Dermatomyositis is a systemic autoimmune disease that involves the skin and skeletal muscle. The clinical manifestations are mainly skin rash, muscle weakness, and myalgia. This disease early exogenous six evil spirit, into the heat into poison, evil poison accumulation block the skin and hair; Long disease viscera essence qi loss, thin muscles, limb weakness.Professor Tang Xiaohu according to the years of clinical experience, the acute phase of heat poison is partial, to clear heat and detoxify, promote blood circulation and relieve pain. Heat poison trap heart camp, to clear camp detoxification, heat nourishing Yin. Remission period to damp and heat, to clear heat and dampness, promote the meridians. Blood stasis and heat are heavy, to promote blood circulation and remove blood stasis, regulate qi and invigorate the spleen. Chronic period of Qi and blood deficiency, to benefit the temperature meridian, nourishing blood and collaterals. Yin and Yang imbalance, Yin deficiency is heavy, to nourish the liver and kidney, nourishing qi and Yin.Yang deficiency is more severe, with the aim of warming yang and unblocking collaterals, strengthening the spleen and tonifying the kidneys.During temporary treatment, the pathological factors were identified and the drug was precise. This article takes the example of acute heat toxicity, and elaborates on the combination of Qingying Tang and Qinghao Biejia Tang with modifications.