Phototoxic contact dermatitis is a type of skin inflammation or irritation that occurs as a result of exposure to certain substances, combined with exposure to ultraviolet (UV) radiation. This condition is commonly characterized by the development of a rash or redness on the skin, which can be accompanied by itching, burning, or swelling.
The term "phototoxic" refers to the interaction between a substance and sunlight, specifically UV radiation, that triggers a reaction on the skin. The condition arises when a person's skin comes into contact with a specific substance, such as certain plants, chemicals, or medications, and is subsequently exposed to UV light. This exposure activates a process in which the substance becomes harmful to the skin, leading to the development of dermatitis.
Phototoxic contact dermatitis is different from allergic contact dermatitis, which occurs when the immune system reacts to an allergenic substance upon contact with the skin. Rather, in phototoxic contact dermatitis, the reaction is triggered by the combination of the substances with UV light.
Common substances that can cause phototoxic contact dermatitis include certain plants like giant hogweed or wild parsnip, fragrance or essential oils, coal tar derivatives, certain medications like antibiotics or nonsteroidal anti-inflammatory drugs (NSAIDs), and certain dyes or chemicals used in textiles or cosmetics.
Prevention of phototoxic contact dermatitis involves avoiding direct skin contact with the irritant substances and minimizing exposure to sunlight or other UV sources. Treatment usually involves soothing the irritated skin with topical corticosteroids, moisturizers, and avoiding activities that further aggravate the affected area. If needed, oral antihistamines can help alleviate itching and discomfort.
