Contact dermatitis is a common inflammatory skin condition that occurs when the skin reacts to external substances, leading to redness, itching, swelling, and discomfort. It is broadly classified into two main types: irritant contact dermatitis and allergic contact dermatitis. While both present with similar symptoms, their underlying mechanisms and triggers differ, making accurate diagnosis and management essential.

Irritant contact dermatitis results from direct damage to the skin barrier caused by repeated exposure to irritants such as soaps, detergents, chemicals, solvents, and water. It is the most common form and often develops gradually, particularly in individuals with frequent occupational exposure. Allergic contact dermatitis, on the other hand, is an immune-mediated reaction that occurs after sensitization to a specific allergen such as nickel, fragrances, preservatives, rubber compounds, or certain topical medications.

Clinically, contact dermatitis presents with redness, itching, dryness, scaling, and sometimes blistering or oozing. Symptoms are usually confined to areas of direct contact but may spread in severe cases. Chronic exposure can lead to thickened skin, fissures, and pigmentation changes, significantly affecting quality of life.

Diagnosis is primarily clinical, supported by a detailed history of exposures, occupational risks, personal care products, and symptom patterns. In suspected allergic contact dermatitis, patch testing may be used to identify specific allergens. Differentiating contact dermatitis from other inflammatory skin conditions such as eczema or psoriasis is important to ensure appropriate management.

Management focuses on identifying and avoiding the triggering substance, restoring the skin barrier, and controlling inflammation. Patient education is central to long-term control, as repeated exposure can lead to chronic disease. With appropriate management, most cases of contact dermatitis are reversible and preventable.