Becker's nevus

A Becker nevus (also melanosis naeviformis, Becker melanosis, Becker's pigmentary hamartoma or Nevoid melanosis ) is a single, large, irregular brown colored skin patch (hyperpigmentation ), which is covered with dense hair from puberty ( hypertrichosis ) .. It is to be a specific subtype of benign pigmented, limited malformations of the skin ( pigmented nevi ), colloquially " birthmarks " or " liver spots".

Epidemiology

About the Becker nevus are relatively few scientific papers. It is therefore assumed that this entity is not yet fully explored in terms of frequency and course. It mainly affects men of the first signs of skin changes usually begin before puberty or during adolescence.

The most comprehensive study on the subject is a study from 1981, in which 20,000 young Frenchmen were screened. In this work, there was a prevalence of 0.52 %. In half of the patients, the Becker nevus showed in the first decade of life, the other half in the second decade of life ( ages 11 to 20). Also noticeable was the fact that only 32% of Becker nevi apply above the nipples of the present investigation. This result was to hitherto existing considers Becker nevi träten on especially in the area of the chest and shoulders.

Clinic

Typically, a palm-sized, sharp and jagged limited, irregular hyperpigmented Einzelläsion forms in the region of the back or shoulders. First, the lesion is still smooth or roughened slightly, within a year then is added an increased hair growth.

In contrast to melanocytic nevi here find any Nävuszellnester or increased melanocytes, but only an increased formation of melanin as a cause of hyperpigmentation.

Course and prognosis

A Becker nevus usually occurs spontaneously, before puberty normally. Than hairless golden brown to light brown, sometimes mottled coloration of the skin Rarely, at a later Pale of Becker nevus. Increased hair growth occurs only after completing pigmentation in pubertal and postpubertal patients.

Up to the visual aspects of the Becker nevus is always safe and presents no risk for developing melanoma dar. He is, however, distinguished from a potentially dangerous congenital nevus that is present at birth, usually in contrast to Becker nevus. However, there are in the literature, case reports of congenital ( already applied at birth) Becker nevi. A final differential diagnosis can therefore only be performed by a dermatologist or Dematohistopathologen.

Treatment

Different types of laser treatments can help to reduce or eliminate hyperpigmentation. However, this should only be done after an assessment by a dermatologist because other less harmless pigment changes can mimic the image of a Becker nevus. The results of treatment in both the hair and the pigment removal are very different, so that also can not make any general statements.