Contact dermatitis is a skin rash that occurs due to contact with irritants or chemicals. This skin condition may be short term (acute) or long term (chronic) and is often referred to as ‘chemical rash’ or ‘housewife’s eczema’. Usually clearly evident patches occurs on the area of the body that makes contact with the irritant or chemical that causes the rash.

In contact dermatitis, the skin inflammation may occur as a result of irritation to the skin or as an allergic response to the chemical.

Where does contact dermatitis occur?

Affected Areas of Contact Dermatitis

Contact dermatitis can occur on any area of the body but usually affects the hands due to touching or handling the irritant. Other common areas, include the exposed areas of the body like the face, neck and arms. In cases where contact dermatitis is caused due to contact with certain textiles and cloth dyes, the dermatitis will clearly occur at the area of the skin making contact with the clothing. Contact dermatitis may slowly spread beyond the area of initial contact.

Why does contact dermatitis occur?

Causes of Contact Dermatitis

The main cause of contact dermatitis is a skin hypersensitivity to certain chemicals. Certain substances like soaps, detergents, acids and alkalines are the most common irritants although some sufferers may even react to water. These substances are known to irritate the skin and individual tolerance to the period of exposure to the causative chemical may vary from person to person.

In most cases of contact dermatitis, the sufferer may have been exposed to the causative substance for years and not suffered with any reaction. The sudden onset of the skin rash may be puzzling and often the causative substance is not immediately identified. Many industrial workers, exposed to metal compounds, dyes, textiles and cosmetics may also develop contact dermatitis.

Using certain drugs can also make the skin more sensitive to certain compounds which eases once the drug is discontinued. In cases of allergic contact, the body’s immune system reacts to the presence of certain chemicals causing a typical rash that looks like urticaria (hives).

What does contact dermatitis look like?

Signs and Symptoms of Contact Dermatitis

In most cases of contact dermatitis, a skin rash may appear a few hours to days after exposure to the causative factor. Usually the rash appears red, slightly raised or swollen and severe itching may be noted. If the causative chemical or allergen is removed, the rash usually settles within a few days. Prolonged exposure to the cause may result in tiny blisters (vesicles) which can grow into larger fluid filled blisters (bullae). These blisters may burst, releasing the fluid inside and causing the skin to crust and peel. Constant irritation can cause the skin to thicken or discolour at the site of irritation, usually a dark discoloration of the skin.

In cases like housewife’s eczema, constant exposure to soap and water due to washing clothes and dishes causes contact dermatitis. The frequent exposure to water and constant irritation may also predispose the skin to a fungal infection.

How is contact dermatitis treated?

Treatment of Contact Dermatitis

Identifying the causative substance should be the main priority and discontinue exposure to the irritant. In some cases, especially in terms of the sufferer’s job, this may not be possible and barrier skin applications like petroleum jelly will reduce the contact between the skin and the chemical. Sunlight and strong scented creams or soaps should be avoided as they can further aggravate the dermatitis. Bathing the affected area in cool water may reduce the itching and redness but this is only a short term solution.

Antihistamines are not usually effective in treating contact dermatitis but may offer temporary relief from the itching. Corticosteroids may be effective, both for topical applications as well as oral administration. It is important to use an emollient to moisturize and protect the skin, especially in cases where the skin is dry and peeling.