Topical dihydrotestosterone to treat micropenis secondary to partial androgen insensitivity syndrome (PAIS) before, during, and after puberty - a case series.
BACKGROUND
X-linked partial androgen insensitivity syndrome (PAIS) causes under-virilization at all stages of development. In two thirds of males, this results in micropenis. Dihydrotestosterone (DHT) is a potent androgen that is critical for male genital development, which when applied topically, has been shown to increase penile length with micropenis of varying etiologies. We present the first case series using topical DHT gel to treat micropenis in 46,XY males with PAIS, before, during, and after puberty.


METHODS
Three related 46,XY males with confirmed p.L712F androgen receptor mutations exhibited varying degrees of micropenis post-surgical correction. They were of pre-pubertal, peri-pubertal and adult ages, respectively. Following baseline clinical and laboratory assessments all completed a 4-month course of daily DHT gel 2.5% (androstanolone) topically to penis (0.3 mg/kg body weight), with monitoring for adverse effects. Primary outcome was change in stretched penile length (SPL) following treatment.


RESULTS
Mixed results were obtained following topical DHT therapy. In the pre- and peri- pubertal patients, SPL changed from 2.5 cm to 3.5 cm (+40%), and 3.5 cm to 5.7 cm (+63%), respectively. In the adult patient with 1 year of prior high-dose weekly testosterone therapy, no additional change in SPL was seen. No adverse effects of topical DHT were reported or observed throughout the 4 months of treatment.


CONCLUSIONS
Topical DHT treatment appears to be a safe and well-tolerated method of virilising micropenis both prior to and during puberty in children with PAIS. Questions remain about long-term outcomes into adulthood, and efficacy in adults with prior lengthy exposure to high-dose testosterone.
David
D
Becker
Lisa M
LM
Wain
Yih Harng
YH
Chong
Sonal J
SJ
Gosai
Nina K
NK
Henderson
Jacqui
J
Milburn
Victoria
V
Stott
Benjamin J
BJ
Wheeler
D000287:Administration, Topical; D000293:Adolescent; D000328:Adult; D013734:Androgen-Insensitivity Syndrome / Q000188:drug therapy*; D002648:Child; D013196:Dihydrotestosterone / Q000008:administration & dosage*; D005832:Genital Diseases, Male / Q000188:drug therapy*; D006801:Humans; D008297:Male; D010375:Pedigree; D010413:Penis / Q000002:abnormalities*; D011627:Puberty; D055815:Young Adult
D013196:Dihydrotestosterone