Value of the Scraping Test in a Case of Exogenous Henna-Induced Pigmentation Mimicking Acral Melanoma

We report the case of a 70-year-old woman hospitalized for erysipelas of the lower limbs, in whom an acral pigmented lesion was incidentally discovered during clinical examination. Dermoscopic evaluation revealed a parallel ridge pattern, raising strong suspicion of acral melanoma. In view of this suspicion, a biopsy-excision was considered. However, a simple superficial scraping test using a scalpel blade completely removed the pigmentation, pointing towards an exogenous origin. A detailed patient history subsequently revealed that henna had been applied approximately four months earlier. This case highlights the importance of combining dermoscopy, non-invasive tests, and thorough anamnesis to establish an accurate differential diagnosis of acral pigmented lesions.