Poison Ivy, Oak, or Sumac: Other Plants That Cause a Rash

Topic Overview

Poison ivy, oak, and sumac are not the only plants that can cause rashes.

Rashes from urushiol

Some plants contain urushiol, the same oil found in poison ivy, oak, and sumac. Or they may contain a substance that is enough like to urushiol to cause a similar rash. Contact with these plants can make you allergic to urushiol. As a result, you will get a rash upon contact with poison ivy, oak, or sumac, even if you never had contact with it before. These plants include:

• Ginkgo trees.
• Japanese lacquer trees.
• Mangoes (the allergenic oil is in the fruit's rind and leaves).
• Cashews (the allergenic oil is in the shell).
• Indian marking nut trees.
• Tropical silk oaks (sometimes grown as ornamental houseplants).

Rashes from irritant plants

Irritant plants may cause a rash where they come into contact with the skin. Unlike with poison ivy, oak, or sumac, you do not have to be allergic to the plant to develop a rash. Irritant plants include:

• Flower bulbs, such as hyacinth or daffodil bulbs or tulip bulb sheaths. These can cause a reaction called daffodil itch or tulip fingers. Tulips can cause either an irritant reaction or an allergic reaction.
• Roses, rose hips, and dahlias.
• Stinging nettle and spurge nettle.
• Herbs such as comfrey, borage, barberry, tansy, yarrow, garlic, and hot peppers.
• Rhubarb.
• Plants of the bromeliad family, such as pineapple and Spanish moss.
• Cacti and sharp grasses.

Rashes from plants and sunlight

Certain plants have a chemical that sunlight converts into an allergen. Some people who touch these plants and then go into the sun have an immune system reaction similar to a poison ivy, oak, or sumac rash (allergic contact dermatitis). The rash only develops in areas exposed to sunlight. These plants include:

• Celery, parsley, parsnip, carrot, dill, and fennel.
• Citrus plants (bergamot, lemon, lime).
• Queen Anne's lace.
• Rue and angelica.
• Fig.