The rash itself is not contagious, and the fluid in the blisters does not spread the rash. Poison ivy dermatitis appears as soon as four hours or as long as 10 days after the exposure, depending on individual sensitivity and the amount exposure.
It may seem like the rash is spreading if it appears over time instead of all at once. But this is either because the plant oil is absorbed at different rates on different parts of the body or because of repeated exposure to contaminated objects or plant oil trapped under the fingernails.
Unfortunately, there is no one good answer. The time it takes for poison ivy to stop spreading can vary depending on a number of factors. This includes the severity of your exposure and how sensitive you are to the plant's oils. However, in most cases, you can expect the rash to peak within 3-5 days after exposure.
The reaction usually develops 12 to 48 hours after exposure and lasts two to three weeks. The severity of the rash depends on the amount of urushiol that gets on your skin.
The symptoms are worse within 1 to 14 days after touching the plant, but they can develop up to 21 days later if one has never been exposed to urushiol before. The blisters can occur at different times in different people; blisters can develop on the arms several days after blisters on the hands developed.
With each contact the poison ivy allergic reaction can become worse, leading to increasingly severe dermatitis. The allergy is not life-threatening, but it certainly can be uncomfortable.
Allergic contact dermatitis from poison ivy almost always results in a rash that usually lasts two to three weeks before it completely goes away.
Typically, the skin becomes red, itchy, and swollen and blisters will appear. After a few days, the blisters may become crusty and start to flake off. The rash that people get from poison ivy can take 2 to 3 weeks to heal.
How to know if you have poison ivy. A poison ivy rash will be red on light-skinned individuals and comes with itching, swelling and sometimes blisters. Inhaling smoke from burning poison ivy can cause difficulty breathing.
While most allergic reactions to poison ivy, poison oak, or poison sumac are easily managed at home, you should call your healthcare provider right away if: The rash covers all or most of your body. You are unable to stop the itching or if it feels like all of your skin is itching.
It takes time for the rash to appear. A rash can develop in a few hours if you've had a rash from one of these plants before. If you've never had a rash from poison ivy, oak, or sumac, it can take 2 to 3 weeks before you see a rash.
Poison ivy, poison oak and poison sumac all have an oily resin throughout the plant that can create an allergic reaction that lasts for weeks.
Even though your rash can go away on its own in 1 to 3 weeks, your skin will feel better if you take some steps at home. To help with oozing problems, try over-the-counter creams or lotions that you put on the rash, such as those that contain: Aluminum acetate (Burow's solution) Aluminum sulfate.
Poison ivy rashes cause mild (but annoying) symptoms that go away within a week or two. Rarely, a skin rash can last for longer than a month. Try not to scratch. Scratching can break open skin and cause an infection.
How Long Does a Poison Plant Rash Last? Most rashes caused by poison ivy, poison oak, or poison sumac are mild and last from five to 12 days. In severe cases, the rash can last for 30 days or longer.
The oil from poison ivy is known to linger. According to the FDA, it can stick around on surfaces, sometimes for years, until it is washed away using water or rubbing alcohol.
Applying a slurry of baking soda and water to the affected area. This can help dry out the rash and reduce itchiness. Rubbing the affected area with a raw potato.
The rash that occurs from contacting poison ivy can develop into a systemic problem; that is, it can spread through the body internally. When that happens the situation becomes more serious, affecting T-cells in the immune system.
The severity of dermatitis secondary to poison ivy and oak depends both on the sensitivity of the individual as well as the degree of exposure. Symptoms can range from localized erythema and mild pruritus to profound erythema, edema, severe pain, severe pruritus and bulla formation.
Poison Ivy Rashes
Most rashes caused by poison ivy are mild and typically last about 5 to 12 days. In more severe cases, the rash can last up to 30 days or more.
The available steroid over-the-counter or nonprescription is hydrocortisone (Cortizone-10®). Antihistamines, especially diphenhydramine (Benadryl®), are often used to help relieve symptoms associated with allergic reactions; however, the role of these agents in relieving symptoms of poison ivy are limited.
At night, the body's production of corticosteroids that reduce inflammation also slows down. It releases more cytokines at night, which increases inflammation. A combination of these two factors can make night itching worse.
That new spots are appearing every day," Dr. Brian Horvath, of Horvath Dermatology, said. It's not actually spreading, nor can you touch the rash and spread it to other areas. What's happening is the plant oil is coming from somewhere, and you may not realize it.
Serious complications from poison ivy are rare but can arise, which is why it's important to seek medical advice if the rash is widespread, if skin swelling continues and blisters ooze pus, if you are having difficulty breathing or develop a fever greater than 100F, or if the rash doesn't get better within a few weeks.