Contact dermatitis is an inflammation of the skin caused by direct contact with an irritating substance or allergen. There are several types of contact dermatitis including, irritant contact dermatitis, allergic contact dermatitis and overtreatment dermatitis.
How do you distinguish between the different types of contact dermatitis?
It may be difficult to distinguish between these types but the hallmark of allergic contact dermatitis is that symptoms only occur at the site of contact with the offending substance.
Irritant Contact Dermatitis
Irritant Contact Dermatitis, the most common type of contact dermatitis, involves inflammation resulting from contact with acids, alkaline materials such as soaps and detergents, solvents, or other chemicals. The reaction usually resembles a burn. Irritant contact dermatitis is often more painful than itchy and it the result of actual damage to the skin by the offending agent. Soaps and detergents are the most common offenders and reaction most commonly occur on the hands. People that are excessively exposed to soaps and detergent or who have a history of eczema are most at risk for irritant contact dermatitis.
Allergic Contact Dermatitis, the second most common type of contact dermatitis, is caused by exposure to a substance or material to which you have become allergic. The allergic reaction is often delayed, with the rash appearing 24 – 48 hours after exposure. The skin inflammation varies from mild irritation and redness to open sores, depending on the type of allergen, the body part affected, and the severity of your allergy.
What are the common allergens associated with allergic contact dermatitis?
The are many allergens that may cause allergic contact dermatitis including:
- Poison ivy, poison oak, poison sumac
- Other plants
- Nickel or other metals
- Antibiotics, especially those applied to the surface of the skin (topical)
- Topical anesthetics
- Other medications
- Fabrics and clothing
- Fragrances, perfumes
- Other chemicals and substances
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.
Some products cause a reaction only when they contact the skin and are exposed to sunlight (photosensitivity). These include shaving lotions, sunscreens, sulfa ointments, some perfumes, coal tar products, and oil from the skin of a lime. A few airborne allergens, such as ragweed or insecticide spray, can cause contact dermatitis.
What are the symptoms of allergic contact dermatitis ?
Symptoms of allergic contact dermatitis are exclusive to the exposed area of skin and include:
- Redness or inflammation
- Lesions of any type: redness, rash, papules (pimple-like), vesicles, and bullae (blisters) which may involve oozing, draining, or crusting or become scaly, raw, or thickened
How is contact dermatitis diagnosed?
The diagnosis is primarily based on the skin appearance and a history of exposure to an irritant or an allergen. Patch testing is used for patients who have chronic, recurring contact dermatitis. Other tests may be used to rule out other possible causes, including skin lesion biopsy or culture of the skin lesion (see skin or mucosal biopsy culture).
Who gets contact dermatitis?
People with a history of any kind of allergy are more likely to develop allergic contact dermatitis. For instance, children who have a food allergy are more likely to have a skin allergy. People with existing skin disorders such as eczema, psoriasis, acne, or others are also more likely to get contact dermatitis.
People who work with their skin submerged in water on a regular basis are more likely to develop contact dermatitis because the water strips the skin of protective oils. The same is true for people who work outdoors or with high levels of heat such as:
- Cooks and chefs
- Glass blowers
- Factory workers
- Hair stylists
- Construction workers
- Health care workers
Repeated use of irritants can also increase sensitivity to contact dermatitis. While initial use of something like contact lens solution or wearing a watch containing nickel may not trigger an immediate response, repeated use can increase your risk for contact dermatitis symptoms.
Sunlight can also be a risk factor. Certain contact dermatitis allergens are photosensitizers; they only cause a skin reaction after they are subsequently exposed to sunlight. Common photosensitizers are perfumes and aftershave lotions that contain certain oils; soaps, detergents, and sunscreens; and some fruits and vegetables, including limes, celery, and figs. Some oral medications, including tetracycline and doxycycline, are photosensitizers as well.
What is the treatment for allergic contact dermatitis?
Treatment is determined on an individual basis as prescribed by your physician. Please contact our office to schedule an appointment with one of our allergy and asthma specialists.