poison ivy, poison oak, and poison sumac dermatitis
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Alternative Names allergic contact dermatitis, poison oak dermatitis, poison plant dermatitis
Definition Exposure to poison ivy results in an allergic reaction of the skin to the plant oils from the poison ivy family of plants.
What is going on in the body? Not everyone is allergic to poison ivy. If poison ivy resin from the plant touches the skin of someone who is allergic, it starts a reaction that results in blisters. The outbreak of the reaction starts at the spot on the skin where the resin touched it. Once poison ivy oils have been washed off of the skin thoroughly and no further contact is made, no further spread of the poison ivy can occur. Original sites of contact may continue to sprout up with blisters over the course of several days after the time of original contact. Portions of the skin that had the greatest contact usually react first, followed by areas of skin that had less contact with the plant. This often gives people the impression that the dermatitis is contagious, which it is not. Fluid from broken blisters does not spread the dermatitis either.
What are the signs and symptoms of the condition? Symptoms include red welts and blisters in lines on exposed areas of skin, and burning and itching ranging from mild to severe.
What are the causes and risks of the condition? Skin contact with plant oils from the poison ivy family of plants can cause an allergic reaction.
What can be done to prevent the condition? To prevent an allergic reaction to the poison ivy plant, avoid contact with the poison ivy plant. Wear long sleeves and long pants, and wash both the skin and clothing thoroughly after any potential contact. People who are especially sensitive to poison ivy and who must go into areas where poison ivy or poison oak is common can apply a skin cream that protects them from the poison ivy.
How is the condition diagnosed? Often the person diagnoses poison ivy himself or herself by noticing the itchy blisters and recalling plant contact in areas where there was poison ivy or poison oak. Otherwise, the doctor makes the diagnosis by examining the rash and asking about possible poison ivy contact.
What are the long-term effects of the condition? There are usually no long-term effects from exposure to poison ivy. Repeated bouts of poison ivy can become more severe and particularly harmful when involving large areas of the skin surface or facial and oral skin.
What are the risks to others? Poison ivy reactions can only be spread to other individuals through skin-to-skin contact before the oils have been washed off. Special care needs to be taken when handling affected clothing, jewelry, shoes or animals that have come into contact with any part of the plant.
What are the treatments for the condition? Treatments range from home remedies to prescription medications.
Cool compresses soaked with tap water or baking soda water or Epsom salts can relieve some of the symptoms, at least temporarily.
Topical corticosteroids, such as hydrocortisone, are often recommended, but prescription strength creams or ointments, such as betamethasone or triamcinolone, may be needed in more severe cases.
Antihistamines, such as diphenhydramine, are often suggested to reduce itching, which if left uncontrolled can lead to inflammation and infection from scratching.
Oral corticosteroids, such as prednisone or methylprednisolone, may be utilized in severe cases.
What are the side effects of the treatments? Those side effects associated with use of oral corticosteroids may include mood disturbance, increased appetite, increased blood pressure, elevated blood sugar and bone or skin thinning.
What happens after treatment for the condition? Recuperation from poison ivy should occur in 1 to 2 weeks, although repeat occurrences occasionally happen with repeat exposure. Re-exposure to poison ivy oils may occur, for example, after handling camping gear, golf clubs, clothing, or pet fur that was originally exposed to the poison ivy.
How is the condition monitored?
Author: Lynn West, MD Reviewer: Eileen McLaughlin, RN, BSN Last Updated: 02/02/01 Contributors Potential conflict of interest information for reviewers available on request
