Annular lichenoid dermatitis of youth (ALDY) is a rare annular dermatosis that is most frequently encountered in children. It presents as one or more asymptomatic, well-demarcated, erythematous patches that evolve into annular plaques with raised erythematous borders and central hypopigmentation. Sites of predilection are the flank, groin, and abdomen. While lesions are typically asymptomatic, cases of associated pruritus have been reported. The disease typically follows a chronic course and frequently recurs, especially after discontinuation of treatment.

The condition was described initially in children and young adults. The median age of onset is approximately 10 years. However, cases of annular lichenoid dermatitis have also been described in adult patients, and the disease has been seen in patients ranging from 1-45 years of age. Male and female patients are equally affected. While most cases described are from Mediterranean countries, several cases from the United States, Japan, and Europe have also been reported.

Only approximately 50 cases of ALDY have been reported in the literature. However, it is unclear if the prevalence of ALDY is low or if the condition is underreported.

While the etiology of ALDY is still undetermined, several case reports have suggested a possible association with Borrelia infection, hepatitis B vaccination, and contact dermatitis. Immunohistochemical studies demonstrate a T-cell mediated immune reaction, similar to other lichenoid diseases.