Hirsutism is the excessive growth of thick or dark hair in women in locations that are more typical of male hair growth patterns (eg, mustache, beard, central chest, shoulders, lower abdomen, back, inner thigh). The amount of hair growth that is considered excessive may differ depending on ethnic background and cultural interpretation.
Hypertrichosis is a separate condition. It is simply an increase in the amount of hair growth anywhere on the body. Hypertrichosis may be generalized or localized.
Men vary significantly in amount of body hair, some being quite hairy, but rarely present for medical evaluation.
Pathophysiology of Hirsutism and Hypertrichosis
Hair growth depends on the balance between androgens (eg, testosterone, dehydroepiandrosterone sulfate [DHEAS], dihydrotestosterone [DHT]) and estrogens. Androgens promote thick, dark hair growth. Testosterone stimulates hair growth in the pubic area and underarms. Dihydrotestosterone stimulates beard hair growth and scalp hair loss.
Hirsutism can be due to an
Hirsutism typically results from abnormally high androgen levels as a result of increased production of androgens (eg, due to ovarian or adrenal disorders) or increased peripheral conversion of testosterone to DHT by 5-alpha-reductase. Free androgen levels also can increase as a result of decreased production of sex hormone–binding globulin, which can occur in a variety of conditions, including hyperinsulinemia, hyperprolactinemia, and in androgen excess itself. However, the severity of hirsutism does not correlate with the level of circulating androgens because of individual differences in androgen sensitivity of the hair follicle.
Hirsutism also may be the result of increased end organ response to normal plasma levels of androgens and manifest as a familial phenomenon in people of Mediterranean, South Asian, or Middle Eastern ancestry. Hirsutism in pregnancy and menopause is due to temporary, physiologic fluctuations in androgen levels.
When caused by increased androgen levels, hirsutism is often accompanied by virilization, which may manifest as loss of menses, increased muscle mass, voice deepening, acne, androgenetic alopecia Etiology Alopecia is defined as loss of hair from the body. Hair loss is often a cause of great concern to the patient for cosmetic and psychologic reasons, but it can also be an important sign of systemic... read more 
, and clitoromegaly.
Hypertrichosis involves nonandrogenic hair growth.
Etiology of Hirsutism and Hypertrichosis
There are a number of causes of hirsutism (see table Some Causes of Hirsutism Some Causes of Hirsutism Hirsutism is the excessive growth of thick or dark hair in women in locations that are more typical of male hair growth patterns (eg, mustache, beard, central chest, shoulders, lower abdomen... read more 
).
Overall, the most common cause is
Hypertrichosis is usually caused by a drug, systemic illness (see table Causes of Hypertrichosis Causes of Hypertrichosis Hirsutism is the excessive growth of thick or dark hair in women in locations that are more typical of male hair growth patterns (eg, mustache, beard, central chest, shoulders, lower abdomen... read more ), or paraneoplastic syndrome Paraneoplastic Syndromes Paraneoplastic syndromes are symptoms that occur at sites distant from a tumor or its metastasis. Although the pathogenesis remains unclear, these symptoms may be secondary to substances secreted... read more 
. It also occurs in rare familial disorders called congenital hypertrichosis.
Evaluation of Hirsutism and Hypertrichosis
History
History of present illness should cover the extent, location, and acuity of hair growth as well as the age of onset.
Review of systems should seek symptoms of virilization and review menstrual and fertility history. Symptoms of causative disorders should be sought, including polyuria (diabetes), bingeing and purging (eating disorders), and weight loss and fevers (cancer).
Past medical history should specifically seek known causative disorders such as endocrine disorders, adrenal or ovarian pathology, and cancer.
Family history should inquire about excess hair growth in family members.
Drug history should review all prescribed drugs and specifically query for the surreptitious use of anabolic steroids Anabolic Steroids Anabolic steroids are often used to enhance physical performance and promote muscle growth. When used inappropriately, chronically at high doses and without medical supervision, they can cause... read more .
Physical examination
The presence of excess coarse and dark hair growth should be assessed at multiple sites, including the face, chest, lower abdomen, back, buttocks, and inner thigh. Signs of virilization should be sought, including
General physical examination should note signs of potentially causative disorders:
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The general habitus should be examined for fat distribution (particularly a round face and accumulation of fat at the base of the neck posteriorly).
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The skin should be examined for velvety, black pigmentation on the axillae and neck and under the breasts (acanthosis nigricans), and striae.
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The eyes should be examined for extraocular movements and the visual fields should be assessed.
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The breasts should be examined for galactorrhea.
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The abdomen (including pelvic examination) should be examined for masses.
