Pigmentary nail changes may have a variety of causes, e. g., chronic inflammation, and occur more often in patients of African descent compared to Caucasians. Subungual malignant melanoma is the most important differential diagnosis and must be ruled out in any case. Dermatoscopy might be helpful. If no biopsy is taken, clinical follow-ups are necessary at short intervals. In case of chronic paronychia, optimization of occupational skin protection measures may contribute to the healing process.
Keywords: Biopsy; Dermatoscopy; Hutchinson sign; Melanonychia; Subungual malignant melanoma.