PMC5437479_01
a Plaque with overlying crusts and annular pustules on erythematous ground on the fourth right digit. b Histopathology revealed prominent acanthosis with an intraepidermal eosinophilic pustule accompanied by surrounding eosinophilic spongiosis and a superficial eosinophil-rich inflammatory infiltrate and acantholysis. c Direct IF microscopy of perilesional skin showing intercellular deposits of IgG antibodies in the epidermis. IF, immunofluorescence.
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F1
Physical examination revealed a plaque with overlying crusts and annular pustules on erythematous ground on the fourth right digit (Fig. 1a). Histopathology showed eosinophilic pustule formation in the epidermis in concert with acantholysis and a superficial eosinophil-rich lymphocytic infiltrate (Fig. 1b) reminiscent of PVeg. IF microscopy of perilesional skin revealing intercellular deposits of IgG antibodies in the epidermis (Fig. 1c). Indirect IF microscopy on monkey esophagus allowed detection of IgG antibodies binding with an intercellular pattern.
Serum autoantibody levels during the course of the disease. Black dots indicate the level of anti-Dsg3 antibodies. White squares indicate the level of anti-Dsg1 antibodies. Adjuvant treatment consisted of azathioprine or mycophenolate mofetil. Each solid-lined black arrow indicates a steroid pulse (100 mg dexamethasone on 3 consecutive days). The dashed arrows refer to rituximab administration (1 g). Disease activity is indicated by gray arrows. AZA, adjuvant treatment consisted of azathioprine.
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F2
Two weeks after the second intravenous steroid pulse, anti-Dsg3 antibody levels notably decreased to 237 U/mL (Fig. 2), and the patient was almost free of skin lesions. Worsening of disease was reflected by an increase of serum autoantibody levels (anti-Dsg3 IgG: 3,328 U/mL; anti-Dsg1 IgG: 30 U/mL) (Fig. 2).