PMC7270598_01
A) Violaceous, targetoid plaque with central necrosis and peripheral rim of erythema on the dorsal second digit of the right hand just proximal to the proximal interphalangeal joint. B) Violaceous, smooth, dome-shaped nodule with central dusky blue hue and fissure as well as peripheral rim of erythema on the dorsal fifth digit of the right hand overlying the distal interphalangeal joint. C) Edematous periungal plaque with dull erythema at the junction of the proximal and lateral nail folds of fourth digit of the left hand. D) Thin erythematous periungal plaque with fine collarette of scale on the proximal and lateral nail folds and skin overlying the distal interphalangeal joint of the fourth digit of the left hand. This image was taken fifteen days later, when the lesions were healing in the regression stage. (For interpretation of the references to colour in this figure legend, the reader is referred to the web version of this article).
gr1.jpg
PMC7270598_01_gr1.jpg
fig0005
On his left hand the patient was noted to have an edematous, periungual plaque with dull erythema at the junction of the proximal and lateral nail folds of the fourth digit (Fig. 1). At a follow-up appointment 15 days later, his lesions had significantly improved, with resolution of swelling and pain (Fig. 1, Panel D).
Biopsy reveals prominent dermal edema with subepidermal blister formation (arrowhead), necrosis of the dermis (arrow), scattered perivascular and interstitial neutrophil infiltrate (asterisk), vascular dilation, and inclusion bodies with vacuolated keratinocytes (circle, magnified in bottom right) (Hematoxylin-eosin stain; original magnification 100x).
gr2.jpg
PMC7270598_01_gr2.jpg
fig0010
Histopathology showed neutrophilic infiltrates and inclusion bodies within vacuolated keratinocytes (Fig. 2).