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The wild parsnip (Pastinaca sativa) is a tall plant with yellow flowers. Although the roots are edible, the plant’s sap can result in burns (phytophotodermatitis).

The burns are a reaction between the plant’s sap and your skin. The reaction is triggered by sunlight. It isn’t an immune or allergic response, but rather a sun-sensitive skin reaction due to the plant substance.

Learn more about wild parsnip burns, including symptoms, treatment, and prevention.

Phytophotodermatitis is a skin reaction caused by a substance found in many plants, including wild parsnip. This substance is called furanocoumarin, or furocoumarins.

Furanocoumarin causes your skin to be extra sensitive to ultraviolet (UV) light. When the sap from the leaves and stems of these plants gets on your skin, and your skin is then exposed to sunlight, an inflammatory reaction takes place.

Other plants that may cause phytophotodermatitis

  • carrot
  • celery
  • fennel
  • fig
  • giant hogweed
  • lime
  • mustard
  • wild dill
  • wild parsley

About 24 hours after getting wild parsnip sap on your skin and being exposed to sunlight, you’ll begin to experience symptoms.

Symptoms start with an intense local burning sensation, followed by a red rash. Over the next couple of days, the rash may get worse — sometimes with severe blistering.

Some people may not recall any redness or blistering. Instead, you may see irregular patches on the skin, sometimes as linear streaks, a random cluster of small spots, or even fingerprint-sized spots.

After about 3 days, the symptoms start to get better. Eventually, like after a bad sunburn, the burned skin cells die and flake off.

As symptoms improve, the rash may appear lighter or darker. Discoloration and sensitivity to sunlight in the affected areas can remain for up to 2 years.

Wild parsnip burns will resolve on their own with time. It’s important to keep the affected area from being exposed to sunlight to avoid further burning and prevent further discoloration. Sunscreen is essential to prevent dark spots from darkening in the sun.

If contact with wild parsnip sap followed by exposure to sunlight causes a burn and blisters, you can try ice packs for pain relief.

If needed, try an over-the-counter (OTC) hydrocortisone cream to help soothe the inflammation. You might also consider using ibuprofen or acetaminophen for pain relief.

If the burn and blistering is severe, see a doctor. They may recommend a systemic or more potent prescription topical steroid to help relieve your discomfort.

Your skin will typically heal without an infection. Get immediate medical care if you see the signs of infection, such as:

  • fever of 100.4°F (38°C) or higher
  • increasing swelling or redness
  • pus coming from the affected area

Wild parsnip will grow up to about 4 feet tall, and it’ll look and smell much like a cultivated parsnip. The stem is hollow, with vertical grooves running its full length. The stem and its multi-toothed leaves are a yellowish-green color. It has flat-topped flower clusters with yellow petals.

If you live in an area that has wild parsnip, you might come across it when hiking or harvesting crops, including u-pick operations.

To avoid, or at least reduce the risk of exposure to wild parsnip sap, wear full-coverage shoes, long pants, and long-sleeved shirts when involved in outdoor activities.

Wild parsnip is common throughout the northern United States and southern Canada, ranging from Vermont to California and south to Louisiana. Wild parsnip isn’t found in:

  • Alabama
  • Florida
  • Georgia
  • Hawaii
  • Mississippi

If your skin has come in contact with sap from a wild parsnip, immediately cover the affected area. Your goal is to shield your skin from sunlight to prevent a reaction.

Once inside and out of the sun, wash the contact area with mild soap and warm water. Even after washing, the area might be sensitive for about 8 hours and must be kept out of the sun and away from UV light for that period.

Wild parsnip is a plant with furanocoumarin within it. When your skin comes in contact with the sap from the wild parsnip, the furanocoumarin makes it extra sensitive to UV light.

If your skin is then exposed to sunlight, an inflammatory reaction (phytophotodermatitis) takes place. This results in a painful, burning, and blistering rash that usually results in dark spots on the skin afterward.