Hair loss is a common problem that can have severe psychological effects in younger patients. The patient in the above vignette appears to be suffering from alopecia areata. It is a relatively common disease and is characterized by discrete, smooth and circular areas of hair loss over the scalp. There is typically no associated scaling or inflammation present in the area of hair loss. The hair loss usually develops over a few weeks and has a recurring pattern. Most of the patients will have regrowth of the hair in the involved areas over time.
The exact etiology of alopecia areata is unknown. An autoimmune process is thought to play at least a partial role in its pathogenesis. This is supported by the finding of T-cell infiltration around the hair follicles and the association of other autoimmune conditions (i.e., pernicious anemia, vitiligo, and thyroid diseases) with alopecia areata. The disease can recur in up to one-third of these patients. Some factors associated with the higher chance of relapse include a longer duration of the disease, a more extensive disease, involvement of peripheral areas, and onset prior to puberty.
Topical or intralesional corticosteroids are the treatment of choice for patients with alopecia areata. Patient education and information is also the key part of treatment. Patients should be made aware that: (1) the disease is usually benign, (2) they can have multiple relapses in spite of treatment, and (3) most patients have normal hair growth within the next one to two years even without treatment. They should also be informed that treatment with steroids, either intralesional or topical, can restore normal hair growth but does not cure the disease. After a steroid injection, new hair growth is usually seen in the next four to six weeks.
Patients with tinea capitis have an associated scaling and inflammation of the scalp in the areas of hair loss.
Localized discoid lupus erythematosus of the scalp causes hair loss, scaling, inflammation, scarring, and hypopigmentation of the skin. There may be associated lesions present over the face or extremities.
Areas of hair loss in secondary syphilis are not smooth and discrete. The lesions usually have a "moth-eaten" appearance and are associated with significant scarring.
Hair loss in men with androgenetic alopecia starts in the frontal or temporal areas and progresses gradually (male pattern baldness).