Trichoscopy
Trichoscopy is dermoscopic examination of the scalp, using magnification and controlled lighting to assess hair shafts, follicular openings and the surrounding skin without a biopsy. It is the first-line examination for most hair loss and the standard way to judge whether a donor area is stable.
Trichoscopy is dermoscopy applied to the scalp. A magnifying lens with controlled lighting is held against the skin so hair shafts, follicular openings and the surface around them can be examined directly. Nothing is removed and nothing is cut — it replaced the scalp biopsy as the first-line examination for most hair loss.
The finding that carries the most weight is variation in shaft thickness. A healthy scalp grows hairs of broadly similar calibre. Where follicles are miniaturizing, thick and thin shafts sit side by side. Hair diameter variability was present in the large majority of patients with pattern loss reviewed systematically, with thresholds of more than 20% variation in men and more than 10% in women (Kuczara et al., Journal of Clinical Medicine, 2024).
| Finding | What it indicates |
|---|---|
| Hair diameter variability | Miniaturization; the most sensitive sign |
| Peripilar sign | A brown halo at the opening; highly specific |
| Vellus hairs | Advanced miniaturization in the area |
| Yellow dots | Openings filled with keratotic material |
| Loss of openings | Points away from pattern loss entirely |
Its most useful application in surgery is the donor area. A dense-looking occiput can already contain miniaturizing hairs, and that is invisible without magnification. Examining the back of the head, not just the top, is what separates a stable donor from one that only looks stable.
Related terms
For how the donor region is judged before planning, see the donor area guide. For staging a visible pattern, see the Norwood scale.
