This is a 28-year-old female patient who suffered from overall rashes in 1997 and was diagnosed with Pityriasis Lichenoides. She was treated with Western medication with no success and a sudden increase of body weight so that she turned to traditional Chinese medicine for help. She was treated with formulas to c1ear heat, cool blood, disperse wind and dry dampness due to her wind-cal1lp-heat pattern. The patient was fully recovered with previous body weight and has stopped taking herbs for nearly 3 months without any relapse. In Feb. 1998, the patient started to have skin papules and visited again. The treatl1lent principle was the same as previous one, and the patient has no re]apse every since with normal body weight. This article is to discuss the etiology, mechanism and herbal formal involved in this successful case.