located at disorder dermatological-mucosal system rash Vaccine, 25 (2007) 5697-5706 A morphologically described change in the appearance of the skin or mucosa that occurs in the context of and in conjunction with an emerging allergic event that consists of one or more clearly identified primary lesion(s) (macule, papule, vesicle, nodule, bulla, cyst, plaque, pustule) and/or secondary skin change(s) (scaling, atrophy, ulcer, fissure, excoriation).