Contact dermatitis is a skin condition. It occurs when a substance comes into contact with the skin and triggers inflammation. Contact dermatitis is either an allergic or an irritant reaction.
The main symptoms of contact dermatitis are as follows:
- Skin rash
- Dry skin
The rash only appears where the skin has had direct contact with the substance. Contact dermatitis most commonly affects the hands, as they're more exposed to foreign substances than other parts of the body. The skin reaction may include redness, swelling, or even blisters. It generally appears 1248 hours after contact with the substance.
Causes and triggers
Contact dermatitis can be triggered by allergens or irritants.
The majority of cases are irritant contact dermatitis. A substance irritates the skin, breaking through its protective barrier and causing damage. The following products most frequently cause skin irritations:
- Chemical products (e.g., products used in the workplace)
Allergic contact dermatitis is triggered by an immune response. The immune system perceives the substance as an attacking enemy and tries to fend it off, causing inflammation. The following substances most frequently cause allergic reactions:
- Metals (e.g., nickel in certain jewelry, cobalt)
- Perfumes and scented products (e.g., shampoos, soaps)
- Certain medications
In both types of contact dermatitis, the skin may become inflamed upon initial contact or after prolonged exposure to the substance.
Treating contact dermatitis involves finding and eliminating the source of the inflammation. As long as you're exposed to the irritant or allergen, the redness and itching will persist. Symptoms generally disappear 1 to 3 weeks after your last exposure to the substance. If eliminating the source of the inflammation is impossible, you can try to limit your exposure (e.g., by wearing gloves at work).
Cortisone creams are often prescribed to treat dermatitis. Cold compresses can also be applied to relieve itching. In more severe cases, oral medications may be necessary.
When should I see a health care professional?
Speak with your health care provider if you develop any of the following symptoms:
- Severe itching
- A swollen rash, with or without blisters
- Signs of infection (e.g., fever, heat around the affected area, increased redness, pain)
For more information:
Canadian Centre for Occupational Health and Safety