Unwanted hair growth in women is a problem called hirsutism. It caused by hair follicles that react to increased level of androgen hormones. If facial hair growth in women is not caused by androgen, then this condition is called hypertrichosis.
Women with hirsutism develop unwanted or excessive hair growth in places that normally occur in men. For instance they develop hair growth on the face, upper lip, chin, chest and legs. Hirsutism in itself is not a disease if it occurs in women when they have a normal menstrual cycle.
Women and men have the same number of hair follicles on the body. The only places that lack hair follicles are the soles of the hand, feet and lips. There are three types of hair follicles
- Lanugo hair; this is thin baby hair found on newborns and is shed within a few weeks to be replaced by vellus hair
- Vellus hair; this is short hair without pigment and cover most of the skin
- Terminal hair; this is long, thick pigment hair found on the head, eyebrows, armpits and pubic region.
Vellus hair can grow into terminal hair under the influence of androgen hormone. There are three stages of hair growth in men and women
- Anagen – the phase that determines the length of the hair, the longer the hair stays in this phase, the longer the hair will be
- Catagen – the phase in which the hair follicle renews itself and nothing happens – this lasts about 2 weeks
- Telogen – the phase in which the hair sheds from the skin
The skin is full of receptors and enzymes. Testosteron can be converted into androgen hormone in the skin by an enzyme called 5-alpha reductase. The androgen attaches to receptors on the vellus hair follicle to stimulate them and they then grow into terminal hairs. Women with an abnormal interaction between androgen formed in the skin and the hair receptors will develop hirsutism.
If women with hirsutism have normal menstrual cycles then this condition is not pathological and no further tests are needed. A GP could advice hair removal via laser-treatment at a skin therapy clinic. If women have hirsutism and an irregular menstrual cycle, then a GP should proceed with further tests such as determine the level of androgen hormones. A high level of androgen hormone can be caused by disease of the adrenal glands or in women with polycystic ovarium syndrome (PCOS).
The GP will want to know about the following conditions in order to determine whether it is hirsutism
- location of unwanted hair growth
- how the condition has progressed
- if this occurs in other female family members
- changes in menstruation
- use of contraception
- desires to have child(ren)
- weight loss or weight gain
- use of medication in particular anabolic steroids or danazol (used to treat endometriosis or fibrous cystics breast disease)
- use of anti-hair treatment
- the psychological consequences of excessive hair growth
- worries with regards to fertility
Next the GP will perform a physical examination and will look for presence of terminal hair growth on the breast, abdomen, back, upper legs, upper arms and face. A score from 0 (no terminal hair growth) to 4 (excessive terminal hair growth) is given based on the findings. A score of more than 8 in a light-skinned woman is classified as hirsutism.
The GP will then look at signs of
- obesity or excess fat tissue on the body
- masculine voice
- male-pattern boldness
- small breasts
- increased muscle
- enlarged clitoris
- large thyroid gland
- signs of systemic illness
A referral to a gynaecologist or endocrinologist is made when there are signs of hormonal imbalance and or changes in menstrual cycle.
There are no medication available for women who have hirsutism and normal menstrual cycle. In case of changes in menstruation and no wishes to bear children, women can opt to take an oral contraception pill. The effect is that oestrogen will stimulate testosteron binding SHBG that in turns inactivates testosteron. This in turns means that 5-alpha reductase is not able to convert the inactivated testosterone into androgen. Without androgen, vellus hair is not able to grow as terminal hair and hence reduces the presence of unwanted hair growth.
Obese women with hirsutism are encouraged to loose weight since testosteron is converted to oestradiol in fatty tissue. Oestradiol decreased follicle stimulating hormones (FSH) such that ovaries are not able to release an egg for ovulation. This causes changes in menstrual cycles.
Hirsutism is a response to hormone androgen receptors on thin hair follicles that cause them to grow into thick long hair. The presence of unwanted hair growth in the face, breast, back, upper limbs and lip can be scored 0-24 points. A score of 8 or more signals the presence of hirsutism. A GP will need to know if this occurs with a normal or abnormal menstrual cycle before he or she decides on referral to specialist care.