Fotoallergilised

Fotoallergiline, also known as photoallergic reaction, is a type of skin inflammation that occurs when a substance applied to the skin, or taken internally, is exposed to ultraviolet (UV) radiation, typically from sunlight. This interaction triggers an abnormal immune response in the skin. Unlike phototoxic reactions, photoallergic reactions are not dose-dependent, meaning even a small amount of the causative agent and UV light can provoke a reaction. The reaction is also delayed, often appearing 24 to 72 hours after exposure to both the agent and UV light.

The symptoms of a fotoallergiline reaction usually manifest as an eczematous eruption, characterized by redness, itching, swelling, and sometimes blistering. The affected areas are typically those exposed to sunlight, such as the face, neck, arms, and hands. The rash can spread to areas not directly exposed to light due to the circulation of the photosensitizing agent in the body.

Common culprits for fotoallergiline reactions include certain topical medications like sunscreens containing PABA (para-aminobenzoic acid) or oxybenzone, fragrances, and some industrial chemicals. Systemic medications, such as certain antibiotics, anti-inflammatory drugs, and diuretics, can also cause photoallergic reactions when their metabolites are exposed to UV light in the skin. Diagnosis is usually made based on the patient's history, the pattern of the rash, and a photopatch test, where the suspected agent is applied to the skin and then exposed to UV light to see if a reaction occurs. Management involves identifying and avoiding the causative agent and protecting the skin from sunlight.