Overview

Phytophotodermatitis is a type of contact dermatitis. It can be easier to understand by breaking its name down into three parts:

  • phyto, which means plant
  • photo, which means sunlight
  • dermatitis, which is inflammation of the skin

In this condition, contact with certain plant chemicals can cause skin inflammation when exposed to sunlight. It’s less common than other types of contact dermatitis.

The symptoms of phytophotodermatitis can be worrisome, but the condition usually goes away on its own over time. More serious cases may be treated by a dermatologist.

Symptoms of phytophotodermatitis

The symptoms of phytophotodermatitis vary based on the cycle of the reaction. At first, you may experience blister-like patches across the skin. These are often itchy and irregularly shaped. These patches appear wherever your skin is exposed to the plant substance. The most commonly affected areas are the:

  • legs
  • hands
  • arms

Aside from round blisters, the patches can also appear in the form of drips and streaks.

The blisters don’t itch as much after the initial reaction. The redness and inflammation (swelling) also goes down. However, you may find dark pigmentation in place of the blisters. This is called post-inflammatory pigmentation. This stage can last for several weeks, or even months.

Pictures of phytophotodermatitis

What are the causes?

Phytophotodermatitis is caused by exposure to furocoumarins. This is a type of chemical found on plant surfaces. The chemical can become activated by UVA rays through the process of photosynthesis. If your skin comes into contact with the chemical and the chemical becomes activated, a reaction can occur. Contact with this activated substance, even briefly, can cause skin reactions in some people. Phytophotodermatitis affects the epidermis only. The epidermis is the outer layer of the skin.

Some plants that may cause phytophotodermatitis include:

  • carrots
  • celery
  • citrus fruits (most commonly limes)
  • figs
  • wild dill
  • wild parsley
  • wild parsnips

The initial blistering symptoms are caused by the effects of the chemical on the epidermis. Furocoumarins are also responsible for producing excess melanin in skin cells. This causes the subsequent discoloration of the skin.

Berloque dermatitis

Phytophotodermatitis also has a subtype called berloque dermatitis. This is caused by certain substances found in perfume. Symptoms include streak marks where you apply perfume — most often around the neck and wrists.

Berloque dermatitis is caused by a substance called bergapten, which may cause these reactions in high quantities. Though the condition is rare, you might consider avoiding this substance if you have sensitive skin.

Risk factors for phytophotodermatitis

Not everyone will experience phytophotodermatitis after exposure to furocoumarins. You may be at a greater risk if you have a history of contact dermatitis with other substances, such as metals and cleaning agents.

Other risk factors for this skin reaction may include:

  • working or playing outdoors
  • gardening
  • walking or other activities in wooded areas
  • contacting plants during midday when UVA levels are higher
  • coming into contact with plants at higher altitude
  • touching plants that have a lot of sap
  • campfires, which can lead to accidental exposure from using furocoumarin-containing wood
  • cooking or bartending

Phytophotodermatitis is also more prevalent in the spring and summer. This is when plants are generally most active in producing substances that might be toxic to human skin. Also, you may be more likely to go outside during these warmer months and come into contact with plants.

It’s possible to spread phytophotodermatitis before furocoumarins are exposed to UVA rays. This is especially the case between parent and child. In fact, some cases of the condition in children are incorrectly mistaken for child abuse.

Diagnosing phytophotodermatitis

Mild cases of phytophotodermatitis don’t necessarily require a doctor’s visit. Talk to your primary care provider or dermatologist if you have severe blistering and itching. You’ll also need to see a doctor if you notice signs of infection, such as oozing sores.

Phytophotodermatitis is often confused with other skin conditions, such as:

Your doctor can diagnose phytophotodermatitis with a physical exam. They will look at your symptoms and ask you about recent activities you’ve participated in and when the symptoms started.

What are the treatment options?

Phytophotodermatitis is primarily treated with home care. Moderate blistering may be soothed with cool washcloths. Topical ointments, such as steroids, can help the initial blisters and inflammation in more severe outbreaks. In turn, these also help alleviate itchiness.

Read more: Contact dermatitis treatments »

Steroids and other topical medications don’t help the pigmentation changes that occur in the second stage. The best treatment measure for post-inflammatory pigmentation is time. Skin discoloration will often fade on its own over the course of several weeks. Reducing sun exposure can also help prevent the discoloration from darkening even further.

Photochemotherapy, often used in other skin diseases like psoriasis, is not recommended for this condition because it can worsen pigmentation changes. Bleaching agents have also proven to be ineffective.

Preventive measures prove to be most helpful in dealing with phytophotodermatitis. Basic soap and water goes a long way in removing the chemicals that cause this skin reaction.

Prevention tips

  • Wash your hands and other exposed parts of the skin immediately after being outdoors.
  • Wear gloves when gardening.
  • Wear pants and long sleeves in wooded areas.
  • Put on sunscreen before heading outdoors to prevent an accidental rash from exposed hands.

Outlook

Phytophotodermatitis isn’t a serious condition, but its effects can last for several weeks or even months. This condition doesn’t require medical treatment except for cases in which your symptoms are severe. Over time, phytophotodermatitis clears up on its own.

Recurring cases of phytophotodermatitis aren’t common. Once you get the condition, you’re more likely to take care in the outdoors and avoid certain plants and fruits to prevent future exposure. See your doctor if you have a rash that isn’t getting better or is getting worse so that they can rule out the possibility of another type of skin condition.