Contact Dermatitis
What is contact dermatitis?
Contact dermatitis is a rash caused by physical contact with a substance that irritates the skin or elicits an allergic reaction. The rash may develop immediately or evolve with time. Contact dermatitis and allergic reactions can impact quality of life but are rarely life-threatening.
What substances cause contact dermatitis?
Common substances that cause contact dermatitis include soap, fragrances, metals (nickel, cobalt), topical medications, cosmetics, jewelry, latex and poison ivy. More than 3,000 substances have been identified as causing contact dermatitis.
- Soaps, detergent, shampoos, hair dye and skin creams can cause a rash immediately upon contact. Keep in mind, some ingredients cause a rash that takes several days to develop, while other substances may not cause a rash until the skin is exposed to the sun.
- An allergy to nickel can develop suddenly from new jewelry but also from jewelry worn for a long time. The rash may contain pustules, dry skin and itch.
- Plant rashes develop from the oily coating of resin on the plant which when left on the skin can cause redness, swelling, itching and blistering. Even if you wash immediately after exposure it will limit your rash, but it is still possible to miss some of the plant oil. Scratching can infect the skin and distribute the plant oils, leading to the rash spreading.
What are the symptoms of contact dermatitis?
Symptoms range from:
- Itchy skin to dry, cracked skin
- Bumpy, scaly rash
- Burning and stinging
- Swelling
- Hives
- Blisters
- Oozing blisters
- Chapped skin
Who is at risk for contact dermatitis?
Anyone can develop contact dermatitis, but some occupations put workers at risk including health care workers, beauticians, bartenders, chefs, construction workers, janitors, mechanics and plumbers.
People with asthma, hay fever or eczema are at increased risk for contact dermatitis. People who work in extreme conditions of heat or cold, high humidity or very dry air are at risk.
How is contact dermatitis diagnosed?
Dr. Heather Higgins will examine your skin and ask you about what you think caused the rash, what you may have been exposed to, your symptoms and medical history. When a contact allergic reaction is suspected, Dr. Higgins may recommend patch testing.
What is patch testing?
A patch test is different from the allergy test where a doctor pricks the skin of your back to test for allergies to grasses, pollen, weeds, mold, etc. Patch testing looks for reactions to substances that come into physical contact with the skin, for example:
- Chemicals
- Metals
- Preservatives
- Soaps
- Detergents
- Fragrance
- Topical Medications
- Plant Resins
It is a painless in-office procedure. Small, postage-stamp sized patches containing allergens are applied to the skin on the back and worn for 48-72 hours. The patches must be kept dry to get an accurate reading. The patient returns, the patches are removed, and the doctor looks for signs of an allergic reaction.
What are the treatments for a rash?
If the cause can be identified, the treatment will be to avoid the substance and Dr. Higgins may order oral and topical medications to treat the rash. Mild rashes can be treated with moisturizer, OTC corticosteroid creams, oatmeal baths and an antihistamine. A severe rash that oozes and crusts will cause Dr. Higgins to look for a disease origin. Oral prednisone and antibiotic may be prescribed. Light therapy can calm the immune response.
When you develop a rash and can’t determine the cause, don’t scratch, just clean the skin with mild soap and water, try over-the-counter hydrocortisone cream to decrease the itch, and if you suspect an allergic reaction, take an antihistamine. If the rash and symptoms don’t resolve within a few days, call our office.
