poison ivy dermatitis


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Related to poison ivy dermatitis: Rhus dermatitis, contact dermatitis, urticaria

poison ivy dermatitis

Etymology: L, potio, drink; ME, ivi + Gk, derma, skin, itis, inflammation
an allergic contact dermatitis caused by exposure to a nonvolatile oil, toxicodendrol, present in the leaves and other plant parts of poison ivy, a member of the Rhus toxicodendron species. Other Rhus species producing the same kind of contact dermatitis are poison oak and poison sumac. Also called rhus dermatitis.
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Poison ivy dermatitis

poison ivy dermatitis

Dermatitis resulting from irritation or sensitization of the skin by urushiol, the toxic resin of plants of the genus Toxicodendron (Rhus). There is no absolute immunity; susceptibility varies greatly, even in the same individual.

Those sensitive to poison ivy may also react to contact with other plants, such as the mango rind and cashew oil. These plants contain chemicals that cross-react with the sap present in poison ivy, poison oak, and poison sumac.

Symptoms

Some time elapses between skin contact with the poison and first appearance of symptoms, varying from a few hours to several days and depending on the sensitivity of the patient and the condition of the skin. Moderate itching or a burning sensation is soon followed by small blisters; later manifestations vary. Blisters usually rupture and are followed by oozing of serum and subsequent crusting.

Prevention

Some barrier creams have been used to prevent poison ivy dermatitis. They are sprayed on the skin prior to anticipated contact with the plant.

Treatment

In mild dermatitis, antihistamines and a lotion to relieve itching are usually sufficient. In severe dermatitis, cool, wet dressings or compresses, potassium permanganate baths, and topical corticosteroids are often effective. In some instances intramuscular or oral corticosteroid therapy is used. If plant leaves are burned and the smoke inhaled, or if plant leaves are ingested, the patient should be directed to an emergency care center. Demulcents, fluids, morphine, and a high-protein, low-fat diet may be prescribed.

Patient care

Prevention is important in those with known sensitivity and in those with no previous contact with or reaction to the plant. Instruction of the patient focuses on helping the patient to recognize the plant, to avoid contact with it, and to wear long-sleeved shirts and long pants in wooded areas. If contact occurs, the patient should wash with soap and water immediately to remove the toxic oil. Contaminated clothing and pets also should be promptly and thoroughly washed because contact with such items may cause poison dermatitis in other members of the household.

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See also: dermatitis