It’s almost inevitable that time spent outdoors in the summer will result in someone coming home with a rash.

Poison ivy is a common culprit, causing an allergic reaction that results in a blistery, itchy red rash on nearly everyone who unwittingly encounters it. A poison ivy rash usually happens 24-72 hours after exposure to an oily coating on certain plants.

The poison ivy rash is a form of contact dermatitis, which is caused by direct contact with an irritating substance or a substance that causes an allergic reaction. Allergic dermatitis can prompt an itchy rash with blisters or bumps. Common causes of allergic dermatitis include nickel (found in jewelry, metal hooks or buttons on clothing), poison ivy or latex.

Other common skin rashes include:

• Heat rash. As the name implies, this type of rash is more common in hot, humid weather and occurs when the flow of sweat is obstructed — often due to hot weather or overdressing. You may experience prickly heat, small red bumps that have a stinging or pricking sensation, or clear, fluid-filled bumps on your skin. These types of rashes will often disappear when the skin cools. A cool compress or bath may help as well. You can avoid this type of rash by wearing loose-fitting clothing and avoiding excessive heat or humidity.
• Intertrigo. This type of skin rash is caused by skin-to-skin contact, often in warm, moist areas of the body (such as in the folds of the skin of the abdomen, in the groin area, under the breasts or between the toes). Intertrigo causes inflammation of the skin and may cause the affected area to be painful. Wearing loose-fitting clothing and using powder to help keep the area dry may help. Intertrigo can also cause a bacterial or fungal infection in the affected area. If this happens, you may need medication.
  Depending on the cause, the appearance of the rash can vary. Some rashes are dry and itchy, others are blotchy or form large hives.

Over-the-counter hydrocortisone cream will usually ease symptoms of rashes caused by allergies, such as poison ivy or poison oak. Sometimes, a poison ivy outbreak can require further medical attention.

See your primary care doctor if your rash comes with:

• Joint pain
• A sore throat
• A fever slightly above 100.4°F (38°C). Fevers with a rash could indicate a disease such as measles, shingles or scarlet fever.
• Red streaks or tender areas near the rash
• A recent tick bite or other insect bite. Ticks can transmit Lyme disease, which can cause a bullseye-shaped rash, among other symptoms.
• Swelling of the tongue and/or lips, vomiting or trouble breathing. This can indicate a severe, life-threatening allergic reaction and requires immediate medical attention.

Also see a doctor if:

• The rash hurts.
• The rash is all over your body.
• The rash appears suddenly and spreads quickly. This can happen with a severe allergic reaction, which requires immediate medical attention.
• The rash becomes infected.
• The rash doesn’t appear to be improving within 48 hours.

In the meantime, be gentle with your skin when you have a rash:

• Use mild cleansers and avoid scented bar soap.
• Wash with lukewarm water, not hot water, which can be drying.
• Pat the rash dry, don’t rub.
• Don’t cover the rash with gauze or clothing.
• Stop using makeup or lotion that may have triggered the rash.
• Try not to scratch the rash. Scratching could make it worse and could lead to infection.
• Apply an over-the-counter hydrocortisone cream to the rash if it’s itchy. Calamine lotion can also help relieve rashes from chickenpox, poison ivy or poison oak.

Rashes are some of the most annoying symptoms we deal with, but the right medical care will have you comfortable in your own skin in no time.

Julie Lopatka, M.D., is a pediatrician with Edward-Elmhurst Medical Group. View her profile and schedule an appointment online.

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