3 stages of the physical exam
All hair-bearing sites should be examined. Clinical examination should be performed in 3 stages:1,2
- Inspect the scalp for inflammation, scale, and erythema to determine whether scarring is present.
- Examine the hair density and distribution pattern.
- Study the hair shaft quality, looking at caliber, fragility, length, and shape.
The “pull test” is often used to assess ongoing hair loss. If more than 10% of hairs are pulled away from the scalp, the test is positive, suggesting active hair shedding.1
Beyond the history and physical
Ancillary laboratory evaluation is sometimes necessary if the diagnosis remains unclear.1,2 Serum ferritin or a complete blood count can be useful to look for iron-deficiency anemia; a thyroid-stimulating hormone test can rule out hypothyroidism.3 According to 1 small study of 50 women with diffuse alopecia, thyroid tests are not routinely warranted without supportive clinical signs.4
Check free testosterone, androstenedione, and dehydroepiandrosterone if virilizing signs are present, to assess hyperandrogenism.1,3 Serum prolactin can be useful if the patient has galactorrhea.5 Also, consider a Venereal Disease Research Laboratory test to rule out syphilis.2,6
No evidence suggests that low serum zinc concentrations cause hair loss. In fact, excessive intake of nutritional supplements may lead to hair loss and aren’t recommended in the absence of a proven deficiency.7
If a patient has scarring alopecia, a scalp biopsy is almost always necessary to make a diagnosis.1 Usually a punch biopsy is sufficient, but it should be no smaller than 4 mm. The preferred location is the central scalp in an area representative of the hair loss.1,5
Recommendations
The University of Texas Family Nurse Practitioner Program recommends a thorough history and physical examination and, if indicated, selected laboratory evaluation.6 The program states that the Women’s Androgenetic Alopecia Quality of Life (WAA-QOL) Questionnaire is useful in evaluating health-related quality of life specific to women.
The American Hair Loss Association recommends checking some screening labs on women with hair loss, but states that the diagnosis is usually a process of elimination as many of the laboratory tests mentioned above will come back in the normal range.8