fotodermatát

Fotodermatitis is a skin reaction that occurs when the skin is exposed to sunlight, and then a particular substance comes into contact with the skin, or is present in the body. This reaction can be triggered by a wide range of substances, including certain medications, cosmetics, fragrances, and even some plants.

There are two main types of fotodermatitis: photoallergic and phototoxic. Phototoxic reactions are more common. They occur when a substance absorbs UV radiation and then releases energy that damages skin cells, causing a sunburn-like reaction. This reaction typically appears within minutes to hours after sun exposure and may resemble a severe sunburn with redness, itching, and sometimes blistering.

Photoallergic reactions are less common and are true allergic reactions. They occur when UV radiation alters a substance, making it recognizable to the immune system as foreign. The immune system then mounts an allergic response, which can result in an itchy, eczematous rash that may spread beyond the sun-exposed areas. This reaction usually takes 24 to 72 hours to develop after sun exposure.

Identifying the causative agent is crucial for managing fotodermatitis. This often involves a thorough medical history, a review of medications and products used, and sometimes patch testing or phototesting. Treatment focuses on avoiding the trigger substance and protecting the skin from further sun exposure. Sunscreens with high SPF and broad-spectrum protection are recommended. In some cases, topical or oral corticosteroids may be prescribed to alleviate inflammation and itching.