Poison ivy rash is a skin rash caused by an allergic reaction to urushiol, an oily resin found in poison ivy, poison oak, and poison sumac plants. It is not contagious, but the urushiol oil can remain on objects and spread the rash.
Symptoms
The most common symptom of poison ivy rash is an itchy, red rash that appears within 12 to 48 hours of exposure to urushiol. The rash may appear as:
- Red bumps
- Blisters
- Streaks or patches of skin
The rash can be mild or severe, depending on the amount of exposure to urushiol and the person’s sensitivity to it. In severe cases, the rash can cause fever, swollen lymph nodes, and headache.
Causes
Poison ivy rash is caused by an allergic reaction to urushiol, an oily resin found in poison ivy, poison oak, and poison sumac plants. Urushiol is very sticky and can easily attach to skin, clothing, pets, and other objects. Even a small amount of urushiol can cause a rash.
How to prevent poison ivy rash
The best way to prevent poison ivy rash is to avoid contact with poison ivy, poison oak, and poison sumac plants. If you must be in an area where these plants are present, wear long sleeves, long pants, and gloves. You can also apply a barrier cream to your skin before going outdoors.
If you come into contact with urushiol, wash your skin with soap and water as soon as possible. You may also want to wash your clothes and any other objects that may have come into contact with the oil.
Treatment
There is no cure for poison ivy rash, but there are treatments that can help relieve the symptoms. These include:
- Over-the-counter creams and lotions, such as calamine lotion or hydrocortisone cream
- Oral antihistamines, such as Benadryl or Claritin
- Cool compresses
In severe cases, your doctor may prescribe stronger medications, such as corticosteroids or antibiotics.
When to see a doctor
You should see a doctor if your poison ivy rash is severe or if you have any of the following symptoms:
- Fever
- Swollen lymph nodes
- Headache
- Large blisters
- The rash is spreading rapidly
With proper care, most poison ivy rashes will clear up within a few weeks.