Localized acquired hypertrichosis after cast treatment in pediatric and adolescent patients: a natural history study

Localized acquired hypertrichosis (LAH) is a condition characterized by increased hair growth and is frequently seen after cast removal in children and adolescents. The purpose of this study was to examine the natural history of LAH and its potential impact on patients' quality of life.

Patients between the ages of 5 and 16 years, in whom hypertrichosis was detected after the removal of a cast were enrolled in a prospective study. Each patient completed the Children's Dermatology Life Quality Index after cast removal and at follow-up. Each patient was followed up until complete resolution of hypertrichosis. Statistical analyses were performed to determine any relation between the time to resolution of hypertrichosis and potential contributing variables including age, sex, initial diagnosis, type of cast, type of cast liner, and duration of cast.

Of the 25 enrolled patients, 3 were lost during follow-up and 1 girl was excluded. The mean Children's Dermatology Life Quality Index total score was 1.1±1.4, with the majority of patients (68%) scoring 0 or 1. The hypertrichosis was completely resolved within 6 months in 17 of the 21 patients and within 6 to 12 months in the remaining 4. Although duration of cast showed a statistically significant correlation to time to resolution (P=0.008), the other variables studied showed no significant relationship.

According to this study, LAH is typically resolved within 6 months in 80% of patients. It was not found to negatively impact the quality of life in any of the patients. The study determined that the longer the cast was applied, the longer was the time for hypertrichosis to resolve.

Level II, prognostic study.