The methods, compositions, and assays described herein are based, in part, on the discovery that CD1a mediates inflammation related to certain conditions such as urushiol exposure, psoriasis and other inflammatory skin diseases. One aspect provided herein relates to a method for treating or preventing an inflammatory skin disease, the method comprising: administering a therapeutically effective amount of an inhibitor of CD 1a to a subject having an inflammatory skin disease, thereby treating or preventing the inflammatory skin diseases.
