What nail changes are considered peculiar to human immunodeficiency virus (HIV) infection?

Patients with acquired immune deficiency syndrome may develop acromelanosis, in which hyperpigmented macules occur on the fingers, palms, soles, and nails. In the nails, they appear as longitudinal pigmentary bands (melanonychia). Hence, melanonychia of several nails with skin hyperpigmentation is a strong clue to HIV infection. Commonly, nail pigmentation is seen with the drug zidovudine. Proximal subungual onychomycosis and candidal onychomycosis are also considered a marker for HIV infection. Long-standing, treatmentresistant, periungual warts are common, and progression to squamous cell carcinoma is a distinct possibility.