WILD PARSNIP

Wild parsnip is a plant that can cause serious skin reactions. It contains chemicals called psoralens, or furocoumarins, which can cause what dermatologists call phyto-photodermatitis. This is inflammation of the skin (dermatitis) triggered by a plant (phyto) and sunlight (photo). When these chemicals are absorbed by the skin, ultraviolet light—present on both sunny and cloudy days—energizes them, causing them to bind with DNA and cell membranes. This damages skin cells and tissue, although the reaction may take time before visible symptoms appear.

In mild cases, affected skin reddens and feels sunburned. In more severe cases, the skin reddens first, then blisters form—sometimes impressively large—and the area can feel scalded. Areas with more sensitive skin, such as the arms, legs, torso, face, and neck, are most vulnerable. Perspiration can increase absorption of the psoralens.

Blisters usually appear one to two days after sun exposure. After they rupture, the skin begins to heal. A signature effect of wild parsnip is dark red or brownish discoloration in the area of the burn. This hyperpigmentation can persist for up to two years.

Parsnip burns often appear as streaks or long marks, showing where a leaf or stem brushed across the skin while exposed to sunlight. Because the reaction can resemble poison ivy and wild parsnip is rarely accurately identified, it is often misdiagnosed and treated as poison ivy. Noting six clinical differences (see sidebar) can help distinguish the two.

TREATING A PARSNIP BURN

If you get a parsnip burn, relieving the symptoms should come first. Cover the affected area with a cool, wet cloth. If blisters are present, try to keep them from rupturing, as the skin of a blister acts as a natural bandage, protecting the underlying skin while it heals. If blisters do pop, try to leave the skin “bandage” in place. To prevent infection, keep the area clean and apply an antibiotic cream.

Adding Domeboro powder to cool cloth compresses can help dry weeping blisters. In cases of extreme discomfort, a doctor may recommend a topical or systemic cortisone-steroid. For serious burns with extensive blistering, consult a physician.

Avoiding exposure is the best strategy. Learn to recognize the plant in different seasons and growth stages so you can steer clear of it, or protect yourself by wearing gloves, long pants, and long-sleeve shirts. Some people pull wild parsnips in the evening when sunlight is minimal. If plant juice contacts your skin, wash the area thoroughly as soon as possible to reduce the severity of the reaction.