Hirsutism is defined as excessive hair growth in various body areas commonly known as “androgen-dependent” sites. Androgens are a group of hormones present in both the male and female, but the levels are much higher in the male (ie. testosterone). Androgen dependent body sites refer to body areas where males have more hair, including the upper and lower back, lower abdomen, thighs and legs, between breasts, chin and the face. It is well known that there is a cultural bias regarding what is normal hair growth. In some parts of the world such as the Mediterranean, excessive hair can be observed in healthy women on the chin, sideburns and above the upper lip.
Severe form of hirsutism is called virilization. Virilization presents with deepening of the voice, male type balding, changes in body habitus and enlargement of the clitoris. Virilization is due to excessive amount of androgen production and generally related to tumors releasing androgenic hormones (adrenal hyperplasia, androgen producing tumors of the ovary and the adrenal gland).
Hair follicle is the invagination of the skin with cells at its base that produce keratin proteins which compose the thread of hair. Cells called melanocytes produce the pigment for the skin as well as the hair follicle. Approximately 4-5 million hair follicles are present in the body other than genitalia, palms and soles, and their regulation is significantly dependent on androgenic hormones in the body.
Androgenic hormones include dehydroepiandrosterone (DHEA), dehydroepiandrosterone sulfate (DHEAS) and testosterone (T). Testosterone is converted to dehydrotestosterone (DHT) in the hair follicle by the enzyme 5-alpha reductase. DHT is the most potent androgenic hormone involved in hair growth and distribution. Some women may have normal circulating T levels, but the activity and levels of DHT may be increased resulting in increased hair growth.
Clinical evaluation of hirsutism should be initiated by taking a detailed history and physical examination. Often times additional symptoms such as menstrual irregularities, infertility, milky discharge from the breasts (galactorrhea) and thyroid disease related signs can be identified. Certain drugs can result in excessive hair growth, especially some steroids that have androgenic activity. In some cases, it may be difficult to differentiate normal and excessive hair growth based on cultural