The lesions on this 15-year-old boy’s left lower extremity have been present for years and are asymptomatic. They have slowly progressed over the years.
Results of a biopsy confirmed the diagnosis of lichen aureus. Lichen aureus is an uncommon subtype of benign pigmented purpura. Clinically characterized by rust macules, papules, or plaques, it is a chronic disease that more often affects young adults and is localized mainly to one or both lower extremities. When multiple lesions are present, they can appear segmental or dermatomal, as seen in this patients’ case. Treatment can be challenging, since lichen aureus often does not respond to topical corticosteroids; however, no treatment is necessary. The condition can last months to years.
Warts would have a more verrucous appearance without the purpura. Lichen planus lesions are purplish, polygonal papules that could mimic lichen aureus. Linear epidermal nevus can be acquired, but lesions would be more wart-like in appearance. The skin texture change argues against trauma in this case. The absence of scale and the presence of purpura argues against a diagnosis of psoriasis.
David L. Kaplan, MD, is a clinical assistant professor of dermatology at the University of Missouri–Kansas City School of Medicine in Kansas City, Missouri, and at the University of Kansas School of Medicine in Kansas City, Kansas. He practices adult and pediatric dermatology in Overland Park, Kansas.