sites. In our study, we report the features of two men with dyshidrosiform bullous pemphigoid and review the characteristics of individuals with this rare subtype of bullous pemphigoid. Including the men whose condition is described in this paper, at least 72 patients with dyshidrosiform bullous pemphigoid have been reported so far. However, complete features of the condition have not been described for all of the individuals. Based on the cases reported so far, the condition was slightly more common in women and the onset of the disease, for most of the patients, occurred between the ages of 61 and 94 years. The patients usually presented with blisters on both their palms and soles (66%) or just their soles (31%); 77% of the patients had progression of bullous pemphigoid to other areas of their body. Whether hemorrhagic blisters or purpuric lesions are associated with dyshidrosiform bullous pemphigoid remains to be determined; these features were present in 91% of the 22 patients who were described in the case reports yet were only observed in 5% of the individuals from a single larger series of 20 patients. The mainstay of therapy for dyshidrosiform bullous pemphigoid is systemic corticosteroids, with or without topical corticosteroids, and/or systemic dapsone or immunosuppressants; nearly all of the patients showed improvement after the treatment was initiated. Similar to individuals with bullous pemphigoid, at least nine of the dyshidrosiform bullous pemphigoid patients, including both patients in this report, had either a neurologic condition (seven patients) or both a neurologic condition and a psychiatric disorder (two patients). Usually, an autoimmune bullous disease, particularly dyshidrosiform bullous pemphigoid, is not initially considered in patients who present with blisters restricted to the palms and/or soles. Indeed, the lesion morphology of dyshidrosiform bullous pemphigoid mimics several other conditions that are characterized by blisters on the hands and feet, such as allergic and irritant contact dermatitis, chronic bullous disease of childhood, cutaneous T-cell lymphoma, dermatophyte infection, dyshidrosis or pompholyx, epidermolysis bullosa acquisita, erythema multiforme, herpes gestationis, lichen planus, linear IgA disease, scabies, and systemic contact dermatitis. In conclusion, the possibility of dyshidrosiform bullous pemphigoid should be considered in elderly individuals who present with the new onset of palmar and/or plantar blisters that are either recurrent or recalcitrant to therapy or would subsequently also appear on other areas of the body.