Alopecia areata is a disorder of unknown origin which is responsible for the loss of hair (alopecia) in patches (areata). If affects persons of all ages but is more common in young people. The patches vary in number from one to six or more and at first are about the size of a finger nail. They gradually enlarge and not uncommonly fuse to form large irregular areas. Usually all the hair in the patches is absent, a white, shiny scalp being seen in these areas. If the patches are spreading, numerous hair stumps about a quarter of an inch in length are seen at the edge. These hairs are much wider and more heavily pigmented where they are broken off than at the points where they enter the hair follicles. This phenomenon gives them the appearance of exclamation points, and they are therefore called "exclamation-point hairs."
When the patches are no longer spreading and the hair is growing again in the areas, the exclamation-point hairs are not found. There is never any redness, scaling, or other sign of inflammation, and there are no subjective symptoms. Rarely is the hair of other areas affected, notably the bearded region, eyebrows, eyelashes, and armpits. In rare instances, the entire body becomes devoid of hair, and one sometimes sees total alopecia of the scalp in the absence of involvement elsewhere. The cases which present total alopecia are probably most common in children, and these are the most resistant to treatment.
There is good evidence that the disorder is related in some way to the nervous system. If the alopecia is total, it can frequently be demonstrated that there is some derangement of the glands of internal secretion or that congenital syphilis is a factor. As stated, the hair practically always comes back, the exception being the cases of total alopecia in children, and even in some of these instances the hair can be entirely restored.
Because of the numerous possibilities as to the causative factors in this disorder, each case is an individual problem and can therefore be worked out only by the painstaking efforts of a physician. The local treatment consists in the use of stimulating ointments and lotions and sometimes the irradiation of the scalp with ultraviolet rays and other measures. The case of the individual's general health is of the utmost importance.
It is important that this disorder be differentiated from the causes of baldness which are infectious and require isolation, such as ringworm.
by Clark W. Finnerud
Common Skin Diseases of Children
The Anatomical Structure of the Skin
