Photodermatitis, sometimes referred to as sun poisoning or photoallergy, is a form of allergic contact dermatitis in which the allergen must be activated by light to sensitize the allergic response, and to cause a rash or other systemic effects on subsequent exposure. It is distinct from sunburn.
光過敏是指因陽光照射而引發或加重的各種症狀、疾病與病症（光性皮膚病）。它可分為五類：primary photodermatosis（原發性光皮膚病）、exogenous photodermatosis（外源性光皮膚病）、photo‑exacerbated dermatoses（光惡化性皮膚病）、metabolic photodermatosis（代謝性光皮膚病）以及 genetic photodermatosis（遺傳性光皮膚病）。 Photosensitivity refers to various symptoms, diseases, and conditions (photodermatoses) caused or exacerbated by exposure to sunlight. It is classified into five categories: primary photodermatosis, exogenous photodermatosis, photo-exacerbated dermatoses, metabolic photodermatosis, and genetic photodermatosis.
光敏性皮炎 (photosensitive dermatitis) 可能導致腫脹、呼吸困難、灼熱感、紅色發癢皮疹（有時呈小水泡狀）以及皮膚脫皮。亦可能出現斑點，搔癢感可能持續較長時間。