eMedicine Specialties > Pediatrics: General Medicine > Endocrinology

Microphallus: Treatment & Medication

Author: Karen S Vogt, MD, Pediatric Endocrinologist, Department of Pediatrics, Division of Endocrinology, Walter Reed Army Medical Center
Coauthor(s): Merrily P M Poth, MD, Professor, Department of Pediatrics and Neuroscience, Uniformed Services University of the Health Sciences; Andrew J Bauer, MD, Program Director, Department of Pediatrics, Division of Pediatric Endocrinology, Uniformed Services University of the Health Sciences; Michael J Bourgeois, MD, Director of Pediatric Undergraduate Medical Education, Associate Professor, Department of Pediatrics, Division of Pediatric Endocrinology and Metabolism, Texas Tech University School of Medicine
Contributor Information and Disclosures

Updated: Jul 9, 2008

Treatment

Medical Care

  • Testosterone therapy in the form of 3-6 monthly intramuscular (IM) injections has been used to increase penis size in infants and children.
  • Testosterone therapy has generally been found effective in treating micropenis due to testosterone deficiency.
    • In 1999, Bin-Abbas et al showed that 1 or 2 courses of 3 testosterone injections (25-50 mg) administered at 4-week intervals in infancy or childhood resulted in sufficient increase in penis sizes to reach the reference range for age.3
    • With appropriate pubertal and adult replacement, patients achieved normal adult penis size and reported sexual activity and appropriate gender identity.
  • Infants with other hormonal deficiencies (growth hormone deficiency, hypothyroidism, adrenal insufficiency) should receive appropriate hormonal replacements.

Surgical Care

  • Gender reassignment with appropriate genitoplasty has been performed. Because most boys with micropenis and descended testes are sensitive to testosterone therapy, consider genitoplasty only in extreme situations in which testosterone insensitivity is demonstrated. Even then, some authors question the wisdom of gender reassignment.
  • Circumcision should be avoided, or at least delayed, until appropriate evaluation, gender assignment, and therapy are completed. If associated with penile growth, testosterone therapy may facilitate the circumcision (see Medical Care).

Consultations

  • As soon as an infant is discovered to have micropenis, a pediatric endocrinologist should be consulted.
  • In some cases, the involvement of a pediatric urologist can also be helpful.
  • Psychological support and social services assistance may be useful.

Medication

Testosterone therapy has been shown to increase phallus size in infants with micropenis.

Androgenic hormones

Testosterone is the main androgenic hormone predominantly formed in the interstitial (Leydig) cells of the testes. In target tissues, it is converted to the more active form (DHT) by 5-alpha reductase. Testosterone controls the development and maintenance of the male sex organs and the male secondary sex characteristics. It also produces systemic anabolic effects to include increased erythropoietin, increased protein production, and increased retention of calcium. Testosterone is a schedule C-III controlled substance.


Testosterone cypionate or enanthate (Andro-LA, Delatest, Depo-Testosterone)

Promotes and maintains secondary sex characteristics in males with androgen deficiency.

Adult

Pediatric

Infants: 25 mg IM monthly for 3-6 doses
Children: 50 mg IM monthly for 3-6 doses
Adolescents with male hypogonadism:
Initiation of puberty: 40-50 mg/m2/dose IM every month
Terminal growth phase: 100 mg/m2/dose IM every month
Maintenance virilizing dose: 100 mg/m2/dose IM every 2 weeks

Potentiates effects of PO anticoagulants; increases propranolol clearance

Documented hypersensitivity; severe cardiac, hepatic, or renal disease; polycythemia; hypercalcemia; benign prostatic hypertrophy; males with carcinoma of the breast

Pregnancy

X - Contraindicated; benefit does not outweigh risk

Precautions

Adverse effects include early pubic hair growth and temporary acceleration of linear growth and bone age. Other adverse effects include water and sodium retention, potentiation of sleep apnea, and polycythemia. Use caution in patients with hepatic, cardiac, or renal dysfunction

More on Microphallus

Overview: Microphallus
Differential Diagnoses & Workup: Microphallus
Treatment & Medication: Microphallus
Follow-up: Microphallus
References
[ CLOSE WINDOW ]

References

  1. Tuladhar R, Davis PG, Batch J. Establishment of a normal range of penile length in preterm infants. J Paediatr Child Health. Oct 1998;34(5):471-3. [Medline].

