Subcutaneous granuloma annulare following herpes zoster

Abstract

A 57‐year‐old Korean man developed a papulovesicular eruption on the right chest with unilateral T2 dermatomal distribution; acute herpes zoster (HZ) was diagnosed. The past medical history revealed diabetes mellitus, but was otherwise noncontributory. His pain gradually subsided with treatment in the Pain Clinic of the Anesthesiology Department. Five months later, however, new skin lesions composed of several papules were detected at the site of the HZ scar. There were several discrete, nontender, firm, erythematous papules of about 0.8 cm in diameter on the right chest ( Fig. 1 ). Histologic examination revealed foci of necrobiotic collagen surrounded by a vague palisade of histiocytes in the deep dermis and subcutis ( Fig. 2 ). Mucin deposits were seen within the center of the palisaded granuloma and there were scattered multinucleated giant cells. Gram, Gomeri‐methenamine silver, and acid‐fast stains were negative. Polarizing microscopy did not reveal any material. Subcutaneous granuloma annulare at the HZ scar was diagnosed, and intralesional injections of triamcinolone caused flattening of the papules after 4 weeks of follow‐up. Skin examination revealed several discrete, nontender, firm, erythematous papules of about 0.8 cm in diameter on the right upper chest (T2 dermatome) image Histologic examination revealed foci of necrobiotic collagen surrounded by a vague palisade of histiocytes in the deep dermis and subcutis. Scattered multinucleated giant cells were seen (hematoxylin and eosin; original magnification, ×100) image