Alopecia is the medical term that describes a loss of hair and sometimes baldness.

Sometimes, hair loss is a side effect of the cancer treatment medicines that are used in chemotherapy. In these cases, hair loss is usually temporary. However, any type of hair loss can reduce confidence and self-esteem.

Types of hair loss

The main types of hair loss are summarised below.

Male-pattern baldness

Male-pattern baldness is the commonest type of hair loss. As well as affecting men, it can sometimes affect women (female-pattern baldness). It can be particularly difficult for both men and women to cope with.

Male- and female-pattern baldness follows a pattern of a receding hairline, followed by thinning of the hair on the crown and temples.

Male- and female-pattern baldness is also called androgenic alopecia. ‘Androgenic’ means linked to male hormones. This type of hair loss is linked to the hormone dihydrotestosterone (DHT), which is made from the male hormone testosterone. See Hair loss – causes for more information.

Alopecia areata

Alopecia areata is another type of hair loss, involving patches of baldness that may come and go. It can occur at any age, but mostly affects teenagers and young adults. Six of 10 people who are affected develop their first bald patch before they are 20 years old.

Alopecia areata is thought to be caused by a problem with the immune system (the body’s natural defence against infection and illness). There is no proven effective treatment. In most cases the hair grows back after about a year.

Some people with alopecia areata go on to develop a more severe form of hair loss, such as:

• alopecia totalis (no scalp hair)
• alopecia universalis (no hair on the scalp and body)

Scarring alopecia

Scarring alopecia is hair loss that occurs as a result of complications from another condition. In this type of alopecia, the hair follicle (the small hole in your skin that an individual hair grows out of) is completely destroyed. This means that your hair will not grow back.

Conditions that can cause scarring alopecia include:

• scleroderma – a condition that affects the body’s connective (supporting) tissues, resulting in hard, puffy and itchy skin
• lichen planus – a non-infectious, itchy rash that can affect many areas of the body
• shingles – an infection of a nerve and the area of skin around it, caused by the herpes varicella-zoster virus, which is also responsible for causing chickenpox

Rarer conditions that can cause scarring alopecia include:

• folliculitis decalvans – a rare form of alopecia that most commonly affects men; it causes baldness and scarring of the affected areas
• frontal fibrosing alopecia – a type of alopecia that affects post-menopausal women; it damages the hair follicles so that the hair falls out and is unable to grow back
• discoid lupus- a mild form of  lupus that affects the skin, causing scaly marks and hair loss

Telogen effluvium

Telogen effluvium is a common type of alopecia where there is widespread thinning of the hair, rather than specific bald patches. Hair is shed from the scalp, usually as a reaction to stress or medication. This type of hair loss tends to improve without treatment after a few months.

Other causes of hair loss

Traction alopecia is caused by forceful brushing, tight braiding or often by  habitual twisting of the scalp hair. Ceasing the cause should result in recovery.

Trichotillomania is a psychological condition where a person has an urge to pull or twist their hair until it comes out.

How common is hair loss?

Male-pattern baldness is more common than female-pattern baldness, affecting around half of all men at some point.

Female-pattern baldness becomes more common in women over 40 years old, particularly after the menopause(when a woman’s periods stop at around age 52).

Alopecia areata will affect one or two people in every 100 over the course of their lifetime. Up to 1 in 5 people with alopecia areata have a family member with the condition. This suggests that it can run in families in some cases.

Outlook

Minoxidil is used to treat male-pattern and female-pattern baldness. The treatment is usually only effective for as long as it is continued. It tends to slow hair loss rather than stop or reverse it completely. See Hair loss – treatment for more information.

Most people with alopecia areata can expect their hair to grow back within 12 months without any specific treatment. However, the hair loss may return sometime in the future.

Up to a quarter of people with alopecia areata will experience significant hair loss of more than half the hair on their scalp. In around 1 in 14 people, alopecia areata will progress to the more severe forms known as alopecia totalis or alopecia universalis (see above).

If you have significant hair loss of any type, you may decide to wear a wig.

If you are finding it difficult to come to terms with losing your hair, you may benefit from joining a support group or speaking to other people in the same situation – for example, through online forums.  www.Alopeciaireland.ieprovide these services.