Allergic Contact Dermatitis
1. What is Allergic Contact Dermatitis?
Allergic contact dermatitis is an allergic skin reaction from a single exposure to usually poison oak or poison ivy resin. It may involve swelling, redness, itching, blistering, “weeping” clear fluid, crusting, formation of clear vesicles, pustules, dryness, peeling, or allergic-like reactions of the involved area. The allergic reaction is often delayed, with the rash appearing 24-48 hours after exposure. Allergic contact dermatitis caused by poison oak or poison ivy is an acute condition, generally lasting less than a month.
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2. What Does Allergic Contact Dermatitis Look Like?
Cases of allergic contact dermatitis involve multiple small, clear fluid-filled blisters on well-bordered, raised, red patches. These small blisters often burst and cause a yellow crust to form around the irritated region. Secondary bacterial infection may cause the formation of pustules, which may become tender and eventually burst. Symptoms are localized only to areas in which the resin has contacted.
3. Who Does Allergic Contact Dermatitis Affect?
Allergic contact dermatitis affects individuals working or recreating outdoors, where poison ivy or poison oak grows, throughout the United States and Southern Canada. It is generally uncommon in young children. In addition to poison oak and related plants, common allergens that cause allergic contact dermatitis include other plants, nickel or other metals, topical antibiotics (i.e. Neosporin) or other topical medications, rubber, cosmetics, fabrics and clothing (i.e. wool), fragrances, adhesives, and many others.
4. What Causes Allergic Contact Dermatitis?
Allergic contact dermatitis is caused by the immune system’s hyper-sensitive reaction to the poison oak or poison ivy resin. With an exposure, the irritating or causative agent stimulates certain antibodies to cause an amplified release of inflammatory agents from immune system cells. These agents promote itching, redness, and vesicle formation. Allergic contact dermatitis may involve a reaction to a substance that you are exposed to, or use repeatedly. Although there may be no initial reaction, regular use (for example, nail polish remover, preservatives in contact lens solutions, or repeated contact with metals in earring posts and the metal backs of watches) can eventually cause sensitivity and reaction to the product. The end result is inflammation of the skin, as well as a heightened migration of blood cells and immune system cells to the affected location.
5. What Triggers Allergic Contact Dermatitis?
Exposure to the poison oak or poison ivy resin is the main factor contributing to allergic contact dermatitis but other compounds in our environment can cause similar reactions. New rashes on different body parts may be triggered if contact is made with the initial site of exposure before the resin has been completely washed off. However, a thorough cleansing with liquid soap or detergent will remove the resin and prevent further spread. In all cases of allergic contact dermatitis, rubbing and scratching are behaviors that worsen the condition by introducing secondary bacterial infections to the involved areas.
6. How Can My Allergic Contact Dermatitis Be Treated?
For allergic contact dermatitis, topical anti-itch lotions may be given to control excessive itching and rubbing. Topical steroid creams may help reduce inflammation, and topical anti-bacterial lotions may be given to decrease secondary bacterial infections, reducing pustules at the site. In addition, a small steroid injection may help lower the hyperactive state of the immune system and shorten the duration and spread of the rash. For more information on available treatments for eczema, or to schedule a visit, please call and speak with a representative at the Berman Skin Institute.