Fototoxicitet

Fototoxicitet, also known as photoallergy or photodermatitis, is a skin reaction that occurs when skin is exposed to sunlight or artificial ultraviolet (UV) radiation. This reaction is triggered by the interaction of certain substances with UV light, leading to inflammation and damage to the skin. These substances can be ingested medications, topical medications, or even natural compounds found in plants.

When a phototoxic substance is present on or in the skin, UV light can cause it to undergo a chemical change. This altered substance can then absorb energy from the UV light and transfer it to surrounding skin cells, initiating a cascade of inflammatory responses. The reaction is typically dose-dependent, meaning that the severity of the reaction is related to the amount of substance present and the intensity and duration of UV exposure.

Symptoms of fototoxicitet usually appear within minutes to hours after UV exposure and can range from mild redness and itching to severe blistering and swelling. The affected areas are typically those exposed to sunlight. Common culprits include certain antibiotics, diuretics, nonsteroidal anti-inflammatory drugs (NSAIDs), and some topical retinoids. Certain plants, like those in the citrus family or wild parsnip, can also cause phototoxic reactions upon skin contact followed by sun exposure.

Prevention involves avoiding known phototoxic agents and protecting the skin from UV radiation through the use of sunscreen, protective clothing, and limiting sun exposure during peak hours. If a phototoxic reaction occurs, avoiding further UV exposure and treating the symptoms with cool compresses and topical anti-inflammatories is usually recommended.