Irritant Contact Dermatitis Clinical Presentation

A detailed history is required because the diagnosis of irritant contact dermatitis rests on the history of exposure of the affected body site to the cutaneous irritant. Patch testing also is used in severe or persistent cases to exclude allergic contact dermatitis as a component of the individual's cutaneous manifestations.

Onset of symptoms occurs within minutes to hours of exposure in simple acute irritant contact dermatitis. Acute delayed irritant contact dermatitis is characteristic of certain irritants, such as benzalkonium chloride (eg, zephiran, a preservative and disinfectant), which elicits a deferred (8-24 h after exposure) inflammatory reaction.^[14]

The onset of signs and symptoms may be delayed by weeks in cumulative irritant contact dermatitis. Cumulative irritant contact dermatitis is a consequence of multiple incidents of subthreshold damage to the skin, with the time between exposures being too short for a full resolution of skin barrier function. Patients with sensitive skin (ie, atopic individuals) have a decreased irritant threshold or a prolonged restoration time, making them more vulnerable to clinical irritant contact dermatitis.

Cumulative irritant contact dermatitis typically occurs with exposure to weak irritants rather than strong ones. Often, the exposure (eg, water) is not only at work but also at home.

These patients report both itching and pain caused by fissuring of the hyperkeratotic skin (chapping). Pain, burning, stinging, or discomfort exceeding pruritus occur early in the clinical course.

Less important subjective criteria for irritant contact dermatitis include the onset of dermatitis within 2 weeks of exposure, and reports of many other coworkers or family members affected.

Occupational history

Irritant contact dermatitis is a major occupational disease; skin disorders comprise up to 40% of occupational illnesses. The physician needs to take an occupational history from adults with suspect irritant contact dermatitis.

Occupational irritant contact dermatitis typically affects workers who are new to a job, who are constitutionally more susceptible to irritant contact dermatitis, or who have not learned to protect their skin from cutaneous irritants. Individuals with history of atopic dermatitis (especially of the hands) are more susceptible to irritant contact dermatitis, particularly of the hands.

Most affected workers have a degree of permanent injury that is lower than that of other occupational diseases; however, the compensation pay was higher for skin diseases than for diseases of the respiratory system or musculoskeletal disorders, according to a study in Denmark.

Rietschel and Fowler proposed the following as primary diagnostic criteria for irritant contact dermatitis^[15] :

• Macular erythema, hyperkeratosis, or fissuring predominating over vesiculation
• Glazed, parched, or scalded appearance of the epidermis
• Healing process beginning promptly on withdrawal of exposure to the offending agent
• Negative results on patch testing that includes all possible allergens

Minor objective criteria for irritant contact dermatitis include the following:

• Sharp circumscription of the dermatitis
• Evidence of gravitational influence such as a dripping effect
• Lower tendency for the dermatitis to spread than in cases of allergic contact dermatitis
• Morphologic changes suggesting small differences in concentration or contact time producing large differences in skin damage

Individuals may develop a habit of continuing to rub a site initially affected by irritant contact dermatitis and may develop secondary neurodermatitis or lichen simplex chronicus (lichenification). This may be accepted as a sequela of an occupational injury.

Skin lesions may become colonized secondarily and/or infected, particularly by Staphylococcus aureus. Secondary neurodermatitis (lichen simplex chronicus) may develop in individuals with irritant contact dermatitis, particularly in those with workplace exposures or under psychological stress.

Postinflammatory hyperpigmentation or hypopigmentation may occur in areas affected by irritant contact dermatitis or persist after resolution of irritant contact dermatitis in individuals with more pigmented skin.

Scarring may occur after corrosive agent exposure, excoriation, or artifact, causing ulceration.

Irritant contact dermatitis increases the risk of sensitization to topical medications.