Allergic contact dermatitis is the proper term for what happens when your skin comes into contact with a chemical or protein that you’re allergic to. Simply put: You’ve got a very itchy rash on your skin.

The most common cause of such itchy rashes are poison oak, poison ivy, and poison sumac, plants in the Toxicodendron family; the most common time to get them is during the spring and summer months when the kids are outside more and wearing less. Some who have come down with poison oak, ivy, or sumac rashes may also be affected by contact with related irritants such as the skin of the mango or oil from cashew nuts.

Initially, it’s hard to tell exactly when your child was exposed, as the reaction may be delayed—from a few days to a few weeks after contact. But after the first breakout, the time between exposure and rash goes down to about two days.

 Watch for These Symptoms

 How Rashes Appear and Spread

 Metal Allergy

 Identification, Avoidance, and Treatment

Watch for These Symptoms

The earliest signs of allergic contact dermatitis are redness and skin itch. With time, tiny fluid-filled blisters often develop in the same pattern, and the rash may grow. Eventually, fairly large blisters may form, and they may ooze and scab over until they look like a skin infection. Sometimes a true secondary bacterial infection will arise; it will create more scabbing and sometimes pustules or whiteheads. But the main symptom is severe itch, which is really, really uncomfortable, and not just for kids—you know just how much if you’ve ever had a bad case of poison ivy! It is possible to have skin blisters without itching, but they are probably not allergic contact dermatitis.

How Rashes Appear and Spread

The pattern of the rash corresponds to the way the plant touched the skin. For example, red lines and streaks usually mean that your child was walking through the brush when he was exposed. But covered parts of the body such as the genitals may also break out in a rash because of contact with the plant oils, which can remain under the fingernails or in clothing for hours.

When his face and ears are covered by a heavy rash, it may be that your child was standing close to burning brush and that airborne exposure was the culprit. Or let’s say he just was eating fruit from a whole mango and he’s got tiny blisters on the outer surfaces of his upper and lower lips. You can be pretty sure his lips touched the mango skin.

Metal Allergy

Another common form of allergic contact dermatitis is from the metal nickel. Nickel is often found in metal snaps, zippers, belt buckles, and jewelry. Your child will get itchy red patches and bumps, and in chronic cases thickening of the skin due to rubbing. Occasionally a person will get tiny blisters that ooze and scab over. Look for these rashes near the belly button (usually from contact with belt buckles, metal snaps, or zippers), earlobes (metal earrings and earring posts), and other common places for jewelry (wrists, neck, fingers, etc.). As an infant, your child may have developed a rash where his skin came in contact with the metal snaps on his onesies or undershirts.

Identification, Avoidance, and Treatment

Your most important goals are to lock on to what’s causing the allergic reaction and then avoid it like the plague. Get your identifications straight: poison ivy—three-leaved, spiked green plant with red stem; poison oak—three-leaved with serrated edges; and poison sumac—fernlike leaves with fruit that grows between the leaf and the branch. If you don’t have a botanist in the family, a book with lots of pictures of plants is always helpful.

To be on the safe side, you can apply newer creams now available to exposed skin before you take your children to the park or on a hike. These creams are especially useful for kids with a history of allergies or severe reactions to the plants. Avoiding nickel is relatively simple: Choose clothing or jewelry with no nickel! If you’re not sure which metal is which, tuck your child’s shirts into his pants so the snaps don’t touch his skin, or coat the surfaces of an item like the underside of a belt buckle with several applications of clear nail polish.

Once contact dermatitis has developed, treatment is usually a combination of cool compresses, topical steroid creams and oral antihistamines. Oral antibiotics may be necessary if your child gets a secondary infection, and once in a while oral steroids are necessary with a severe reaction. If left untreated, most of these rashes will clear on their own over two to four weeks—but your child will be very, very uncomfortable.