Skin: The Hidden Danger from Plants and the Sun

The next time you want to enjoy a cocktail by the pool or have a picnic at the beach, you should not only be careful not to stay in the water for too long. You also need to make sure that your skin has not been exposed to substances that can increase its sensitivity to the sun. Otherwise, you risk developing phytophotodermatitis.

Phytophotodermatitis develops when certain substances in plant-based foods interact with the sun’s ultraviolet radiation, causing inflammation and characteristic skin lesions. A classic example of phytophotodermatitis is the rash often observed in people who grill meat over charcoal and pour lemon juice on it.

“Any activity that involves squeezing citrus fruits and then sun exposure can cause skin changes in individuals predisposed to them,” says Dr. Markos Michelakis, Dermatologist-Aphrodisiologist (Aesthetic Dermatology-Dermatosurgery). “However, phytophotodermatitis does not only occur after exposure to lemons, limes, citrons, or oranges. Many plants and plant-based foods contain natural substances that can increase sensitivity to the sun (photosensitizers).”

One of these substances is psoralen, which is found in citrus fruits and many other plants and plant-based foods, such as parsnip, parsley, carrots, celery, figs, savory (an aromatic plant), and various grasses. Psoralen may also be present in certain fragrances and plant oils, such as bergamot oil.

“When psoralen is exposed to UVA radiation, it triggers photochemical reactions in the skin. These reactions damage skin cells and lead to their destruction, resulting in the appearance of characteristic symptoms,” explains Dr. Michelakis.

These symptoms usually begin within 24 hours of exposure and peak at 48-72 hours. They can range from mild to severe. The affected person may develop blisters on the skin, complain of itching and a burning sensation, and exhibit inflammation, redness, pain, and tenderness. After the blisters rupture, they may form a crust.

“Blisters usually have an irregular shape, depending on the amount of photosensitizer the skin was exposed to,” the specialist clarifies. “For example, if lime juice dripped on a few spots on the hand, drop-shaped blisters may appear. If the juice of a whole lemon falls, a large blister may form. And if the skin rubs against a plant, blisters may appear in streaks.”

Once the initial symptoms subside (usually 7-14 days), the skin may appear darker. This is due to hyperpigmentation observed after phytophotodermatitis, which can last for several weeks or months.

However, some people may develop very mild inflammation, without blisters or other visible skin lesions. In such cases, hyperpigmentation may be the first indication that they have experienced phytophotodermatitis.

Sweating, heat, and the presence of water on the skin generally worsen the initial symptoms. Continued sun exposure can intensify hyperpigmentation and make the skin appear even darker.

Phytophotodermatitis can occur in people of all ages, genders, and races. However, certain factors increase the risk of developing it. These factors include the use of perfumes or oils containing certain plant components, exposure to intense sunlight, and participation in certain activities. Examples of high-risk activities include camping, outdoor cooking, fishing, hiking, gardening, outdoor games, and sports.

Certain professionals are also at increased risk of phytophotodermatitis. These include farmers, gardeners, agronomists, forest rangers, kitchen staff (e.g., chefs, waiters, assistants), especially when working outdoors, bartenders, and others.

The diagnosis of phytophotodermatitis is based on a detailed history and characteristic lesions. However, it often resembles other skin conditions, such as atopic dermatitis, cellulitis, fungal infections, severe sunburn, chemical burns, etc. Therefore, the doctor may request additional tests, such as specialized skin tests or even a skin biopsy.

Mild cases usually resolve without specific treatment, other than protection from the sun and avoidance of any substances that may trigger skin sensitivity.

More severe cases may require additional measures, such as cold compresses, which can help soothe the patient’s symptoms. The dermatologist may also recommend soothing ointments, lotions, or creams, and even medication (e.g., topical or systemic corticosteroids, pain relievers, antihistamines).

Although phytophotodermatitis is usually mild to moderate, severe cases can occur. It may also affect a large portion of the skin. In the most severe cases with extensive lesions, hospitalization may even be necessary.

“Proper management is important because there is a risk of complications, such as infections when blisters rupture,” emphasizes Dr. Michelakis. “However, prevention is always the best treatment: everyone should wash their hands thoroughly when handling any plant-based food or plant. Even better, wear gloves if you will be exposed to the sun afterward.”

https://www.medicalnewstoday.com/articles/319001

https://health.clevelandclinic.org/lime-juice-and-sunshine-can-make-for-painful-unexpected-sunburn/

https://dermnetnz.org/topics/phytophotodermatitis/

https://health.clevelandclinic.org/lime-juice-and-sunshine-can-make-for-painful-unexpected-sunburn/