fotosensitisasi

Fotosensitisasi is a condition where exposure to light, particularly ultraviolet (UV) radiation, triggers or exacerbates certain skin reactions. It can manifest in various ways, ranging from mild rashes to more severe blistering and inflammation. There are two main types: photoallergic and phototoxic reactions. Photoallergic reactions involve an immune system response, where a substance, often a medication or topical agent, is altered by UV light to become an allergen. The immune system then reacts to this altered substance. Phototoxic reactions, on the other hand, are a direct result of a substance absorbing light energy and releasing it in a way that damages skin cells. This type of reaction does not involve the immune system and can occur with higher doses of the offending substance and light.

Common causes of fotosensitisasi include certain medications, both topical and systemic, such as antibiotics, diuretics, and nonsteroidal anti-inflammatory drugs (NSAIDs). Some plants, particularly those in the citrus family (like limes and bergamot), contain compounds called psoralens that can cause phytophotodermatitis, a type of phototoxic reaction when skin comes into contact with the plant and is then exposed to sunlight. Early identification of the causative agent is crucial for managing fotosensitisasi. Treatment typically involves avoiding further exposure to the offending substance and light, and symptomatic relief with topical corticosteroids or oral antihistamines for itching. Photoprotection, using broad-spectrum sunscreen and protective clothing, is essential for individuals prone to these reactions.