Background: Annular lichenoid dermatitis of youth (ALDY) is an uncommon disease clinically reminiscent of morphea, annular erythema or mycosis fungoides. Objective: To describe the histological and clinical features of a small series of patients with ALDY and to review the literature. Patients: We describe the clinical and histological features of six patients (age range 7-79 years) with asymptomatic erythematous macules and patches with a red-brownish border and central hypopigmentation, mostly distributed on the groin and flanks. Histologically, all cases showed lichenoid dermatitis limited to the tips of rete ridges, with many intraepidermal CD8+ and some CD4+ T cells. T cell receptor rearrangement was absent in all cases. A total of 44 patients with a consistent clinical and histological picture have been described. The disease is sensitive to topical and/or systemic corticosteroids. Conclusions: ALDY is a unique lichenoid dermatitis for whose diagnosis a clinical-pathological correlation is essential. The disease typically affects young patients, more rarely adults and elderly.