Objective  To analyze the prescription regularity of Chinese medicine in treating eczema based on data mining technology.

  Methods  A total of 1 214 literatures on the treatment of eczema with traditional Chinese medicine were searched in the past 20 years from China National Knowledge Internet (CNKI) and Wanfang Academic Journal Full-text Database. Excel software was used to establish a database to analyze the medication frequency and high frequency distribution of drug odor; eczema with severe pruritus syndrome differentiation of medication was analysed; Spss Modeler software was used to explore association rules and prescription rules of eczema medication based on association rules Apriori algorithm, and the rules were visualized through network.

  Results  A total of 584 literatures and 970 prescriptions involving 454 Chinese herbal medicines. Among them, the most frequently used herba of oral decoction were Gancao, Baixianpi, Shengdihuang as well as Kushen and so on; the drugs with high frequency of external prescriptions for external use were Kushen, Huangbai, Difuzi, Shechuangzi, as well as Baixianpi and so on; the drug properties of high-frequency drugs were mainly "cold or slightly cold"; the tastes of medicine were mainly bitter and sweet, mainly belonged to the "liver, lung, spleen" meridians; the drugs with high frequency of dialectical addition and subtraction in eczema patients with severe pruritus were Difuzi, Baixianpi as well as Wushaoshe and so on. Association rules showed that the core drug pairs were Zhizi-Gancao, Huangbai-Baixianpi-Kushen, Jingjie-Fangfeng, Shechuangzi-Difuzi-Kushen and Baixianpi-Difuzi-Kushen.

  Conclusion  In the prescription of traditional Chinese medicine for treating eczema, heat clearing drugs, relieving surface drugs, benefiting water infiltration and dampness drugs, attacking toxin, killing insects and relieving itching drugs are the main drugs. The drugs with high frequency of use are Gancao, Baixianpi, Jingjie, Fangfeng as well as Kushen and so on.