What is the hallmark symptom of allergic contact dermatitis?

The hallmark symptom of allergic contact dermatitis is pruritus, or itching. This condition arises when the skin comes into contact with an allergen, triggering an immunological response. Within hours to days after exposure, the affected area typically shows signs of inflammation, including erythema (redness), swelling, and vesiculation. However, the defining characteristic that distinguishes allergic contact dermatitis is its intense itching, which can be persistent and often leads to scratching, potentially exacerbating the inflammation and leading to secondary infections.

While other symptoms such as redness, swelling, and even pain can occur as a result of the inflammatory process, pruritus is particularly significant because it directly affects the patient's quality of life and prompts them to seek treatment. The itch sensation can be debilitating and is a primary reason why individuals with this condition seek medical attention. Understanding that pruritus is more than just an accompanying symptom but rather the key feature of allergic contact dermatitis is crucial for diagnosis and management.