Oral hyperpigmentation in HIV-infected patients.

Six cases of oral hyperpigmentation in HIV-infected patients are reported. While in two patients the lesions could be related to systemic clofazimine or ketoconazole therapy, in the other patients the cause remained unknown. Clinically, the pigmentations were characterized by a sudden onset and the appearance of well-defined, brown-black macules in the buccal mucosa, the gingiva, the hard palate, or the lateral borders of the tongue. In one patient, longitudinal hyperpigmented striae were observed on all fingernails and toenails. Histologically, hyperpigmentations associated with systemic medication revealed accumulation of melanin in phagocytes and extracellularly within the connective tissue. In those lesions with unknown cause, melanin was restricted to keratinocytes of the basal cell layer or to extracellular foci in the lamina propria. The clinical and histologic findings, as well as differential diagnosis, are discussed.