Distinguishing the cause of itching, red eyelids is often difficult. Pruritic, inflamed eyelids can reflect various etiologies and are a common clinical presentation to the office of a dermatologist or ophthalmologist. In this article, five of the more common causes of eyelid dermatitis (atopic dermatitis, contact dermatitis, contact urticaria, rosacea, seborrhea, and psoriasis) are reviewed in detail, with particular emphasis on the ocular and periocular features. Clinical clues, historical features, and patch testing in cases of eczematous eyelid dermatitis aid in differential diagnosis. In addition, pathogenesis and treatment are reviewed.