Allergic contact dermatitis.

Abstract

THE JOURNAL OF FAMILY PRACTICE | OCTOBER 2023 | VOL 72, NO 8 Allergic contact dermatitis (ACD) is an inflammatory condition of the skin caused by an immunologic response to 1 or more identifiable allergens. A delayed-type immune response (type IV hypersensitivity reaction) occurs after the skin is re-exposed to an offending allergen. Severe pruritus is the main symptom of ACD in the early stages, accompanied by erythema, vesicles, and scaling in a distinct pattern corresponding to the allergen’s contact with the skin. Delayed widespread dermatitis after exposure to an allergen—a phenomenon known as autoeczematization (id reaction)—also may occur. The gold-standard diagnostic tool for ACD is patch testing, in which the patient is re-exposed to the suspected contact allergen(s) and observed for the development of dermatitis. However, ACD can be diagnosed with a detailed patient history including occupation, hobbies, personal care practices, and possible triggers with subsequent rashes. Thorough clinical examination of the skin is paramount. Indicators of possible ACD include dermatitis that persists despite use of appropriate treatment, an unexplained flare of previously quiescent dermatitis, and a diagnosis of dermatitis without a clear cause. Hairdressers, health care workers, and metal workers are at higher risk for ACD. Occupational ACD has notable socioeconomic implications, as it can result in frequent sick days, inability to perform tasks at work, and in some cases job loss. Patients with atopic dermatitis have impaired barrier function of the skin, permitting the entrance of allergens and subsequent sensitization. ACD is a challenge to manage, as complete avoidance of the allergen may not be possible. The underrepresentation of patients with skin of color (SOC) in educational materials as well as socioeconomic health disparities may contribute to the lower rates of diagnosis, patch testing, and treatment of ACD in this patient population.