Nail changes associated with pigmentary disorders

Abstract

Salient nail unit changes serve as pointers toward systemic disease. On similar lines, salient nail changes are associated with pigmentary disorders, and can help toward diagnosis. Nail changes form a part of various physiologic pigmentary changes including racial pigmentation, pregnancy, or neonatal period. At the same time, a number of nail changes can be valuable clues toward disorders of pigmentation associated with genetic syndromes (Laugier–Hunziker syndrome, incontinentia pigmenti, and tuberous sclerosis), endocrine disorders, disorders of metabolism (alkaptonuria), infections (HIV-AIDS), internal malignancies, etc. Nail changes are especially useful if cutaneous pigmentary changes are suspected to be drug-induced based or associated mucosal and/or cutaneous hyperpigmentation. Various drugs that can cause cutaneous pigmentary alterations along with nail changes include cyclophosphamide, adriamycin, vincristine, docetaxel, paclitaxel, carboplatin, psoralens, hydroxyurea, bleomycin, etc. Nail changes are also associated with disorders of hypomelanosis, for example, vitiligo. Pigmentary changes due to endogenous and exogenous pigments are again diagnosable based on the nail changes they induce. This narrative review highlights the importance of nail changes in suspecting and diagnosing various disorders of pigmentation. It also points toward areas which need future research.