Alopecia refers to loss of hair. There are various kinds of hair loss conditions, including alopecia areata and alopecia universalis.

The former refers to hair loss in patches anywhere on the body, while the latter is a severe form of alopecia areata and results in the total loss of hair from the entire body.

An auto-immune disease, alopecia universalis affects one in 100,000 people. Genetic factors may play a role in its occurrence and stress may precipitate it as well.

Other factors like nutritional deficiency may also come into play.

Dr Tan Kian Teo, a consultant dermatologist at the National Skin Centre, said that alopecia universalis is uncommon before the age of one.

Patients with alopecia universalis may experience hair regrowth but this hair may fall out again.

There are two main forms of treatment to induce hair regrowth: topical immunotherapy, using the potent contact allergen diphencyprone, and phototherapy.

Topical immunotherapy involves diphencyprone being applied on bald areas once a week.

In alopecia universalis, immune cells attack hair follicles, causing hair loss. It is not known how diphencyprone works exactly but it is thought to help divert immune cells to the skin, thus allowing the hair to regrow.

Phototherapy involves treating bald areas twice a week with ultraviolet-A light and a photo-sensitising agent. It works by suppressing the immune cells.

Dr Tan said 30 to 40 per cent of patients respond favourably to treatment but added: 'Even if there is a favourable response, it is possible that hair loss can recur.'

When asked what problems children with alopecia universalis face, Dr Tan said that the condition usually has little impact on preschoolers for whom physical appearance is not important.

He said: 'There may be problems when they are of school-going age as they will be more aware of their looks and more self-conscious.

'Educating the child and the parents is important. It will also help to educate the child's teacher and classmates so that they understand the condition. One will be surprised at how well children can cope and how resilient they are.'

This article was first published in Mind Your Body, The Straits Times.