Background Some patients state compliance with avoidance of identified allergens, yet have persistent dermatitis in areas under tight-fitting clothing. Objective To analyze a series of such cases to identify allergens most likely retained in clothing. Methods Review of contact dermatitis clinic cases and identification of type and formula weight of allergens involved. Results High-formula-weight allergens and allergens present in medicament ointments are difficult to dissolve in laundry detergent and water and may be retained in clothing. Conclusion Retention of allergens in clothing, even after washing, may explain recalcitrant dermatitis in a patient who states compliance with avoidance of a seemingly relevant allergen. Dermatologists should consider the possibility of allergen retention in clothing whenever a patient has only partial clearing after at least 1 month of attempted compliance with avoidance of identified allergens. Purchase of new clothing may be required to clear allergic contact dermatitis in this situation.