Phytophotodermatitis: A Form of Plant Dermatitis

Introduction

Phytophotodermatitis (PPD) is a cutaneous phototoxic inflammatory eruption that results from contact with light-sensitizing botanical substances that are known as furanocoumarins. Furanocoumarins is a long-wave ultraviolet A (UV-A, 320-380 nm) radiation, and Psoralen is an active particle in furanocoumarins. Furanocoumarins are found in certain plants (e.g., celery, parsley, limes, carrots). The skin reaction is elicited in the person exposed to an adequate amount of ultraviolet rags and photosensitizer. They react using their active particle psoralen along with UV radiation, which forms the eruption of the skin. The skin eruption usually occurs after 24 hours of exposure, and it peaks at 48 to 72 hours after exposure.

What Is Phytophotodermatitis?

Phytophotodermatitis gets its name from the Greek term “phyto” known as plant, “photo” meaning light, and dermatitis refers to inflammation of the skin. It is also known as berloque dermatitis or margarita photodermatitis. Phytophotodermatitis manifests as burning erythema that may eventually form into a blister. Postinflammatory hyperpigmentation lasts for weeks to months. The inflammatory reaction can be mild and can go unrecognized by the patient. The pain may be associated with the blister, which can result in necrosis of the affected epidermis. The rash is usually nonpruritic. The plants associated with phytophotodermatitis have four plant families. They are the carrot family (Apiaceae), the mulberry family (Moraceae), the citrus family (Rutaceae), and the legume family (Fabaceae).

Phytophotodermatitis also has a subtype which is known as berloque dermatitis. Berloque dermatitis is caused by a substance found in the perfume. The symptoms of berloque dermatitis include streak marks where the perfume is applied, especially around the wrist and neck. In addition, berloque dermatitis is caused by the substance known as bergapten. Therefore, one needs to avoid this substance if they have sensitive skin.

What Are the Causes of Phytophotodermatitis?

Phytophotodermatitis is not an immunologic response, as no prior exposure to the photosensitizing agent is required. Phytophotodermatitis occurs by exposure to furocoumarins, a chemical found on the surfaces of the plant. With the process of photosynthesis, the chemical becomes activated by UVA rays. These activated substances can cause skin reactions in some people, and phytophotodermatitis affects the epidermis - the outer layer of the skin. The plants that may cause phytophotodermatitis include

• Celery.

• Carrots.

• Wild dill.

• Citrus fruits.

• Figs.

• Wild parsnips.

• Wild parsley.

The initial blisters occur from the chemicals as it affects the epidermis. Excess melanin in the skin cells is caused by furocoumarins, which cause subsequent discoloration of the skin.

What Are the Symptoms of Phytophotodermatitis?

The symptoms of phytophotodermatitis usually begin after 24 hours of exposure. The symptoms can be mild, moderate, or severe and include

• Itching.

• Pain.

• Inflammation.

• Tenderness.

• A large area of blistering.

• Burning sensation.

• Irregular, crusted patches on the skin.

• Redness of the skin.

• Discoloration of the skin.

What Are the Risk Factors for Phytophotodermatitis?

Everyone does not experience phytophotodermatitis after they are exposed to furocoumarins. However, people with a history of contact dermatitis are at higher risk of developing this. Other risk factors responsible for the skin reaction include

• Gardening.

• Playing outdoors or working.

• Outdoor activities in wooded areas.

• Touching plants with a lot of sap.

• Touching plants, especially during the midday when UVA (ultraviolet A) levels are high.

• Bartending or cooking.

• Campfires.

• Accidental exposure from using furocoumarins containing wood.

Some people are at risk of developing phytophotodermatitis, including

• Canners.

• Forest rangers.

• Farmers.

• Gardeners.

• Cooks and kitchen staff.

• Bartenders.

How Is Photodermatitis Diagnosed?

Phytophotodermatitis can be diagnosed by physical examination. Mild cases of phytophotodermatitis usually do not require a doctor’s visit. However, one can talk to their healthcare provider if they have moderate to severe itching or blistering. Generally, phytophotodermatitis is often confused with other skin conditions such as hives, sunburn, sun allergies, poison oak, poison ivy, etc.

What Is the Treatment for Phytophotodermatitis?

Phytophotodermatitis can primarily be treated with home care. Topical ointments like steroids can help cure inflammation, itching, and initial blisters. Mild to moderate blisters can be soothed with cold compresses. The topical medications do not help to cure the pigmentation changes that occur in later stages. Skin discoloration often fades with time. Reducing sun exposure can help in preventing skin discoloration. Other treatments like photochemotherapy are often used to treat skin diseases like psoriasis. Photochemotherapy and bleaching agents are not recommended in phytophotodermatitis. The treatment options include:

• Avoiding Other Skin Irritants: Wear cotton clothes. Avoid the use of harsh detergents, personal care products, and soaps.

• Avoiding Re-exposure: Avoid reexposure to the plants that caused the skin reaction, as the symptoms may reappear.

• Cold Compresses: Place a cool cloth on the affected area to provide relief.

• Topical Ointments: Apply soothing ointments, creams, and lotions to reduce the itching and swelling.

• OTC Medications: OTC (over-the-counter) medications include Ibuprofen and Aspirin, which help reduce pain and swelling.

• Steroid Creams: Steroid creams will help to reduce inflammation and itching.

• Reduce Sun Exposure: Spend less time in the sun, especially when the UV rays are strongest. This will help to prevent hyperpigmentation from becoming even darker. Also, wear sunscreen during sun exposure.

How to Prevent Phytophotodermatitis?

Preventive measures have proven to be most helpful in dealing with phytophotodermatitis. Some tips to prevent phytophotodermatitis include:

• Wear gloves while gardening.

• Wear long-sleeved clothing in wooded areas.

• Apply sunscreen before sun exposure to avoid an accidental rash.

• Wash hands and other exposed parts with soap and water immediately after coming home.

Conclusion

Phytophotodermatitis is usually not serious, and the complications are uncommon. The condition resolves on its own. Phytophotodermatitis occurs when certain plant chemicals cause inflammation of the skin when it is exposed to sunlight. Contact a dermatologist if anyone observes any skin changes when exposed to plant chemicals.