Xcix. Histopathology of the Skin in Pellagra

Pellagra and skin

“…The initial cutaneous lesions of pellagra consist of an inflammatory reaction, which may or may not be accompanied by the formation of vesicles or bullae. This pathologic process resembles eczema 38 . The upper half of the stratum malpighi shows marked vacuolar change in the early stages 39 .…”

“…If this vacuolar change is marked, a cleft may form in the upper epidermis, correlating with the blistering seen in wet pellagra 40 . This stage is followed by hyperplasia of the epidermis (acanthosis), with hyperkeratosis, and increased pigment throughout the layers of the epidermis 38 . Pigment granules are even found in the stratum corneum.…”

“…The end‐stage of the process is atrophy of the epidermis with flattening of the rete ridges and fibrosis of the cutis 38 . The sebaceous glands may become atrophic.…”

Dark-violaceous lesions on the dorsa of both hands

“…In older lesions, hyperkeratosis or irregular epidermal hyperplasia is observed. 5 In our patient, the rash was localized to the dorsa of both hands, and he had no other symptoms. Furthermore, other than the subtotal gastric resection, he had no major risk factors for pellagra, such as oral administration of the aforementioned drug, fatty diet, chronic alcohol drinking or IBD.…”

“…The histological changes in the skin are nonspecific; the upper dermis shows superficial perivascular lymphocytic inflammatory infiltrates in the early stage, and there may sometimes be vesicles owing to vacuolar degeneration of the basal layer. In older lesions, hyperkeratosis or irregular epidermal hyperplasia is observed …”