What is a common symptom of contact dermatitis?

Red, itchy skin is a hallmark symptom of contact dermatitis, which is an inflammatory reaction that occurs when the skin comes into contact with an irritant or an allergen. This condition typically manifests as redness, swelling, and itching on the affected areas of the skin. The redness results from increased blood flow to the area as part of the body's immune response, while itching is a common reaction associated with inflammation.

Sensitive skin does not specifically indicate contact dermatitis; instead, it could refer to a range of skin concerns that may not involve inflammation or an allergic reaction. Dry patches may appear in certain skin conditions, including eczema but are not exclusively characteristic of contact dermatitis. Oiliness, on the other hand, is not associated with contact dermatitis, as the condition does not typically involve excessive oil production but rather inflamed and irritated skin. Therefore, the most defining symptom of contact dermatitis is indeed red, itchy skin, making it the correct answer.