Pathophysiology and causes of hirsutism
- Robert L Barbieri, MD
Robert L Barbieri, MD
- Editor-in-Chief — Obstetrics, Gynecology and Women's Health
- Section Editor — General Gynecology and Female Reproductive Endocrinology
- Kate Macy Ladd Professor of Obstetrics, Gynecology and Reproductive Biology
- Harvard Medical School
- David A Ehrmann, MD
David A Ehrmann, MD
- Professor of Medicine
- University of Chicago
- Section Editors
- Peter J Snyder, MD
Peter J Snyder, MD
- Editor-in-Chief — Endocrinology
- Section Editor — Pituitary Disease; Male Reproductive Endocrinology
- Professor of Medicine
- University of Pennsylvania School of Medicine
- William F Crowley, Jr, MD
William F Crowley, Jr, MD
- Section Editor — Female Reproductive Endocrinology
- Daniel K Podolsky Professor of Medicine
- Harvard Medical School
Hirsutism, defined as excessive male-pattern hair growth, affects between 5 and 10 percent of women of reproductive age. Hirsutism may be the initial and possibly only sign of androgen excess, the cutaneous manifestations of which may also include acne and male-pattern balding (androgenetic alopecia). The pathophysiology and causes of androgen-mediated hair growth are reviewed here. Evaluation and treatment of hirsutism are discussed separately. (See "Evaluation of premenopausal women with hirsutism" and "Treatment of hirsutism".)
Hair growth cycle — Humans are born with approximately five million hair follicles, and it is estimated that 80,000 to 150,000 of them are located on the scalp. Hair can be categorized as either vellus (fine, soft, and not pigmented) or terminal (long, coarse, and pigmented) . The number of hair follicles does not change over an individual's lifetime, but the follicle size and type of hair can change in response to numerous factors, particularly androgens.
The hair growth cycle is comprised of three phases :
●The growth phase (termed anagen), which varies by body area, is about four months for facial hair. Therefore, it takes about six months to detect the effects of hormonal therapy for facial hirsutism.
●The involutional phase (catagen), which lasts two to three weeks.
- Deplewski D, Rosenfield RL. Role of hormones in pilosebaceous unit development. Endocr Rev 2000; 21:363.
- Paus R, Cotsarelis G. The biology of hair follicles. N Engl J Med 1999; 341:491.
- Messenger AG. The control of hair growth: an overview. J Invest Dermatol 1993; 101:4S.
- Azziz R, Carmina E, Sawaya ME. Idiopathic hirsutism. Endocr Rev 2000; 21:347.
- Reingold SB, Rosenfield RL. The relationship of mild hirsutism or acne in women to androgens. Arch Dermatol 1987; 123:209.
- Karrer-Voegeli S, Rey F, Reymond MJ, et al. Androgen dependence of hirsutism, acne, and alopecia in women: retrospective analysis of 228 patients investigated for hyperandrogenism. Medicine (Baltimore) 2009; 88:32.
- McManus SS, Levitsky LL, Misra M. Polycystic ovary syndrome: clinical presentation in normal-weight compared with overweight adolescents. Endocr Pract 2013; 19:471.
- Hatch R, Rosenfield RL, Kim MH, Tredway D. Hirsutism: implications, etiology, and management. Am J Obstet Gynecol 1981; 140:815.
- Samojlik E, Kirschner MA, Silber D, et al. Elevated production and metabolic clearance rates of androgens in morbidly obese women. J Clin Endocrinol Metab 1984; 59:949.
- Kirschner MA, Samojlik E, Silber D. A comparison of androgen production and clearance in hirsute and obese women. J Steroid Biochem 1983; 19:607.
- Matteri RK, Stanczyk FZ, Gentzschein EE, et al. Androgen sulfate and glucuronide conjugates in nonhirsute and hirsute women with polycystic ovarian syndrome. Am J Obstet Gynecol 1989; 161:1704.
- Labrie F. Intracrinology. Mol Cell Endocrinol 1991; 78:C113.
- FERRIMAN D, GALLWEY JD. Clinical assessment of body hair growth in women. J Clin Endocrinol Metab 1961; 21:1440.
- Knochenhauer ES, Key TJ, Kahsar-Miller M, et al. Prevalence of the polycystic ovary syndrome in unselected black and white women of the southeastern United States: a prospective study. J Clin Endocrinol Metab 1998; 83:3078.
