Contact Dermatitis

When certain substances come into contact with your skin, they may cause a rash called contact dermatitis. Irritant contact dermatitis is often more painful than itchy, and is caused by a substance damaging the part of your skin it comes into contact with. The longer your skin is in contact with the substance, or the stronger the substance is, the more severe your reaction will be. These reactions appear most often on the hands and are frequently work-related.

Allergic contact dermatitis is best known by the itchy, red, blistered reaction experienced after you touch poison ivy. This allergic reaction is caused by a chemical in the plant called urushiol. You can have a reaction from touching other items the plant has come into contact with. However, once your skin has been washed, you cannot get another reaction from touching the rash or blisters. Allergic contact dermatitis reactions can happen 24 to 48 hours after contact. Once a reaction starts, it takes 14 to 28 days to go away, even with treatment.

Nickel, perfumes, dyes, rubber (latex) products and cosmetics also frequently cause allergic contact dermatitis. Some ingredients in medications applied to the skin can cause a reaction, most commonly neomycin, an ingredient in antibiotic creams. For irritant contact dermatitis, you should avoid the substance causing the reaction. You should also avoid spilling chemicals on your skin. Gloves can sometimes be helpful. Since these reactions are non-allergic, avoiding the substance will relieve your symptoms and prevent lasting damage to your skin.

Reference information: www.aaaai.org, www.allergy.hk

The information aims to provide educational purpose only. Anyone reading it should consult physician before considering treatment and should not rely on the information above.