Regional Differences in Scalp Innervation: A Pilot Study of the Healthy Scalp
TLDR The back of the scalp has more nerve fibers than the front, which may explain why some people feel more sensitivity there.
In a pilot study conducted on seven healthy individuals aged 20-40 with Fitzpatrick skin types 2-4, researchers aimed to quantify the epidermal nerve fiber (ENF) density in the occipital and frontoparietal regions of the scalp. This was motivated by observations that patients with alopecia areata (AA) and lichen planopilaris (LPP) experience different levels of pain in various scalp regions, and a lack of baseline ENF density data for comparison. The study involved taking two 4-mm scalp biopsy specimens from each region of each participant, which were then immunostained and analyzed using tracing software. Results showed a significantly higher ENF density in the occipital scalp, with 109.3 ENF/mm, compared to the frontoparietal scalp, which had 36.0 ENF/mm (p = 0.0009). These findings suggest a reason for increased sensitivity in the occipital scalp for some patients and serve as initial data for creating a database on healthy scalp innervation. Future research is planned to include a broader range of ages and skin types.
