Unilateral Heterochromia of Scalp Hair with Adjacent Hypomelanotic Skin Lesions

An eight-year-old white boy exhibited unilateral heterochromia of the scalp hair, characterized by blond hair patches in the right parieto-occipital and temporal regions, alongside adjacent hypomelanotic skin lesions. This condition, present since his first year of life, suggested a disorder of pigmentation potentially linked to pigmentary mosaicism, as it followed Blaschko's lines. Such asymmetric heterochromia was considered a pigmentation disorder, contrasting with symmetrical heterochromia, which could be a normal physiological process.