A 5-year-old African American boy was brought to the office by his parents, who noticed skin lesions on the boy’s trunk and arm. The child was otherwise healthy, and physical examination findings were normal.
This child has lichen nitidus, a relatively uncommon benign dermatosis of unknown etiology seen mostly in preschool- and school-aged children. It is characterized by papular, flat-topped, uniform, shiny, slightly elevated lesions. The lesions measure 1 to 2 mm in size and appear in groups, primarily on the trunk, abdomen, genitals, and forearms. Lesions appearing on lines of trauma (the Koebner phenomenon) are common. The rash may be generalized in black children, in whom lesions typically are hypopigmented.
The course is variable, but lichen nitidus frequently lasts weeks to several months before clearing, with little or no response to treatment. Oral antihistamines or topical corticosteroids may be helpful in some cases. Patients usually are otherwise asymptomatic and do well constitutionally.
Associations with lichen planus, atopic dermatitis, and nail changes have been reported, as have familial cases of lichen nitidus. Widespread keratosis pilaris is differentiated from lichen nitidus in part by the absence of Koebner phenomenon.
Deepak M. Kamat, MD, PhD—Series Editor:Dr Kamat is professor of pediatrics at Wayne State University in Detroit. He is also director of the Institute of Medical Education and vice chair of education at Children’s Hospital of Michigan, both in Detroit.