Contact Dermatitis

Also known as: Delayed Hypersensitivity, Drug Hypersensitivity

Contact dermatitis is a skin rash caused by something that touches the skin and makes it irritated and inflamed. Your skin may be red, swollen, dry, and may be cracked. Blisters may form and ooze. The rash will itch.

Contact dermatitis can form on the face and neck, backs of hands, forearms, genitals, and lower legs.

People can get contact dermatitis from lots of sources. These include:

  • Plants such as poison ivy, oak, or sumac

  • Chemicals in hair dyes and rinses, soaps, solvents, waxes, fingernail polish, and deodorants 

  • Jewelry or watchbands made of nickel

Contact dermatitis is not passed from person to person.

Talk with your healthcare provider about what may have caused the rash. A type of allergy testing called "patch testing" may be used to discover what you are allergic to. You will need to avoid the source of your rash in the future to prevent it from coming back.

Treatment is done to relieve itching and prevent the rash from coming back. The rash should go away in a few days to a few weeks.

Home care

Your healthcare provider may prescribe medicine to relieve swelling and itching. Follow all instructions when using these medicines.

General care:

  • Avoid anything that heats up your skin, such as hot showers or baths, or direct sunlight. This can make itching worse.

  • Apply cold compresses to soothe your sores to help relieve your symptoms. Do this for 30 minutes 3 to 4 times a day. You can make a cold compress by soaking a cloth in cold water. Squeeze out excess water. You can add colloidal oatmeal to the water to help reduce itching. For severe itching in a small area, apply an ice pack wrapped in a thin towel. Do this for 20 minutes 3 to 4 times a day.

  • You can also try wet dressings. One way to do this is to wear a wet piece of clothing under a dry one. Wear a damp shirt under a dry shirt if your upper body is affected. This can relieve itching and prevent you from scratching the affected area.

  • You can also help relieve large areas of itching by taking a lukewarm bath with colloidal oatmeal added to the water.

  • Use hydrocortisone cream for redness and irritation, unless another medicine was prescribed. You can also use benzocaine anesthetic cream or spray. Calamine lotion can also relieve mild symptoms.

  • Use oral diphenhydramine to help reduce itching. You can buy this antihistamine at drug and grocery stores. It can make you sleepy, so use lower doses during the daytime. Or you can use loratadine. This is an antihistamine that will not make you sleepy. Do not use diphenhydramine if you have glaucoma or have trouble urinating due to an enlarged prostate.

  • If a plant causes your rash, make sure to wash your skin and the clothes you were wearing when you came into contact with the plant. This is to wash away the plant oils that gave you the rash and prevent more or worse symptoms.

  • Stay away from the substance or object that causes your symptoms. If you can’t avoid it, wear gloves or some other type of protection.

Follow-up care

Follow up with your healthcare provider, or as advised.

When to seek medical advice

Call your healthcare provider right away if any of these occur:

  • Spreading of the rash to other parts of your body

  • Severe swelling of your face, eyelids, mouth, throat or tongue

  • Trouble urinating due to swelling in the genital area

  • Fever of 100.4°F (38°C) or higher

  • Redness or swelling that gets worse

  • Pain that gets worse

  • Foul-smelling fluid leaking from the skin

  • Yellow-brown crusts on the open blisters