What You Should Know About Phytophotodermatitis

Medically Reviewed by Zilpah Sheikh, MD on April 24, 2024
Written by Rita Colorito
6 min read

Poison ivy isn’t the only type of rash that’s linked with touching certain plants. Phytophotodermatitis may not feel as itchy, but it may feel a lot more painful. Here’s what you should know about it.  

Phytophotodermatitis (PPD) is an inflammatory skin reaction to chemicals in certain plants or fruits triggered by sunlight exposure. It’s a type of contact dermatitis — a rash that appears after contact with an irritant or allergen. In the case of phytophotodermatitis, it’s a skin rash that happens after you come into contact with furanocoumarins, a class of chemicals found in many plants.

Here’s the phytophoto part: Following skin contact, a substance in furanocoumarins called psoralen gets absorbed into your skin and reacts with UVA light exposure, causing an intense skin reaction. To recap: First your skin touches certain plants or fruits. Then the psoralen gets absorbed into your skin. When that skin is also exposed to UVA light — sunlight — the rash is triggered. 

Unlike other types of rashes, phytophotodermatitis is not an immune system response. And it’s usually not itchy. 

How common is it? 

PPD is most common in the spring and summer. This is when psoralen concentration in plants is the highest. It’s also when many people spend more time outdoors, often in the sun.  

You can get phytophotodermatitis if your skin absorbs psoralen from certain plants, fruits, or vegetables and is then exposed to UVA light. 

Plants that cause phytophotodermatitis 

Citrus fruits, especially lemons and limes, are one of the most common causes of phytophotodermatitis. Other plants that are linked to phytophotodermatitis include:

  • Bergamot
  • Buttercup
  • Capsaicin (peppers)
  • Celery
  • Carrots
  • Dill
  • Fennel
  • Fig
  • Hogweed
  • Mangos
  • Mustard
  • Parsley
  • Parsnip

Who gets phytophotodermatitis? 

Anyone can develop phytophotodermatitis, but some people are more at risk than others. Some may have jobs or hobbies that expose them to culprit plants and sun at the same time. These include: 

  • Arborists, farmers, gardeners, and forestry workers.
  • Hikers. Several case studies on phytophotodermatitis are of hikers who developed the painful skin rash during vacations in tropical locations.
  • Bartenders. Alcoholic drinks often include many of the triggering fruits and plants, especially citrus fruits. Bartenders who work outdoors and handle these ingredients often get what’s called “margarita burn,” since limes are often the biggest trigger.  
  • Kids, since they play outdoors.

Even though it’s a toxic reaction between the skin and the sun, phytophotodermatitis rash is not a sunburn. The severe chemical reaction in phytophotodermatitis kills skin cells and injures the skin. Only the skin exposed to the sun will develop a rash. 

What’s more, you may not notice the skin damage right away. It typically takes 24 to 48 hours after exposure to see a skin reaction. Skin changes can peak 3 to 4 days later. 

Symptoms of phytophotodermatitis rash are often quite painful and include:

  • Blistering, sometimes severe
  • Rash that appears in a splash or streaking pattern
  • Peeling skin
  • Mild redness that can last for weeks or months
  • Swollen skin
  • Rash along the upper lip, from drinks with citrus juice
  • Post-inflammatory hyperpigmentation, which can cause long-lasting skin discoloration. People with darker skin are more at risk. 

It can take several weeks for your skin to begin to heal. If you have darker skin, you may have skin discoloration during the healing process. 

Phytophotodermatitis is typically not an itchy rash. Your skin may start to feel a bit itchy as it heals and the damaged skin begins to peel off. 

To make a phytophotodermatitis diagnosis, a dermatologist will look at your skin and take a medical history. If you know you’ve been in contact with plants or produce containing furanocoumarins, let them know. 

Phytophotodermatitis is still not widely recognized by health professionals. The more information about your exposure and symptoms you can provide, the sooner you can get the right treatment for your phytophotodermatitis.

