Exophytic plaques, blisters, and mouth ulcers. Pemphigus vegetans (PV), Neumann type.

A 36-year-old woman presented with a painful and pruritic eruption on both feet. She had a history of asthma, allergic rhinitis, and chronic sinusitis and had been treated atvarioustimeswithfexofenadinehydrochloride,mometasone furoate nasal spray, hydroxyzine hydrochloride, diphenhydramine hydrochloride, albuterol sulfate, montelukast sodium, fluticasone propionate, and salmeterol inhalation powder. She reported intermittent episodes of unilateral lower leg edema associated with pruritus, which had been treated with diphenhydramine in the past. The physical examination showed lower extremity swelling with retiform erythematous and hyperpigmented patches with central vesiculation limited to the dorsal feet (Figure1). Dorsalis pedis pulses were present. Initial laboratory studies revealed an elevated white blood cell (WBC) count of 14 900 cells/μL with 47% eosinophilia. The erythrocyte sedimentation rate was 92 mm/h, and the alkaline phosphatase level was 320 U/L. (To convert WBC count to cells 10 per liter, multiply by 0.001. To convert alkaline phosphatase to microkatals per liter, multiply by 0.0167.) A punch biopsy sample was taken from the right dorsal foot (Figure 2 and Figure 3) What is your diagnosis?