What is a characteristic feature of the rash associated with contact dermatitis?

The rash associated with contact dermatitis is characterized by being intensely pruritic and often displaying clear vesicles. This type of dermatitis typically occurs as a reaction to an allergen or irritant that comes into contact with the skin, leading to the formation of small, fluid-filled blisters. The intense itching is a prominent symptom, making it uncomfortable for individuals affected by this condition. The presence of clear vesicles is a key indicator of contact dermatitis, indicating that the skin is reacting to an external substance.

Other characteristics, such as the rapid onset and contagious nature suggested in some options, do not apply to contact dermatitis, as it is localized to the area of contact rather than being a systemic or infectious condition. Similarly, the rash does not present with flat lesions that lack distinct margins, nor is it exclusively limited to the face and neck; it can occur anywhere on the skin that has come into contact with the irritating agent. Thus, the defining features of contact dermatitis emphasize the intense itching and clear vesicle formation, making the identification of option B accurate for this condition.