Allergic contact dermatitis (ACD) is traditionally recognized as a T-cell-mediated delayed-type hypersensitivity reaction. However, many patients with ACD have been reported to experience rapid-onset ACD reactions within hours of re-exposure on skin areas previously exposed to the contact allergen. In this study, three nickel-allergic patients were patch tested for nickel twice at the same skin site over 21 days. The results demonstrated that neutrophils are rapidly recruited to the skin sites previously exposed to nickel, leading to the rapid onset of ACD. Considering that many patients with ACD are frequently re-exposed to contact allergens on the same skin areas in their daily lives, we propose that mechanisms involved in neutrophil recruitment could be potential targets for future ACD treatment.