REPORT OF A CASE
A 53-year-old man presented with a 4-year history of pruritic lesions, mostly on his extremities. History revealed hypothyroidism treated with thyroxine (Eltroxin) for more than 10 years.Cutaneous examination revealed red-to-vio-laceous lichenoid papules and plaques, arranged in a linear and reticular pattern on the flexor aspects of his forearms and on the lateral aspects of his abdomen and thighs (Figure 1). On the buttocks were numerous small follicular papules (Figure 2). The mucous membranes and nails were not affected. The rest of the physical examination was unremarkable.Routine laboratory examinations, including erythrocyte sedimentation rate, complete blood cell count, automated analysis system profile (ie, SMA), and urinalysis, were all within normal limits. There was no laboratory evidence of immune deficiency.A skin biopsy specimen was obtained from a lichenoid papule (Figure 3).What is your diagnosis?
Keratosis lichenoides chronica.
Amichai B, Grunwald MH, Halevy S. Violaceous Papules in a Linear and Reticular Pattern. Arch Dermatol. 1995;131(5):611-612. doi:10.1001/archderm.1995.01690170113019