The first report of this rare congenital anomaly, hairy elbows, was apparently that of Beighton (1970),1 who described it in two of five siblings. The hypertrichosis was noticed soon after birth, and reached its greatest extent and severity when the patients were 5 years old. Initially, the hairs were lanuginous, but later became long and coarser. After the patients reached the age of 5, the condition slowly regressed and the hairs again acquired a lanuginous appearance. The source of inheritance could not be determined.
No other cases have been reported since, but we have been advised through conversation with Darrell S. Wilkinson, MD (November 1977), about a few similar cases.
Report of a Case
A 5-year-old boy had mild hypertrichosis at birth that involved the extensor surfaces of both arms. A few weeks later, only a restricted area covering the elbows remained hairy. The hairs were long and silky,
Andreev VC, Stransky L. Hairy Elbows. Arch Dermatol. 1979;115(6):761. doi:10.1001/archderm.1979.04010060059036