Valoherkistymisiä

Valoherkistymisiä, commonly known as photosensitivity or phototoxicity, refers to an exaggerated response of the skin to ultraviolet (UV) radiation from the sun or artificial sources like tanning beds. This heightened sensitivity can manifest in several ways, often involving skin reactions that are more severe or occur more readily than in individuals without photosensitivity.

There are two main categories of photosensitivity reactions. The first is photodermatoses, which are skin conditions that are either caused or exacerbated by UV light. Examples include polymorphic light eruption, solar urticaria, and chronic actinic dermatitis. These conditions often involve an immune system response to UV exposure. The second category is phototoxic drug reactions. This occurs when a medication or substance taken internally or applied topically is activated by UV light, leading to skin damage that resembles an exaggerated sunburn. Common culprits include certain antibiotics, diuretics, and nonsteroidal anti-inflammatory drugs.

Symptoms of photosensitivity can vary widely and may include redness, itching, burning, blistering, and rash. The severity and type of reaction depend on the underlying cause, the individual's sensitivity, and the amount of UV exposure. Diagnosis typically involves a medical history, physical examination, and sometimes phototesting to determine the specific wavelength of light that triggers the reaction. Management strategies focus on avoiding UV exposure through sun protection measures like sunscreen, protective clothing, and seeking shade.