Trichoscopy and Donor Assessment Before Hair Transplantation

Definition and clinical context

Trichoscopy examines the scalp and hair shafts under magnification. A donor area that looks dense in a photograph may show fine shafts or regional density differences when examined this way.[1][2]

Biological and surgical significance

Follicular unit density (FU/cm²), hair density (hairs/cm²), hairs per unit, shaft diameter and diameter variation should be measured separately. Assessment at several occipital and lateral sites is more informative than relying on one point.[1][2]

Assessment and planning

Conditions that mimic androgenetic alopecia, including alopecia areata incognita and inflammatory or scarring alopecias, may alter surgical suitability. Yellow dots or peripilar casts can be diagnostic clues, but they are not a diagnosis on their own.[1][2]

Limits of the evidence

Magnification, illumination, hair length and the measured area affect the result. A device measurement cannot predict future hair loss with certainty.[1][2]

KSD planning note

Trichoscopic findings are recorded before setting a harvesting target. Regional measurements and diagnostic concerns are considered separately; using a suspicious area simply to obtain more grafts is inappropriate.

Topic-specific questions

Is trichoscopy the same as photography?

No. Magnification helps assess shaft diameter, unit structure and scalp findings; standard photographs complement this assessment.

Does a yellow dot establish a diagnosis?

No. History, distribution and other trichoscopic findings must be considered together, with additional investigation when needed.

References

For medical information; not a substitute for an individual examination.