Linear and Whorled Nevoid Hypermelanosis

Image and content excerpted from the VisualDx clinical decision support system.

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ICD-9 Codes

757.33 – Congenital pigmentary anomalies of skin

Synopsis

Linear and whorled nevoid hypermelanosis is a sporadic disorder of asymmetric hyperpigmentation in a streaky or swirl-like pattern. It is also referred to as pigmentary mosaicism. The hyperpigmentation is present at birth or within the first few weeks of life and is not preceded by any other eruptions in the skin. The pigmentation may become more evident over the first few years of life, then stabilizes, and only rarely fades.
In the minority of cases, associated anomalies have been detected involving the central nervous and musculoskeletal systems as well as ocular and other abnormalities.
This disorder most likely represents a mosaic population of neuroectodermal cells, resulting in 2 distinct populations of skin cells having different colors.

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