Background
Becker melanosis was described in 1948 by S. William Becker in two young men with acquired melanosis and hypertrichosis in a unilateral distribution. [1] Since then, this condition has been termed Becker nevus.
Pathophysiology
The pathogenesis and etiology of Becker nevus remain uncertain.
Androgens may play a role in Becker melanosis, as evidenced by its peripubertal development, male preponderance, hypertrichosis, occasional development of acneform lesions within the patch, and rare association with accessory scrotum in the genital region. In addition, a significant increase in the number of androgen receptors in Becker melanosis lesional skin has been reported. [2]
Epidemiology
Frequency
A study of 19,302 men aged 17-26 years revealed a prevalence of Becker melanosis of 0.52%.
Sex
Males are affected by Becker melanosis more often than females.
Age
Although Becker nevus usually is a sporadic condition that manifests in the peripubertal period, both congenital and familial cases [3] have been described.
Patient Education
Advise patients that Becker melanosis is a benign entity and does not require treatment except for cosmetic reasons.
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Becker nevus of chest wall with associated hypertrichosis. Courtesy of Jason K. Rivers, MD.
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Becker nevus demonstrating smooth muscle bundles in the dermis. Courtesy of Jason K. Rivers, MD.