Blue-red macules and pseudoatrophic macules: additional cutaneous signs in neurofibromatosis.

Blue-red macules and pseudoatrophic macules are characteristic skin lesions of neurofibromatosis that have been infrequently mentioned in the recent literature. The histologic characteristics of the blue-red macules show thick-walled blood vessels located mainly in the papillary dermis and often overlying subcutaneous neurofibromatous tissue. The histologic characteristics of the pseudoatrophic macules show a reduction in collagen in the reticular dermis, with diffuse replacement by neuroid tissue. These clinical signs can be detected early in the course of the disease and are useful in establishing an early diagnosis.