Poison Ivy Dermatitis

Poison Ivy is the most common cause of allergic contact dermatitis in the US. It is due to a rash from the plant genus Toxicodendron, a type of plant in this genus is poison ivy. 


The rash is due to a hypersensitivity allergic reaction to a substance in the plant. 


Patients usually have redness and itching. They develop a rash which may have blebs, vesicles and may be in a linear pattern or streak like pattern to mimic the plants touch to the skin.


The diagnosis of Poison Ivy is made based on the symptoms, history and appearance of the rash. 


The treatment of poison ivy dermatitis depends on the symptoms. 

Oatmeal baths, calamine lotion, and cool, wet compresses may be soothing and help to decrease skin symptoms. 

Antihistamines may be an option if there is itching. 

Depending on the severity of the rash your doctor may prescribe topical or oral corticosteroids. 

If there is a superimposed bacterial infection antibiotics may be necessary. 


Prevention focuses on avoiding contact with the allergen. If there is a chance of contact gloves and protective clothing should be used. After possible exposure one should wash themselves with soap to minimize the risk of a rash.