RESUMEN
ObjectiveTo explore the distribution of traditional Chinese medicine （TCM） syndromes of alopecia areata （AA）， and to provide reference for TCM clinical syndrome differentiation and classification of AA. MethodsAA patients who visited the specialized hairiness clinic of Beijing China-Japan Friendship Hospital were included. A questionnaire was developed including general information of the patients， history of hair loss （onset time， triggers and exacerbating factors， disease progression）， current symptoms （symptoms and signs）， medical history， personal history， family history， and hair microscopy examination results. The factor analysis and cluster analysis were used to determine the syndrome elements and to summarize the syndrome types. ResultsA total of 600 patients with AA were included， including 218 males （36.33%） and 382 females （63.67%）. Totally， 128 patients （21.33%） had a family history of hair loss， and 326 patients （54.33%） had a previous related underlying disease. The leading triggering and exacerbating factors of AA were tension and anxiety， accounting for 335 cases （55.83%） and 285 cases （47.50%）， respectively. The top 10 symptoms involved among patients were scalp oil， anxiety， irritability， dreaminess， fatigue， itching， tension， weakness and dandruff. The factor analysis showed that the factor rotation converged after 9 iterations， and finally obtained 12 common factors and 34 variables， with a cumulative contribution rate of 58.59%. In terms of disease location of AA， the main syndrome elements were liver， spleen and kidney， and the disease nature syndrome elements were mainly dampness-heat， qi stagnation， yin deficiency， qi deficiency， and blood deficiency. The clustering analysis of the 12 common factors showed that TCM syndromes could be summarized into four categories： internal retention of damp-heat， liver-kidney deficiency， qi and blood deficiency， and liver constraint and spleen deficiency. There were significant differences in the distribution of TCM syndromes in patients of different ages and genders （P＜0.001）. ConclusionThe main disease location of AA is in the liver， spleen， and kidney， with the liver being the key. The disease mechanism of AA is a deficiency-excess complex， initially manifested as excess and later becoming deficiency. The TCM syndromes mainly include four types which are internal retention of damp-heat， liver-kidney deficiency， qi and blood deficiency， and liver constraint and spleen deficiency.