Effect of insulin-like growth factor-1 deficiency or administration on the occurrence of acne.

Background  The role of growth hormone, insulin, and insulin-like growth factor-1 (IGF-1) in the development of acne is incompletely understood. Objective  To study the effect of the absence of IGF-1 and its pharmacologic replacement on the occurrence of acne vulgaris. Patients and Methods  Laron syndrome (LS) is characterized by congenital IGF-1 deficiency. The study group consisted of 21 patients with classical LS, who underwent puberty: 13 (8 male, 5 female) untreated and under regular follow-up until age 20?48 years; and 8 (2 male, 6 female) treated with IGF-1 (70–200 μg/kg/day), including 6 adults (2 male, treated at age 14.5–29 years and 4 female, treated at age 30–37 years) and 2 adolescents (2 female, treated at age 3.5–16 years). The medical files were reviewed for occurrence of acne and the corresponding sex hormone levels, and the findings were compared between the treated and untreated patients. Results  Puberty was delayed in all untreated patients. Only one patient had slight acne at age 22 years, when he reached full puberty. Among the 2 IGF-1 treated male patients, none acquired acne. Among the 6 treated female patients, 3 had signs of hyperandrogenism (oligo-amenorrhea) and acne during IGF-1 over-dosage. On reduction of the IGF-1 dose (to 50 μg/kg/day) or cessation of treatment, the acne disappeared in all 3 patients. Conclusion  This study demonstrates for the first time that serum IGF-1 deficiency prevents the occurrence of acne. The findings suggest that an interaction between IGF-1 and androgens is necessary for the development of acne.