Hair Follicles of Anterior Parietal Region Are More Vulnerable Than Occipital Region in Classic Acute Telogen Effluvium

A study conducted 21 years ago on 7 cases of acute telogen effluvium, a condition characterized by diffuse hair loss, found regional differences in the vulnerability of hair follicles. The researchers compared the telogen count (the number of hairs in the resting phase of the hair growth cycle) in the anterior parietal and occipital areas of the scalp. They found that the sum of short anagen hairs (those in the active growth phase) and telogen hairs was 50.3% in the anterior parietal area, compared to 31.6% in the occipital area. This suggests that hair follicles in the anterior scalp were more vulnerable than those in the occipital scalp in cases of acute telogen effluvium.