Genodermatosis with reticulate, patchy and mottled pigmentation of the neck--a clue to rare dermatologic disorders.

Reticulate pigmentation of the neck is a common finding in numerous genodermatoses and acquired diseases. As the neck is readily accessible to medical inspection, it may serve as a diagnostic window for various dermatoses. Several entities out of the spectrum of ectodermal dysplasia present with reticulate or mottled pigmentation on the upper trunk and neck. The most impressive genodermatoses with punctate and reticulate pigmentation affecting the neck are the Naegeli-Franceschetti-Jadassohn syndrome, dermatopathia pigmentosa reticularis and dyskeratosis congenita. Reticulate pigmented anomaly of the flexures and lentiginosis, disorders of cornification and related entities are further genodermatoses which may involve the neck. In our review we have integrated inherited dermatoses which do not obligatorily affect the neck but have been well documented to do so. Our work should give the clinician a checklist on genodermatoses which may produce reticulate and mottled pigmentation on the neck.