There are two basic kinds of contact dermatitis, allergic or irritant. Allergic dermatitis occurs when you have contact with an allergenic substance and it produces a delayed reaction. This may develop over a period of 48 to 96 hours, or it may take even longer, between seven and 10 days after the first exposure. Allergenic contact dermatitis can also cause oozing blisters, intense itching, and sometimes swelling in the face, eyes, or genitals. [3] X Trustworthy Source DermNet NZ Online clinical resource website written and run by dermatologists providing evidence-based information about dermatology and skin health Go to source Irritant contact dermatitis occurs when skin comes into contact with an irritant, like a detergent or solvent. Skin damage may be permanent if the irritant is powerful, like acid or lye soap. [4] X Trustworthy Source DermNet NZ Online clinical resource website written and run by dermatologists providing evidence-based information about dermatology and skin health Go to source This kind of dermatitis may also cause mild swelling, itching, blisters, painful ulcers, or tight-feeling and cracked skin. If you note a rash and think you may have come into contact with a plant like poison oak, ivy, or sumac, make sure you wash everything that may have been in contact with the plant with cold water. This includes clothing, gardening tools, sports equipment, and pets.
Is the rash on your hands or face? Contact dermatitis most often affects these areas and rarely occurs on the scalp, palms of hands or soles of the feet. Is the rash confined to the area that was exposed? A delayed reaction sometimes makes it look like a rash from contact dermatitis is spreading, but for the most part it should only occur where your skin was in contact with the irritant or allergen.
Dry skin with a glazed, parched aspect is often the first sign with irritants. Thickened skin and cracking can follow if contact continues for a longer period of time. In very severe cases of exposure to an irritant, the skin may also exhibit burns or tissue death (necrosis). Burning eyes, nose, and lungs can indicate allergic contact dermatitis, but can also point to an irritant in the air.
If you’ve been handling an irritant like a mild solvent and develop a rash on your hands, for example, the solvent is probably the cause. Were you walking outdoors and then got a rash on your legs? You might be dealing with contact dermatitis from poison ivy, poison oak, or poison sumac. People sometimes develop dermatitis from allergies to fabrics, plastics, or metals. A plastic wristwatch band can cause a reaction, for instance.
Have you been outside on a nature trail, in a wooded lot, or in scrubby area? Keep in mind that you can easily touch poison ivy or a similar plant and not realize it, leading to allergic contact dermatitis. Affected areas for these rashes are often the feet, ankles, legs, or arms. The rash will usually appear linear where the plant has brushed across the skin or resin has been spread by scratching. Have you handled cleaning products lately, like soaps, detergents, or solvents? These products can cause irritant contact dermatitis, as can rubber and latex and metals like nickel and gold. Write things down, if it helps. Keep a notebook with all the activities and items that may have led to the reaction or list anything that might have touched your skin for two days before the rash appeared.
Skin prick test can test for reaction to as many as 40 different allergens. A diluted allergen is applied with a prick to your skin. Your skin is observed for 15 minutes. A wheal, irritation, redness or itching may indicate that you are allergic to a substance that was applied. Another way to test for allergies is through a patch test. This means that you will have to wear patches containing a small amount of each substance for about 48 hours. If you react to a patch, it indicates you have an allergy. The allergist can use patch testing to check fragrances, hair dyes, rubber, and other substances. It will also detect photoallergic reactions, which occur when a substance like shaving lotion or sunscreen reacts in sunlight to cause a skin reaction.
If avoidance is not possible, apply a barrier lotion such as IvyBlock, Work Shield, Zinc Oxide paste, or Desenex prior to potential exposure. Check the labels on all products that you put on your skin for allergens or irritants, or contact the manufacturer directly. Substitute other products for ones that gives you contact dermatitis. The allergen in poison ivy may remain active for months. It is crucial for exposed clothing, shoes, tools, camping equipment and pets to be washed thoroughly to avoid spreading the allergen.
Consider using gloves. Irritant contact dermatitis often affects the hands, so gloves are an easy way to reduce contact. Use cotton gloves if you have an allergy to latex or rubber. Take your gloves off periodically, too, as sweat can aggravate dermatitis symptoms. Follow all safety instructions on protective equipment if you work with irritants.
Wash the area with Dial brand soap, GOOP (a grease removing agent), or Tecnu as these have been shown to be effective in binding to urushiol (the oil in plants that causes allergic reaction) for more thorough removal. Be sure to wash under the fingernails, too, especially if you have been scratching. Consider an after-work cream, as well, if you can’t totally avoid contact with an irritating or allergenic substance. These are designed for use after work to calm your skin and reduce the frequency and severity of reactions.
