Beyond Urticaria: Acute Airborne Contact Dermatitis in a Hospital Worker Presenting to the Emergency Department.

Airborne allergic contact dermatitis (ACD) is a delayed, T-cell-driven inflammatory reaction that usually develops gradually in occupational settings, so encountering an acute presentation in the emergency department is uncommon. Severe, sudden exacerbations mimicking acute allergic emergencies are uncommon and can complicate emergency department (ED) evaluation. We describe a 45-year-old hospital cleaning staff member with a five-year history of intermittent dermatitis who presented with abrupt, diffuse pruritus, marked facial swelling, and vesiculopapular eruptions shortly after working with aerosolized quaternary ammonium disinfectants. Despite the dramatic cutaneous involvement, her vital signs remained within normal limits, distinguishing the presentation from anaphylaxis or widespread urticaria. Dermatologic examination demonstrated acute eczematous inflammation overlying chronic lichenified plaques, predominantly involving exposed areas. The patient was treated with a loading dose of intravenous methylprednisolone followed by scheduled systemic steroids, dual H1/H2 blockade, and potent topical corticosteroids, achieving rapid symptomatic improvement. This case reinforces the need to consider acute occupational ACD in the ED when intense pruritus and angioedema-like swelling occur without systemic compromise, and highlights the importance of pattern recognition and long-term avoidance counselling.