Establishment and validation of a hair fall atlas for Chinese men based on trichoscopy

Abstract Background Hair loss is among the top concerns for Chinese men. Current clinical diagnosis is based on the Hamilton‐Norwood classification as a macroscopic tool to recognise different severity levels and the phototrichogram (PTG) to show hair regrowth status within a shaved zone. However, it has limited dynamics and sensitivity to assess consumers with mild hair loss problems or at the early onset of hair loss. Therefore, we aim to develop a zoom‐in hair fall atlas based on trichoscopy to better evaluate consumer hair fall problems. Methods Four hundred healthy Chinese men with different hair fall severity of Hamilton‐Norwood classification are recruited, pictures collected and scalp measurements conducted in a total of 3 days. Later, 5 dermatologists will select representative images to build the atlas and score the rest of the images accordingly. Results A hair fall atlas based on scalp micro images was established, with 7 grades to represent the wide variety of consumer hair‐fall severities. Each dermatologist scored images that covered all the grades. Good consistency was achieved between the 5 dermatologists ( Pearson correlation coefficient >0.8). Our results also showed great repeatability between two scores of the same dermatologist ( intraclass correlation coefficient >0.9). In addition, a strong correlation was shown between clinical scores and hair fall attributes of scalp visibility % and hair diameter based on image analysis ( |p| > 0.8). Conclusion The FISHS hair fall atlas is well‐established, validated and ready to be incorporated as a new methodology to guide anti‐hair fall evaluation and aid in product development.