Hair Follicles of Anterior Parietal Region are More Vulnerable than Occipital Region in Classic Acute Telogen Effluvium

Background: The well known clinical feature of the classic acute telogen effluvium is diffuse hair loss from all over the scalp and the diagnosis is confirmed by a trichogram showing an increased telogen count. While the telogen hair shedding continues, newly cycled back young anagen hairs develop in the involved scalp. Objective: To see if there is a regional difference in the numbers of the involved hair follicles in that seemingly diffuse hair loss. Methods: In 7 cases of the telogen effluvium, the telogen count was done at two sites, anterior parietal and occipital. During the count, the short tapered anagen hairs(<1cm) which developed during the course of the telogen effluvium were counted together and compared according to the regions. Results: The sum of the short anagen hairs and the telogen hairs was 50.3% in anterior parietal area, whereas it was 31.6% in occipital area(p<0.0l). Conclusion: Hair follicles in anterior scalp appear to be more vulnerable than occipital scalp in the acute telogen effluvium.