There is no cure for phytophotodermatitis. With time, the chemical reaction will go away. 

Phytophotodermatitis treatment consists of managing symptoms, such as pain or blisters. Treatments include:

  • Over-the-counter cortisone cream for mild cases
  • Over-the-counter nonsteroidal anti-inflammatory medications (NSAIDs) for pain
  • Prescription topical steroid creams to reduce inflammation
  • Wound care for blistered skin 

Severely blistered skin can cause open wounds in your skin. In some cases, you can develop a secondary skin infection. To prevent a skin infection, follow these steps from the American Academy of Dermatology Association:

  • Wash the wound with warm water and soap.
  • Dry the skin.
  • Apply an antibiotic ointment.
  • Cover the wound with a bandage.
  • Clean the wound and change the bandage daily until the wound heals.

If you develop complications of phytophotodermatitis, such as secondary infections, scarring, or significant changes in skin pigmentation, or if your symptoms persist, you should see a dermatologist. Complications may necessitate additional treatment to promote healing.

The best way to prevent phytophotodermatitis is to avoid direct skin contact with the plants and produce listed above when your skin is also exposed to UVA rays. If you work outdoors, wear gloves and long sleeve shirts and long pants to avoid direct skin-to-plant contact and sun exposure that can trigger phytophotodermatitis. 

If you come into contact with these plants while outdoors, wash the affected skin right away. It takes between 30 to 120 minutes before psoralen is absorbed into your skin. If you can wash it off before it has time to absorb, you can prevent the chemical reaction to the sun.

If you have cancer, you may need to pay even more attention to prevention. That’s because certain cancer medications increase photosensitivity, so it can take less sunlight to trigger a toxic reaction.

Follow these other tips to prevent phytophotodermatitis:

  • Avoid hand lotion and sanitizers with citrus oils or other plant culprits.
  • Don’t squeeze citrus fruits outdoors.
  • Follow basic sun safety: Wear sunscreen with at least SPF 30. Reapply often. Wear long sleeve shirts and long pants, especially when farming, gardening, or hiking. 
  • Know whether medications you take increase photosensitivity. Medications that can increase photosensitivity include certain cancer drugs, antibiotics such as doxycycline, antifungals such as voriconazole and griseofulvin, and diuretics such as furosemide and hydrochlorothiazide.
  • Wash your hands with soap and warm water after handling fruits, vegetables, and plants. 
  • Shower after farming, gardening, hiking, or playing in grassy areas outdoors. 

You should see a doctor or dermatologist if over-the-counter anti-inflammatory creams do not help or if you have a severe skin reaction. They can prescribe topical steroid creams or other medications to help your skin heal.

Phytophotodermatitis is a toxic skin reaction that happens when your skin comes into contact with certain plants and fruits and then is exposed to sunlight. Within 24 to 48 hours, the exposed skin will begin to break out into a streaked, blistered rash. It will take several weeks for the reaction to subside and for your skin to heal. Your doctor or dermatologist can prescribe topical steroids to help reduce inflammation and pain. 

  • How long does phytophotodermatitis last? It can take up to a week or more for your skin to start healing. It may take several weeks or months for redness and hyperpigmentation to go away. In some people, it can take several years for the skin discoloration to fade.
  • Does phytophotodermatitis scar? Phytophotodermatitis can cause long-lasting skin discoloration, especially in people with darker skin. In some cases, phytophotodermatitis can cause scarring, mainly if the reaction is severe or there is extensive blistering and damage to the tissues.
  • Is phytophotodermatitis permanent? Phytophotodermatitis eventually goes away. But it may take several weeks for your skin to heal. After your skin heals, it can remain hypersensitive. 
  • Is phytophotodermatitis a chemical burn? Phytophotodermatitis is a chemical reaction between psoralen absorbed in your skin and the sun’s UV rays.