By Shawn Eck, PA-C
Reliant Medical Group Dermatology

Although it’s not commonly known, certain plant compounds when combined with exposure to the sun can cause a severe skin reaction. Known as phytophotodermatitis, this condition can sometimes result in quite a painful rash, including blisters. Phytophotodermatitis usually occurs without you being aware of it. For instance, if you are cutting lemons and then receive sun exposure without washing your hands. It’s important to be aware of phytophotodermatitis as it has been known to be misdiagnosed and mistaken for other skin problems.

Some of the plants that can cause phytophotodermatitis are:

• Citrus fruits and juices (limes, lemons, grapefruits, oranges)
• Celery
• Carrots
• Wild parsnips
• Meadow grass
• Dill
• Fig leaves
• Fennel
• Saint-John’s-wort
• Hogweed (as well as other plants)

The plant chemicals known for causing this condition are called furocoumarins. Plants produce furocoumarins as a way to help protect themselves from harmful fungi and insects. While protective to the plant, these same compounds can cause problems when we get them on our skin and then receive ultraviolet light from the sun.

Phytophotodermatitis can be identified by patches of redness and/or blisters that are often irregularly shaped since they represent the areas of the skin that were exposed to the plant. Indirect contact, such as touching your skin with your hands, can also cause phytophotodermatitis.

Here are some key things to know about phytophotodermatitis:

• Symptoms usually begin 24 hours after exposure
• The symptoms can be mild or severe and include patches of redness and/or blisters
• The inflammation can cause pain, tenderness, and itching and as well as a burning sensation
• Wet skin, including sweat and heat, can worsen the symptoms
• Avoiding the sun can help prevent phytophotodermatitis

Phytophotodermatitis can have long-lasting effects. After the initial symptoms subside after about 7-14 days the skin can show signs of darkening, which is known as hyperpigmentation. This problem can last for weeks or even months. This hyperpigmentation can occur even in mild cases of phytophotodermatitis.

Most often, mild cases of phytophotodermatitis do not usually require medical care. However, if symptoms persist or are severe, you should contact your doctor. Treatment is similar to treatment of poison ivy and can include prescription medication in some cases. A cold compress applied to the skin is a good way to provide relief. Keep the area well-lubricated with Vaseline or another ointment, especially if you have blisters. Washing your hands often while working with fruits and plants that can cause phytophotodermatitis and limiting time in the sun is a good way to prevent this painful problem.