Red flags
Interpretation of findings
Excess hair growth beginning after use of an anabolic steroid or other causative drug (see table Causes of Hypertrichosis Causes of Hypertrichosis Hirsutism is the excessive growth of thick or dark hair in women in locations that are more typical of male hair growth patterns (eg, mustache, beard, central chest, shoulders, lower abdomen... read more ) in an otherwise healthy female is likely due to that drug. Symptoms and signs sometimes point to an underlying diagnosis (see table Interpreting Findings in Hirsutism Interpreting Findings in Hirsutism Hirsutism is the excessive growth of thick or dark hair in women in locations that are more typical of male hair growth patterns (eg, mustache, beard, central chest, shoulders, lower abdomen... read more ).
Abrupt-onset of hirsutism or hypertrichosis may portend cancer. The abrupt onset of hirsutism may be due to adrenal, ovarian, or pituitary tumors or from ectopic hormone production from other types of tumors. Hypertrichosis lanuginosa (malignant down) is fine hair growth that appears over the entire body over a short period of time, although it can be localized to the face in mild forms.
Testing
Diagnostic testing in men with no other signs of illness is unnecessary.
Women should have laboratory measurement of serum hormone levels, including the following:
Depending on clinical findings, androstenedione and/or prolactin levels may also be measured.
High levels of testosterone accompanied by a normal level of DHEAS indicate that the ovaries, and not the adrenal glands, are producing the excess androgen. High levels of testosterone accompanied by moderate elevations in DHEAS suggest an adrenal origin for the hirsutism.
Often, in women with polycystic ovary syndrome, LH levels are elevated and FSH levels are depressed, which results in elevated LH/FSH ratios (> 3 is common for polycystic ovary syndrome Polycystic Ovary Syndrome (PCOS) Polycystic ovary syndrome is a clinical syndrome characterized by mild obesity, irregular menses or amenorrhea, and signs of androgen excess (eg, hirsutism, acne). Most patients have multiple... read more 
).
Imaging
Pelvic ultrasonography and/or CT or MRI should be done to rule out pelvic or adrenal cancer, particularly when a pelvic mass is suspected, when the total testosterone level is > 150 ng/dL (5.2 nmol/L) or > 100 ng/dL (3.5 nmol/L) in postmenopausal women, or when the DHEAS level is > 700 mcg/dL (19 micromol/L) or > 400 mcg/dL (10.8 micromol/L) in postmenopausal women. However, the majority of patients with elevated DHEAS have adrenal hyperplasia rather than adrenal carcinoma.
Patients with signs of Cushing syndrome or an adrenal mass on imaging studies should have 24-hour measurement of urine cortisol levels.
Treatment of Hirsutism and Hypertrichosis
The underlying disorder should be treated, including stopping or changing causative drugs.
Treatment for hirsutism itself is necessary only if the patient finds the excess hair cosmetically objectionable. Patients with androgen-dependent hirsutism require a combination of hair removal and antiandrogen therapy.
Nonandrogen–dependent excess hair growth, such as hypertrichosis, is treated primarily with physical hair removal methods.
Topical treatments
There are several techniques.
Depilatory techniques remove hair from the surface of the skin and include shaving and over-the-counter depilatory creams, such as those containing barium sulfate and calcium thioglycolate.
Epilation involves removing intact hairs with their roots and can be achieved via mechanical means (eg, tweezing, plucking, waxing) or home epilating devices. Permanent epilation techniques, including electrolysis, thermolysis, and laser epilation, can result in more long-term hair removal but often require multiple treatments.
As an alternative to hair removal, hair bleaching is inexpensive and works well when hirsutism is not excessive. Bleaches lighten the color of the hair, rendering it less noticeable. There are several types of commercial hair-bleaching products, most of which use hydrogen peroxide as the active ingredient.
Topical eflornithine, applied twice daily, slows the rate of hair growth and, with long-term use, may increase the amount of time between hair removal treatments.
Hormonal treatment
Hirsutism resulting from androgen excess usually requires long-term therapy because the source of excess androgen rarely can be eliminated permanently. Hormonal treatments include
Oral contraceptives in standard doses often are the initial treatment for hirsutism caused by ovarian hyperandrogenism. Oral contraceptives reduce ovarian androgen secretion and increase sex hormone–binding globulin, thereby decreasing free testosterone levels.
Antiandrogenic therapy is also used and can include finasteride (1 to 5 mg orally once/day) or spironolactone (25 to 100 mg orally 2 times a day). These drugs are contraindicated in women of childbearing age unless contraception is used because they may feminize a male fetus.
Corticosteroids are used when necessary to suppress adrenal androgen production. Gonadotropin-releasing hormone agonists (eg, leuprolide acetate, nafarelin, triptorelin) can be used for severe forms of ovarian hyperandrogenism under the direction of a gynecologist or endocrinologist.
