Review Question - QID 102987

This patient exhibits alopecia areata, recurrent patchy hair loss, typically affecting the scalp but may occur on any hair-bearing part of the body. Alopecia areata is associated with autoimmune conditions including autoimmune thyroid disease, vitiligo, atopic dermatitis, collagen vascular disease, asthma, rheumatoid arthritis, lupus, or seasonal allergies.

Alopecia areata presents as rapid (several weeks) hair loss resulting in bald spots on the scalp. There are smooth hairless patches surrounded by 'exclamation-point' hairs. Treatment, including topical and oral steroids, minoxidil, cyclosporine, and photo-therapy may temporarily induce hair growth; however, these treatment modalities do not affect the disease course, as hair loss typically recurs once treatment is halted. Often the disease resolves spontaneously without treatment.

Mounsey et al. discuss the diagnosis and treatment of hair loss. Alopecia areata has an overall prevalence of 0.1% and an individual lifetime risk of 1.7%. Men and women are equally affected with between 30-50% of patients exhibiting symptoms before age 20. There is probable polygenic inheritance of the disease, as 20-40% of patients have a family history of the disease. Diagnosis is typically clinical; however, skin biopsy may confirm the diagnosis by showing numerous lymphocytes.

Betz et al. conduct a meta-analysis of potential genetic associations in alopecia areata. Numerous genetic loci are implicated, with the strongest association occurring in the major histocompatibility complex HLA-DR. As suggested by the genetic susceptability loci identified, biochemical and cellular processes that are disrupted in alopecia areata include apoptosis, TGF-beta signaling, and JAK kinase signaling. The disruption of these processes supports the autoimmune etiology of alopecia areata.

Figure A is an image of a patient suffering from alopecia areata; note the multiple patchy bald spots on the scalp. Illustration A summarizes a proposed pathogenetic mechanism in alopecia areata; note that the normal hair follicle is considered to be an immune-privileged organ. Illustration B shows the 'exclamation point' hairs that surround bald patches in alopecia areata; note the thinned proximal hair shaft and club-shaped root.

Incorrect Answers:
Answer 1: Type II diabetes is not associated with alopecia areata; however, type I diabetes, with its autoimmune basis may have a small association with the condition.
Answer 2: Migraine headaches are not associated with alopecia areata.
Answer 3: Scoliosis is not associated with alopecia areata.
Answer 4: Gonococcal arthritis is not associated with alopecia areata, as it is an acquired infection and not an autoimmune condition.