Irritant contact dermatitis accounts for 80% of all contact dermatitis reactions. It occurs when the skin comes in contact with a substance that acts as an irritant. Even though over 2800 substances have been identified as irritants, almost any substance under the right circumstances can act as an irritant.
Skin Barrier in Irritant Contact Dermatitis
The epidermis acts as a barrier with an outer layer composed of dead cells in a water-protein-lipid matrix. If the barrier function of the epidermis is disrupted for any reason, an eczematous-type reaction can occur. Irritant contact dermatitis is divided into 2 subtypes depending on the strength of the irritant.
Acute Irritant Contact Dermatitis
Acute irritant contact dermatitis occurs when the skin comes in contact with a strong toxic chemical such as an acid or alkali. The rash occurs within minutes to hours after exposure and in most cases healing occurs soon after exposure. This rash usually has sharp borders and consists of redness, vesicles, bullae, or skin sloughing.
Chronic Cumulative Irritant Contact Dermatitis
Chronic cumulative irritant contact dermatitis is the more common of the two. This dermatitis occurs after repeated exposure to low-level irritants, such as soaps or shampoos. The rash may take weeks, months, or even years to develop. The rash usually has poorly-defined borders, is very itchy, and consists of redness, scaling, fissuring, and lichenification.
Treatment of Irritant Contact Dermatitis
The mainstay of treatment for irritant contact dermatitis is avoiding as many of the irritants as possible. Other helpful measures include:
- Reduce water exposure - because frequent water exposure actually dries out the skin and disrupts the barrier function of the epidermis, keep water contact to a minimum.
- Moisturize - Frequent moisturization improves the barrier function of the skin. Avoid the use of moisturizers with perfumes since these may also act as an irritant.
- Protection - Because the hands are often affected by irritant contact dermatitis, the use of gloves may help reduce exposure to the irritant.
- Topical steroids - Medium- to high-strength topical steroids may be needed to reduce inflammation and itching.