- Azziz R, Sanchez LA, Knochenhauer ES, et al. Androgen excess in women: experience with over 1000 consecutive patients. J Clin Endocrinol Metab 2004; 89:453.
- Carmina E, Rosato F, Jannì A, et al. Extensive clinical experience: relative prevalence of different androgen excess disorders in 950 women referred because of clinical hyperandrogenism. J Clin Endocrinol Metab 2006; 91:2.
- Souter I, Sanchez LA, Perez M, et al. The prevalence of androgen excess among patients with minimal unwanted hair growth. Am J Obstet Gynecol 2004; 191:1914.
- DeUgarte CM, Woods KS, Bartolucci AA, Azziz R. Degree of facial and body terminal hair growth in unselected black and white women: toward a populational definition of hirsutism. J Clin Endocrinol Metab 2006; 91:1345.
- Carmina E, Koyama T, Chang L, et al. Does ethnicity influence the prevalence of adrenal hyperandrogenism and insulin resistance in polycystic ovary syndrome? Am J Obstet Gynecol 1992; 167:1807.
- Welt CK, Arason G, Gudmundsson JA, et al. Defining constant versus variable phenotypic features of women with polycystic ovary syndrome using different ethnic groups and populations. J Clin Endocrinol Metab 2006; 91:4361.
- O'Driscoll JB, Mamtora H, Higginson J, et al. A prospective study of the prevalence of clear-cut endocrine disorders and polycystic ovaries in 350 patients presenting with hirsutism or androgenic alopecia. Clin Endocrinol (Oxf) 1994; 41:231.
- Moore A, Magee F, Cunningham S, et al. Adrenal abnormalities in idiopathic hirsutism. Clin Endocrinol (Oxf) 1983; 18:391.
- Glickman SP, Rosenfield RL. Androgen metabolism by isolated hairs from women with idiopathic hirsutism is usually normal. J Invest Dermatol 1984; 82:62.
- Escobar-Morreale HF, Serrano-Gotarredona J, García-Robles R, et al. Mild adrenal and ovarian steroidogenic abnormalities in hirsute women without hyperandrogenemia: does idiopathic hirsutism exist? Metabolism 1997; 46:902.
- Adams J, Polson DW, Franks S. Prevalence of polycystic ovaries in women with anovulation and idiopathic hirsutism. Br Med J (Clin Res Ed) 1986; 293:355.
- Chetkowski RJ, DeFazio J, Shamonki I, et al. The incidence of late-onset congenital adrenal hyperplasia due to 21-hydroxylase deficiency among hirsute women. J Clin Endocrinol Metab 1984; 58:595.
- Kuttenn F, Couillin P, Girard F, et al. Late-onset adrenal hyperplasia in hirsutism. N Engl J Med 1985; 313:224.
- Hawkins LA, Chasalow FI, Blethen SL. The role of adrenocorticotropin testing in evaluating girls with premature adrenarche and hirsutism/oligomenorrhea. J Clin Endocrinol Metab 1992; 74:248.
- Dewailly D, Vantyghem MC, Lemaire C, et al. Screening heterozygotes for 21-hydroxylase deficiency among hirsute women: lack of utility of the adrenocorticotropin hormone test. Fertil Steril 1988; 50:228.
- Moltz L, Pickartz H, Sörensen R, et al. Ovarian and adrenal vein steroids in seven patients with androgen-secreting ovarian neoplasms: selective catheterization findings. Fertil Steril 1984; 42:585.
- Friedman CI, Schmidt GE, Kim MH, Powell J. Serum testosterone concentrations in the evaluation of androgen-producing tumors. Am J Obstet Gynecol 1985; 153:44.
- Meldrum DR, Abraham GE. Peripheral and ovarian venous concentrations of various steroid hormones in virilizing ovarian tumors. Obstet Gynecol 1979; 53:36.
- Derksen J, Nagesser SK, Meinders AE, et al. Identification of virilizing adrenal tumors in hirsute women. N Engl J Med 1994; 331:968.
- Hair growth cycle
- Role of androgens
- Generalized hair growth
- Polycystic ovary syndrome
- Idiopathic hirsutism
- Nonclassic congenital adrenal hyperplasia
- Women with virilization or severe hyperandrogenemia
- - Androgen-secreting tumors
- - Ovarian hyperthecosis
- INFORMATION FOR PATIENTS