Two Features of Annular Lichenoid Dermatitis of Youth (ALDY).

A healthy 14-year-old boy presented with a 2-month history of two slowly expanding asymptomatic lesions on his right trunk. No etymology of any new medications, recent travel, or tick bites was reported. Physical examination demonstrated two 4.5×2.5- cm and 3.5×2-cm annular hyperpigmented plaques with slightly elicited red borders on the right lower abdomen and right inferior flank. No evidence of atrophy or sclerosis was noted (Figure 1A). A 4-mm punch biopsy revealed irregular epidermal hyperplasia with alteration of thinned and quadrangular rete ridges, a dense band-like lichenoid infiltrate in the papillary dermis admixed with numerous melanophages and occasional necrotic keratinocytes. No evidence of epidermotropism was observed (Figure 1B). The dermal infiltrate was predominantly composed of CD3+ T-lymphocytes admixed with rare CD20+ B-lymphocytes and increased CD8-CD4 ratio. The patient showed significant improvement following the application of a potent steroid ointment for several weeks.