Distinguishing androgenetic alopecia from chronic telogen effluvium when associated in the same patient: A simple noninvasive method

Abstract

Background: Distinguishing chronic telogen effluvium (CTE) from androgenetic alopecia (AGA) may be difficult especially when associated in the same patient. Observations: One hundred consecutive patients with hair loss who were clinically diagnosed as having CTE, AGA, AGA+CTE, or remitting CTE. Patients washed their hair in the sink in a standardized way. All shed hairs were counted and divided "blindly" into 5 cm or longer, intermediate length (>3 to <5 cm), and 3 cm or shorter. The latter were considered telogen vellus hairs, and patients having at least 10% of them were classified as having AGA. We assumed that patients shedding 200 hairs or more had CTE. The κ statistic revealed, however, that the best concordance between clinical and numerical diagnosis (κ=0.527) was obtained by setting the cutoff shedding value at 100 hairs or more. Of the 100 patients, 18 with 10% or more of hairs that were 3 cm or shorter and who shed fewer than 100 hairs were diagnosed as having AGA; 34 with fewer than 10% of hairs that were 3 cm or shorter and who shed at least 100 hairs were diagnosed as having CTE; 34 with 10% or more of hairs that were 3 cm or shorter and who shed at least 100 hairs were diagnosed as having AGA + CTE; and 14 with fewer than 10% of hairs that were 3 cm or shorter and who shed fewer than 100 hairs were diagnosed as having CTE in remission. Conclusion: This method is simple, noninvasive, and suitable for office evaluation. ©2005 American Medical Association. All rights reserved.