Cosmetic alteration of a patient's orbital skin is a common reason for professional consultation. This review presents the differential diagnosis and recommended evaluation of inflamed eyelids. To better understand the diseases, each is individually addressed clinically, pathogenetically, and therapeutically. It is critical to recognize the lesions correctly and to have full knowledge of the putative clinical disease process. An algorithm for an appropriate work-up for each disease is offered. With this background, a successful therapeutic response can be anticipated.