A 35-year-old woman presented with generalized hair thinning and hair loss that had begun 1 month prior. She was generally healthy but reported chronic constipation and anxiety. About 1 month prior, her sertraline dose had been increased from 50 to 100 mg. She did not braid her hair, wear tight ponytails, or use restrictive hair bands. She did not have recent illness, lightheadedness, menorrhagia, arthralgias, weight gain, rash, or personal or family history of autoimmune conditions.

Her vital signs were normal. Physical examination revealed diffuse hair thinning across the scalp (Figure 1). No broken hairs, rash, scaling, or scarring were present. A hair pull test was positive for hair loss. The patient had no noticeable facial hair.

QUESTION

Based on the patient's history and physical examination, which one of the following is the most likely diagnosis?

• A. Alopecia areata.

• B. Androgenic alopecia.

• C. Telogen effluvium.

• D. Traction alopecia.

DISCUSSION

The answer is C: telogen effluvium, the second most common cause of nonscarring hair loss after androgenic alopecia. In telogen effluvium, large swathes of hair follicles transition from the anagen phase to the telogen (resting) phase of the growth cycle. This is typically caused by an internal or environmental stressor; however, many cases of telogen effluvium are idiopathic.