phytophotodermatitisa

Phytophotodermatitis is a skin reaction that occurs when certain plant compounds come into contact with the skin and are then exposed to ultraviolet (UV) light. These plant compounds are known as furocoumarins. When furocoumarins are absorbed by the skin and subsequently exposed to UV radiation, they can cause inflammation and damage to skin cells.

The most common culprits are plants belonging to the Apiaceae (formerly Umbelliferae) family, such as parsley, celery, carrots, and parsnips, as well as the Rutaceae family, which includes citrus fruits like limes, lemons, and grapefruits. Other plants, like fig trees and wild parsnip, can also trigger the reaction.

Symptoms typically appear as redness, swelling, and blistering on the skin. This is often followed by hyperpigmentation, where the affected areas become darker than the surrounding skin. The rash usually develops within 24 to 48 hours after exposure and can last for several days to weeks. The severity of the reaction can vary depending on the concentration of furocoumarins, the duration of sun exposure, and individual skin sensitivity.

Diagnosis is usually made based on the characteristic rash pattern, the history of contact with relevant plants, and subsequent sun exposure. Treatment generally involves avoiding further exposure to the offending plants and sunlight. Cool compresses, topical corticosteroids, and moisturizing lotions can help alleviate symptoms. In severe cases, oral medications may be prescribed. Prevention primarily involves wearing protective clothing and washing the skin thoroughly after handling potentially irritating plants, especially before going into the sun.