  2. Robertson J, Shilkofski N. Mean Stretched Penile Length. The Harriet Lane Handbook. 2005;277.

  3. Bin-Abbas B, Conte FA, Grumbach MM. Congenital hypogonadotropic hypogonadism and micropenis: effect of testosterone treatment on adult penile size why sex reversal is not indicated. J Pediatr. May 1999;134(5):579-83. [Medline].

  4. Achermann JC, Hughes IA. Disorders of Sex Development. In: Kronenberg. Williams Textbook of Endocrinology. 11th ed. Philadelphia, PA: Saunders Elsevier; 2008:Chapter 22.

  5. Achermann JC, Ozisik G, Meeks JJ. Genetic causes of human reproductive disease. J Clin Endocrinol Metab. 2002;87:2447-2454. [Medline].

  6. Arrigo T, De Luca F, Maghnie M. Relationships between neuroradiological and clinical features in apparently idiopathic hypopituitarism. Eur J Endocrinol. Jul 1998;139(1):84-8. [Medline].

  7. Boehmer AL, Brinkmann AO, Sandkuijl LA, et al. 17Beta-hydroxysteroid dehydrogenase-3 deficiency: diagnosis, phenotypic variability, population genetics, and worldwide distribution of ancient and de novo mutations. J Clin Endocrinol Metab. Dec 1999;84(12):4713-21. [Medline].

  8. Bourgeois MJ, Jones B, Waagner DC. Micropenis and congenital adrenal hypoplasia. Am J Perinatol. Jan 1989;6(1):69-71. [Medline].

  9. Brinkmann A, Jenster G, Ris-Stalpers C. Molecular basis of androgen insensitivity. Steroids. Apr 1996;61(4):172-5. [Medline].

  10. Calikoglu AS. Should boys with micropenis be reared as girls? [editorial]. J Pediatr. May 1999;134(5):537-8. [Medline].

  11. Danon M, Friedman SC. Ambiguous genitalia, micropenis, hypospadias, and cryptorchidism. In: Pediatric Endocrinology. 3rd ed. Philadelphia, Pa:. WB Saunders;1996:297-301.

  12. Dissaneevate P, Warne GL, Zacharin MR. Clinical evaluation in isolated hypogonadotrophic hypogonadism (Kallmann syndrome). J Pediatr Endocrinol Metab. Sep-Oct 1998;11(5):631-8. [Medline].

  13. Drugs: Testosterone. MD Consult. Available at www.mdconsult.com. Accessed 15 May 2008.

  14. Feldman KW, Smith DW. Fetal phallic growth and penile standards for newborn male infants. J Pediatr. Mar 1975;86(3):395-8. [Medline].

  15. Gad YZ, Nasr H, Mazen I. 5 alpha-reductase deficiency in patients with micropenis. J Inherit Metab Dis. Mar 1997;20(1):95-101. [Medline].

  16. Grumbach MM. A window of opportunity: the diagnosis of gonadotropin deficiency in the male infant. J Clin Endocrinol Metab. May 2005;90(5):3122-7. [Medline].

  17. Hamilton J, Blaser S, Daneman D. MR imaging in idiopathic growth hormone deficiency. AJNR Am J Neuroradiol. Oct 1998;19(9):1609-15. [Medline].

  18. Hartke DM, Palmer JS. Anomalies of the penis. J Men's Health Gend. Sept 2006;3(3):244-249.

  19. Hayes FJ, Seminara SB, Crowley WF. Hypogonadotropic hypogonadism. Endocrinol Metab Clin North Am. 1998;27:739-763. [Medline].

