A 30-year-old woman presents with diffuse hair loss 3 months after childbirth. Pull test is positive with 8 hairs, and the telogen-to-anagen ratio on trichogram is 40:60. The mechanism of this type of hair loss is:

• A Premature follicular anagen arrest causing immediate shedding
• B Autoimmune attack on anagen follicles causing abrupt hair loss
• C Miniaturization of follicles due to hormonal androgenization
• D Synchronization of follicles into telogen phase during pregnancy followed by simultaneous shedding at parturition ✓

Explanation

Postpartum telogen effluvium results from synchronized premature entry of anagen follicles into telogen during the final trimester of pregnancy (elevated estrogens prolong anagen). After parturition and hormonal withdrawal, these synchronized follicles simultaneously enter telogen and shed 2-5 months later. The diffuse shedding is self-limiting, resolving within 6-12 months. Trichogram shows elevated telogen count (>25%). This differs from alopecia areata (autoimmune, exclamation mark hairs) and androgenetic alopecia (patterned miniaturization).

Reference: Neena Khanna Illustrated Synopsis of Dermatology & STD, 6th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.