Is Poison Ivy Contagious?

What Is Poison Ivy?

Poison ivy rash is not contagious. It is not transmitted from person-to-person. However, if there is still urushiol (the oil found in poison ivy that causes the rash) present on a person's skin or clothing, touching that oil may cause a rash.
Poison ivy rash is not contagious. It is not transmitted from person-to-person. However, if there is still urushiol (the oil found in poison ivy that causes the rash) present on a person’s skin or clothing, touching that oil may cause a rash.

Poison ivy is a plant usually found east of the Rocky Mountains, where it grows as vines or shrubs. Exposure to poison ivy can cause allergic contact dermatitis.

The leaves may have either smooth or notched edges and poison ivy is often identified by three leaflets with flowering branches coming from a single stem. The phrase, "leaves of three, let them be" can serve as a useful reminder to identify and avoid poison ivy and other related toxic plants. Characteristic black dots may also be present on the plant, which are oxidized urushiol (the oil that causes the reaction to poison ivy plants). Poison ivy plants can have different appearances based on the season, growth cycle, region, and climate.

What Are Symptoms of Poison Ivy?

Symptoms of poison ivy exposure include a red rash, which:

  • Appears within 4 hours to 4 days after exposure to the plant
  • Usually begins as small red bumps, and later develops into blisters that can vary in size 
  • May crust or ooze
  • Itches intensely
  • Can occur anywhere on the body that comes into contact with the oil from the plant
  • Commonly appears straight lines or streaks across the skin, but can appear in any shape or pattern
  • Can cause skin areas to break out at different times
    • This may make it seem as if the rash is spreading, but leakage of blister fluid does not spread the rash
    • The rash is spread by exposure to the oil from the plant which can linger on hands, under fingernails, on clothing, shoes, and gardening tools
  • Lasts two to three weeks

What Causes Poison Ivy?

The rash caused by poison ivy is an allergic skin reaction to an oil in the plant called urushiol. Urushiol is found in all parts of the plant, including the leaves, stems, roots, sap, and berries. 

People are exposed to the oil occurs by:

  • Touching any part of the plant
  • Touching something with urushiol on it, such as garden tools or clothing
  • Touching pets or animals exposed to the oil
  • Inhaling smoke from burning poison ivy plants

Is Poison Ivy Contagious?

Poison ivy rash is not contagious. It is not transmitted from person-to-person. However, if there is still urushiol (the oil found in poison ivy that causes the rash) present on a person’s skin or clothing, touching that oil may cause a rash.

How Is Poison Ivy Diagnosed?

Poison ivy rash is generally diagnosed with a skin examination and by the appearance of the rash alone. No additional tests are needed.

What Is the Treatment for Poison Ivy?

Poison ivy rash usually goes away on its own without treatment within one to three weeks. Treatment for the rash involves self-care at home.

  • Wash thoroughly with soap and water as soon as possible to remove the oils fast
    • Get under the fingernails
    • Rubbing alcohol can help dissolve and remove the oils from the skin
    • If the oil is able to be removed within 10 minutes, a rash is unlikely to develop

Treatments to help relieve itching, soreness, and discomfort caused by poison ivy dermatitis include:

  • Skin treatments
    • Application of cool wet compresses
    • Oatmeal baths
    • Calamine lotion 
    • Astringents containing aluminum acetate (Burow's solution) and Domeboro may help to relieve the rash once the blisters begin leaking fluid
  • Steroid creams
    • Best if used during the first few days of symptoms
    • Over-the-counter (OTC) hydrocortisone creams do not usually help; stronger prescription steroid creams may be needed 
  • Steroid pills or injections 
    • Pills (e.g., prednisone) or injections (e.g., triamcinolone acetonide, budesonide)
    • Used for severe symptoms or rash on a large area, or the face or genitals
  • Antibiotics
    • To treat skin infections, usually caused by scratching

Antihistamines are not usually used to treat poison ivy rash because they do not relieve the itching, but antihistamines that make you sleepy such as diphenhydramine (Benadryl) may help if itching is keeping you awake. Antihistamine creams or lotions, anesthetic creams containing benzocaine, or antibiotic creams containing neomycin or bacitracin are not recommended because they can make the rash worse.

References
https://www.uptodate.com/contents/poison-ivy-beyond-the-basics

https://www.uptodate.com/contents/poison-ivy-toxicodendron-dermatitis