Contact dermatitis may show up as an itching redness on the skin that lasts for a short time or it can be as serious as open sores that could become infected. It may result from a chemical irritant, as an allergic reaction to something the body has become overly sensitive to or from a treatment used for another skin condition. There are a variety of causes for contact dermatitis which can show up anywhere on the whole body where the skin came in direct contact with the offending agent.
Irritants
Irritant dermatitis is the most common form of contact dermatitis. The irritant can be an acid, alkaline, chemical or soap and appears on the skin like a burn area. Contact with certain metals like nickel, latex and even certain clothing fabrics like wool can be the offending irritant. Medline Plus, a publication of the National Institutes of Health, warns that irritation can come from something you have used regularly, like nail polish remover or a preservative in contact lens solution. Over time a sensitivity can develop and your skin reacts with redness, soreness or itching. The cause may seem mysterious because no new substance has been introduced to your regimen.
Allergens
Allergens form the second most common type of contact dermatitis. Poison ivy, sumac, oak and other plants may be the culprits. Especially sensitive areas like genitalia, eyelids, lips and neck areas may show a reaction quicker than calloused or thickened skin areas like the palms of hands or soles of feet. The Auckland Allergy Clinic in Australia warns that contact dermatitis may be mistaken for an anaphylactic reaction from ingesting a food or other substance. The exact allergen may only be specified through patch testing. A person may not realize she has come in contact with an allergen because it was airborne, such as fumes from burning poison ivy branches or a perfume fragrance. An anti-itch or drying lotion may be prescribed to help deal with the itching and irritation.
Topical Medications
Topical medications can cause contact dermatitis. Antibiotics used to treat an abrasion, cream meant to sooth a dry or sunburned area or a topical anesthetic can set off contact dermatitis from what Medline Plus calls overtreatment dermatitis. The reaction may not be activated until exposed to a certain condition such as sunlight. It may also be difficult to associate the catalyst with the dermatitis because the rash may only appear a day or two after exposure. The condition should be flushed with clean water and the skin shouldn't be re-exposed to the offending medication. In most cases the rash should disappear in two to three weeks time.