  20. Lee YS, Kirk JM, Stanhope RG, et al. Phenotypic variability in 17beta-hydroxysteroid dehydrogenase-3 deficiency and diagnostic pitfalls. Clin Endocrinol (Oxf). Jul 2007;67(1):20-8. [Medline].

  21. Melmed S, Kleinberg D. Anterior Pituitary. In: Kronenberg. Williams Textbook of Endocrinology. 11th ed. Philadelphia, PA: Saunders Elsevier; 2008:Chapter 8.

  22. Palmer JS. Genitourinary manifestations in boys and girls associated with genetic disease. J Men's Health Gend. March 2006;3(1):71-79.

  23. Quigley CA. Editorial: The postnatal gonadotropin and sex steroid surge - Insights from the androgen insensitivity syndrome. J Clin Endocrinol Metab. 2002;87:24-28. [Medline].

  24. Ragan DC, Casale AJ, Rink RC. Genitourinary anomalies in the CHARGE association. J Urol. Feb 1999;161(2):622-5. [Medline].

  25. Schonfeld WA, Beebe GW. Normal growth and variation in male genitalia from birth to maturity. J Urol. 1942;64:759-777.

  26. Sinnecker GH, Hiort O, Dibbelt L. Phenotypic classification of male pseudohermaphroditism due to steroid 5 alpha-reductase 2 deficiency. Am J Med Genet. May 3 1996;63(1):223-30. [Medline].

  27. Styne DM, Grumbach MM. Puberty: Ontogeny, Neuroendocrinology, Physiology, and Disorders. In: Kronenberg. Williams Textbook of Endocrinology. 11th ed. Philadelphia, PA: Saunders Elsevier; 2008:Chapter 24.

  28. Toogood AA, Stewart PM. Hypopituitarism: clinical features, diagnosis, and management. Endocrinol Metab Clin North Am. Mar 2008;37(1):235-61, x. [Medline].

  29. Tsigos C, Latronico C, Chrousos GP. Luteinizing hormone resistance syndromes. Ann N Y Acad Sci. Jun 17 1997;816:263-73. [Medline].

  30. Wessells H, Lue TF, McAninch JW. Penile length in the flaccid and erect states: guidelines for penile augmentation. J Urol. Sep 1996;156(3):995-7. [Medline].

[ CLOSE WINDOW ]

Further Reading

[ CLOSE WINDOW ]

Keywords

microphallus, micropenis, ambiguous genitalia, hypospadia, small genitalia, growth hormone deficiency, small penis, tiny penis, absent penis, 5-alpha reductase deficiency, partial androgen insensitivity syndrome, Prader-Willi syndrome, Klinefelter syndrome, Noonan syndrome, hypopituitarism, hypoadrenalism, electrolyte abnormalities, hypotension, shock, gender identity, cryptorchidism, gender reassignment, clitoromegaly, neonatal hypoglycemia, Kallman syndrome, adrenal insufficiency, cleft lip, cleft palate, midfacial hypoplasia, hypogonadotropic hypogonadism, congenital heart disease, renal agenesis, sensorineural deafness, visual abnormalities, synkinesia, septum pellucidum, optic nerve hypoplasia, septo-optic dysplasia, SOD, testicular degeneration, tall stature, gynecomastia, small firm testes, increased leg length, short stature, end-stage renal disease, hepatic fibrosis, hearing loss, Bardet-Biedl syndrome, CHARGE syndrome, Robinow syndrome, Rud syndrome

[ CLOSE WINDOW ]

Contributor Information and Disclosures

Author

Karen S Vogt, MD, Pediatric Endocrinologist, Department of Pediatrics, Division of Endocrinology, Walter Reed Army Medical Center
Karen S Vogt, MD is a member of the following medical societies: American Academy of Pediatrics, American Diabetes Association, Endocrine Society, and Lawson-Wilkins Pediatric Endocrine Society
Disclosure: Nothing to disclose.

