title: Kinetics and effect of percutaneous administration of dihydrotestosterone in children.
abstract: BACKGROUND
  Percutaneous administration of dihydrotestosterone (DHT) has been successful in promoting phallic growth in infants and children with 5 alpha-reductase deficiency raised as males. We investigated whether percutaneous administration of DHT is similarly effective in patients with micropenis due to alternative diagnoses.
  
  
  METHODS
  Six patients (age range 1.9-8.3 years) with micropenis of variable etiology were studied prospectively. 2.5% DHT gel was applied to the phallus once daily at a dose of 0.15-0.33 mg/kg body weight. Serum DHT concentrations were measured at 0, 2, 4, 8, 12 and 24 h following application of DHT gel.
  
  
  RESULTS
  Peak DHT concentrations were attained within 2-8 h after application of the gel and subsequently remained within the normal adult range in all but 1 patient, who had received the lowest dose of 0.15 mg/kg. An increase in phallic growth, ranging from 0.5-2.0 cm, was achieved after 3-4 months of treatment in all patients whose DHT concentrations were maintained within adult range.
  
  
  CONCLUSIONS
  Percutaneous administration of DHT in a dose of 0.2-0.3 mg/kg once daily for a period of 3-4 months may be useful in the management of patients with testosterone biosynthetic defects, who have sufficient masculinization to warrant male sex assignment, or in patients with micropenis prior to reconstructive surgery.
authors.affiliation: London Centre for Paediatric Endocrinology, University College London, London, UK. charmane@mail.nih.gov
authors.forename: E
authors.initials: E
authors.lastname: Charmandari
authors.forename: M T
authors.initials: MT
authors.lastname: Dattani
authors.forename: L A
authors.initials: LA
authors.lastname: Perry
authors.forename: P C
authors.initials: PC
authors.lastname: Hindmarsh
authors.forename: C G
authors.initials: CG
authors.lastname: Brook
mesh_terms: D000287:Administration, Topical; D002648:Child; D002675:Child, Preschool; D013196:Dihydrotestosterone / Q000008:administration & dosage* / Q000097:blood / Q000493:pharmacokinetics / Q000627:therapeutic use; D004305:Dose-Response Relationship, Drug; D005782:Gels; D006801:Humans; D007223:Infant; D007700:Kinetics; D008297:Male; D009994:Osmolar Concentration; D010409:Penile Diseases / Q000188:drug therapy* / Q000503:physiopathology*; D010413:Penis / Q000187:drug effects* / Q000254:growth & development*; D011446:Prospective Studies; D013997:Time Factors
chemical_list: D005782:Gels; D013196:Dihydrotestosterone