Contact dermatitis caused by allergies (126930)

Do you have “dishpan hands?” Actually, persistently rough, red hands are a sign of contact dermatitis. According to the National Health and Nutritional Examination Survey, 9 percent of office visits to dermatologists are for dermatitis.

The Medical Society of the State of New York advises that contact dermatitis results from direct contact with one of many irritants or allergens. Laundry soap, cleaning products and skin soaps are often the culprit. Allergen-causing possibilities are rubber, impure metals (especially nickel), perfume, cosmetics and the dreaded poison ivy, oak and sumac. Normally, the skin does not react the first time it meets up with an allergen. Sometimes reaction occurs on the second exposure. In other cases, years or many exposures are required for hypersensitivity to a particular substance to develop. However, once sensitized, the skin will usually become inflamed within hours or days after contact.

Physicians can usually distinguish contact dermatitis from other types of dermatitis by its unusual pattern. The eruption often disappears with clear-cut margins, acute angles and geometric outlines, although poison ivy and other poisonous plants cause lines or groups of blisters.

Although the configuration of the rash aids in diagnosis, it is not so easy to determine whether an allergy or irritant is involved. The skin reaction produced by either, especially when mild, frequently looks the same. Redness or an itchy rash may be the first sign. However, blisters that form a crust, along with swelling, are more likely to appear with an allergic dermatitis, such as from poison ivy. As the inflammation lessens, the skin may scale and become thickened.

Finding the source

A person may know what caused the inflammation, for example, recent contact with a corrosive such as oven cleaner. However, if a patient has no clue, hobbies, diet, occupation, sports activities, clothing and cosmetics all come under suspicion. The location of the rash will sometimes tell the tale, except for hands, which are into everything. Lips can be sensitive to ingredients in lipstick, toothpaste or chapped-lip medications. Armpits can become allergic or irritated by ingredients in deodorants or antiperspirants.

A lifelong problem

Contact dermatitis can make its appearance as early as infancy. Acute skin problems account for one-third of visits to the pediatrician, with irritant dermatitis the most frequent type in children. A baby’s thin delicate skin can become irritated from urine and bowel movements, or it can become allergic to a chemical in diapers or medicine used to treat diaper rash.

Problems can continue into adulthood. The problem of “dishpan hands” is common to those whose hands are constantly in contact with water, soaps and detergents. Skiers are often plagued with dermatitis from exposure to cold, dry air.

Frictional irritant dermatitis can result from improperly fitted shoes. Tattooing also can be dangerous to people who have been sensitized to mercury, chromium, cobalt and cadmium. Rashes can develop in persons tattooed with salts of these metals.

Avoidance of allergens

The MSSNY advises that sensitive-skinned people, and even those with normal skin, should follow these measures to prevent contact dermatitis:

Read the labels on cosmetics. If a cosmetic causes a problem, take note of the ingredients. Fragrances and preservatives are the usual concerns, and avoid similar formulas in the future.

Wash new clothing and linens before using. Contact dermatitis is caused by formaldehyde released by chemicals in the finishing of fabrics, and sometimes by the dyes. Stick to natural fibers.

Use soaps or detergents formulated for babies’ wash if you suspect laundry products are the irritant. Avoid fabric softeners and anti-static products.

Wear vinyl gloves with cotton liners when hands are in contact with harsh cleansers. Keep hands well moisturized with a bland lotion or cream.

Learn to recognize the leaves of poisonous plants. Poison ivy and poison oak both have leaves with three leaflets. Poison sumac has leaves with 13 oval leaflets. If exposed to them, wash hands and skin thoroughly after exposure using any kind of soap. Dermatitis can also result from handling other plants, such as parsnips, garlic, onions, tomatoes, carrots and ginger.

Go to the doctor

According to the Mayo Clinic, if redness and itching do not clear up in seven days, you should consult a physician. You should make an appointment sooner if any of the following occur:

• You are so uncomfortable that you are losing sleep or are distracted from daily routines.

• Your skin is extremely painful.

• You suspect your skin is infected.

• You have tried self-care steps without success.

Your doctor may conduct patch testing on your skin to see which substances inflame your skin. In this test, your doctor will apply a small amount of various substances to your skin under an adhesive covering. During return visits, your doctor will examine your skin to see if you are allergic to any of the substances

Treatment of contact dermatitis varies, depending on the cause. For contact dermatitis, treatment consists primarily of identifying the cause of the irritation, then avoiding it. Sometimes, creams containing hydrocortisone or wet dressings that provide moisture to your skin may help relieve redness and itching. It can take up to four weeks for this type of