Intradermal Growing Hair: Two Case Reports.

Hair growing inside the skin and burrowing in the uppermost dermis, previously termed as "ingrowing hair," is a rarely reported cutaneous disorder. Up to July 31, 2018, only five cases have been reported, all were male. The authors report two Chinese Han men, 26-year-old and 31-year-old respectively, presenting with progressive extending black lines inside the skin on the right mandibular angle and the neck respectively. The black lines were finally demonstrated as growing beard hairs. The 26-year-old man was cured after the hair was pulled out, whereas the 31-year-old patient had re-occurrence after the initial hair was extracted and was cured finally by destroying the individual beard follicle. The authors would prefer the term of "intradermal growing hair" to "ingrowing hair" when describing the condition of hair growing inside the skin and extending in the uppermost dermis. Pulling out the growing hair, and sometimes destroying the beard follicle, may be of choice for its treatment.