Coauthor(s)

Merrily P M Poth, MD, Professor, Department of Pediatrics and Neuroscience, Uniformed Services University of the Health Sciences
Merrily P M Poth, MD is a member of the following medical societies: American Academy of Pediatrics, Endocrine Society, and Lawson-Wilkins Pediatric Endocrine Society
Disclosure: Nothing to disclose.

Andrew J Bauer, MD, Program Director, Department of Pediatrics, Division of Pediatric Endocrinology, Uniformed Services University of the Health Sciences
Andrew J Bauer, MD is a member of the following medical societies: American Academy of Pediatrics, American Thyroid Association, Endocrine Society, and Lawson-Wilkins Pediatric Endocrine Society
Disclosure: Nothing to disclose.

Michael J Bourgeois, MD, Director of Pediatric Undergraduate Medical Education, Associate Professor, Department of Pediatrics, Division of Pediatric Endocrinology and Metabolism, Texas Tech University School of Medicine
Michael J Bourgeois, MD is a member of the following medical societies: American Academy of Pediatrics, American Diabetes Association, and Texas Medical Association
Disclosure: Nothing to disclose.

Medical Editor

Arlan L Rosenbloom, MD, Adjunct Distinguished Service Professor Emeritus of Pediatrics, University of Florida; Fellow of the American Academy of Pediatrics; Fellow of the American College of Epidemiology
Arlan L Rosenbloom, MD is a member of the following medical societies: American Academy of Pediatrics, American College of Epidemiology, American Pediatric Society, Endocrine Society, Florida Pediatric Society, Lawson-Wilkins Pediatric Endocrine Society, and Society for Pediatric Research
Disclosure: Nothing to disclose.

Pharmacy Editor

Mary L Windle, PharmD, Adjunct Assistant Professor, University of Nebraska Medical Center College of Pharmacy, Pharmacy Editor, eMedicine.com, Inc
Disclosure: Pfizer Inc Stock Investment from broker recommendation; Avanir Pharma Stock Investment from broker recommendation

Managing Editor

George P Chrousos, MD, FAAP, MACP, MACE, Professor and Chair, Department of Pediatrics, Athens University Medical School
George P Chrousos, MD, FAAP, MACP, MACE is a member of the following medical societies: American Academy of Pediatrics, American College of Endocrinology, American College of Physicians, American Pediatric Society, American Society for Clinical Investigation, Association of American Physicians, Endocrine Society, Lawson-Wilkins Pediatric Endocrine Society, and Society for Pediatric Research
Disclosure: Nothing to disclose.

CME Editor

Merrily P M Poth, MD, Professor, Department of Pediatrics and Neuroscience, Uniformed Services University of the Health Sciences
Merrily P M Poth, MD is a member of the following medical societies: American Academy of Pediatrics, Endocrine Society, and Lawson-Wilkins Pediatric Endocrine Society
Disclosure: Nothing to disclose.

Chief Editor

Stephen Kemp, MD, PhD, Professor, Department of Pediatrics, Section of Pediatric Endocrinology, University of Arkansas and Arkansas Children's Hospital
Stephen Kemp, MD, PhD is a member of the following medical societies: American Academy of Pediatrics, American Association of Clinical Endocrinologists, American Pediatric Society, Endocrine Society, Phi Beta Kappa, Southern Medical Association, and Southern Society for Pediatric Research
Disclosure: Genentech, Inc. Honoraria Speaking and teaching; Pfiser, Inc. Honoraria Consulting

RELATED MEDSCAPE ARTICLES
Articles
 
 
HONcode

We subscribe to the
HONcode principles of the
Health On the Net Foundation

All material on this website is protected by copyright, Copyright© 1994- by Medscape.
This website also contains material copyrighted by 3rd parties.

DISCLAIMER: The content of this Website is not influenced by sponsors. The site is designed primarily for use by qualified physicians and other medical professionals. The information contained herein should NOT be used as a substitute for the advice of an appropriately qualified and licensed physician or other health care provider. The information provided here is for educational and informational purposes only. In no way should it be considered as offering medical advice. Please check with a physician if you suspect you are ill.