The difference between skin irritation and contact dermatitis

2/22/2018, 12:30 p.m.
According to the National Health and Nutritional Examination Survey, 9 percent of office visits to dermatologists are for dermatitis.
Elderly hands Wikipedia

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 ivies. Normally, the skin does not react the first time it meets up with an allergen. Sometimes it occurs on the second exposure. In other cases, it takes years or many exposures 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 pants 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 might be the first sign. However, blisters that form a crust, along with swelling, are more likely to appear with an allergic dermatitis, such as poison ivy. As the inflammation lessens, the skin might scale and become thickened.

Finding the source

A person might 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 the diaper 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 when tattooed with salts of these metals.

Avoidance to allergens

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