Huo Xiang Zheng Qi includes Huo Xiang Zheng Qi Water, Huo Xiang Zheng Qi Pill and Huo Xiang Zheng Qi San, which are different dosage forms of one medicine. The function of Huo Xiang Zheng Qi is to relieve symptoms and neutralize dampness, and it is mainly used to treat cold, fever, headache, chest and diaphragm fullness, heart and abdominal pain, nausea, vomiting, intestinal tinnitus, diarrhea, etc. caused by external wind and cold, internal dampness and stagnation, which means it is most commonly used to treat gastrointestinal colds. Patchouli can treat many diseases in dermatology, such as acute eczema, subacute eczema, papular urticaria, gastrointestinal urticaria, and some polymorphic sun rashes, mosquito bites, summer dermatitis, etc. All these diseases must have symptoms of gastrointestinal damp-heat, such as chest and stomach fullness, nausea, vomiting, intestinal tinnitus, diarrhea, in addition, the tongue can be white and greasy, and if a rash develops, it can be oozing, crusty and itchy. However, in clinical practice, we also need to add and subtract to identify the evidence, and add and subtract different medicines according to different symptoms, just using Huo Xiang Zheng Qi alone to treat eczema is not enough.