Linear And Whorled Nevoid Hypermelanosis

Linear and whorled nevoid hypermelanosis (LWNH) is a rare benign condition affecting skin pigment occurring in newborns or early infancy.  The primary symptom is swirling streaks of darkened (hyperpigmented) skin, mainly on the trunk and limbs. The dark streaks appear along the lines of normal skin development (lines of Blaschko). LWNH typically spreads for one to two years and then becomes stable. The dark streaks sometimes fade with age. Most of the time, only the skin is affected, but other conditions, such as growth, developmental, or heart problems may be present. The cause for LWNH is unknown. Genetic factors, especially chromosomal mosaicism, may be involved. LWNH is not thought to be inherited. It is diagnosed based on the symptoms. There is no specific treatment for the skin findings in LWNH because they are not associated with any medical problem.