Director
University of British Columbia Hair Research and Treatment Centre
Vancouver Hospital and Health Sciences Centre.
Presented at the International NAAF Conference, Seattle, Washington, Saturday, July 6,1996
Epidemiology: (Study of the rate of occurrence of a particular condition.) According to a recent study from the Mayo Clinic, the lifetime incidence rate of alopecia areata is 1.7% which makes it almost as common as psoriasis. Sixty percent of patients usually present with their first patch under the age of 20. Twenty percent present with their first patch over the age of 40 and twelve percent present with their first patch past the age of 50.
One can classify alopecia areata based on extent of disease or pattern of hair loss. Alopecia areata usually refers to varying amounts of patchy hair loss to larger areas of little or no hair: this kind of hair loss generally takes place on the scalp, but any hair-bearing surface can be affected. In alopecia totalis, all the scalp hair on the scalp is lost, and the surface of the scalp becomes totally smooth. Alopecia universalis means loss of all hair on the head and body, including eyelashes, eyebrows, underarm hair, and pubic hair. Practical problems of alopecia universalis are 1 ) without eyebrows, perspiration trickles into the eyes 2) without eyelashes, there is little protection from dust and glare 3) without nasal hairs, there is no protection in the nostrils or sinuses from foreign particles in the air. Alopecia areata can also be classified by the pattern of hair loss. Circumscript type means localized patch of hair loss. Reticulated type means that is there is a net-like pattern of hair loss in which irregular areas without hair are interspersed with areas of hair on the scalp. Ophiasiscomes from the Greek word serpent. It is a pattern of hair loss that covers the periphery of the scalp like a serpent forming a turban over the edges of the scalp. This type of hair loss is more difficult to treat and this area of the scalp is more sluggish to treatment. Diffuse form of alopecia areata means a form of incomplete hair loss affecting the whole scalp without distinct patches. This type can be difficult to diagnose and may require a biopsy. To help in the diagnosis of any type of alopecia areata, the dermatologist always looks for exclamation point hairs- broken off short hair that taper (get narrower) toward the scalp.
Most people who have alopecia areata do not have any other medical condition, but a small proportion do. The exact nature of the association between these other medical conditions is not clear, but the association is considered correlational and not causal; that is we can say there is a link between alopecia areata and another condition; but we cannot say that one condition causes the other.
Atopy means having a genetic predisposition toward developing hayfever, asthma, and eczema. Patients who have atopy and alopecia areata are more likely to have a more severe or resistant form of alopecia areata.
There is a correlation between alopecia areata and thyroid disease. Eight percent of people with alopecia areata have thyroid disease; this is higher than the incidence of thyroid disease in the general population which is 2%. But even though there is a correlation between alopecia areata and thyroid disease, treating the thyroid disease does not remedy the alopecia areata.
Vitiligo is a condition involving loss of pigment in the skin in patches which may affect varying areas of the body. It occurs four times more frequently in alopecia areata patients compared to the general population. Because vitiligo is more likely to develop on irritated skin, someone who has both alopecia areata and vitiligo may not be able to pursue certain treatment options for alopecia areata. Immunotherapy with diphenylcyclopropenone, for example, irritates the skin and thus might make it more likely that vitiligo will appear in that area of the body.
Case studies have been reported of persons with alopecia areata who have developed other autoimmune diseases such as lupus erythematosus, rheumatoid arthritis, pernicious anemia, scleroderma and ulcerative colitis. The chances of someone with alopecia areata developing one of these diseases is very low and routine lab tests for these diseases are not indicated. However, if a patient with alopecia areata develops unexplained medical symptoms, he or she should go to their doctor and ask if their hair condition might be related. There appears to be a higher incidence of diabetes mellitus and rheumatoid arthritis in the family members of patients with alopecia areata rather than the actual patients with alopecia areata.
The most typical aspect of alopecia areata is its unpredictability. It is truly impossible for a physician in 1996 to tell a patient with alopecia areata what is in store for them. The statistics we know are: 50% of patients regrow their hair within the first year of presentation without treatment. Seven to ten percent have very severe disease. Patients with atopy or ophiasis usually have a poorer prognosis. If the initial presentation is in childhood, these patients usually do not do as well as those patients who have their first presentation as adults.
Treatment is based on two criteria: a) extent of disease and b) age.
Patients are divided into two groups: 1) less than 50% scalp hair loss and 2) more than 50% scalp hair loss.
Topical immunotherapy has a 50% chance of producing cosmetically acceptable regrowth. It is not yet approved in the USA. The NIH has commenced a study on a limited number of patients. The longer one has the disease and the greater severity of the disease, the smaller the chance of success. Side effects are eczema, lymph node enlargement and change in pigment of the skin.
Our aim is to have a specific treatment that can block the immunologic event(s) that are responsible for alopecia areata. Newer immunomodulators are being developed that may inactivate or block receptors in this "immunologic soup" that is causing alopecia areata. Phototherapy with novel light sources, such as the laser, in combination with photosensitizing agents may be able to "tickle" the hair follicle to start growing hair again. Combination treatments will be used more commonly. Alopecia areata is a heterogeneous disease in the same patient and may require multiple modalities to regrow hair on differing portions of the scalp.