Question

Allergy to nickel is a well-known cause of contact dermatitis. Patches of dermatitis under a watch or on earlobes suggest that a patient should be patch-tested with a battery of commonly implicated agents, including nickel and chromate. Of what is nickel dermatitis an example?

Wheal-and-flare
Type II hypersensitivity
Type III hypersensitivity
Type IV hypersensitivity
Urticaria

Answer 1

Nickel dermatitis is an example of 4) Type IV hypersensitivity, also known as delayed-type hypersensitivity. It is a T cell-mediated immune response that occurs when the skin comes into contact with nickel.

Step-by-step explanation:

Nickel dermatitis is an example of 4) Type IV hypersensitivity. Type IV hypersensitivity, also known as delayed-type hypersensitivity, is a T cell-mediated immune response that occurs several hours to days after exposure to an allergen.

In the case of nickel dermatitis, the skin becomes red and swollen when in contact with nickel. This reaction happens because the individual has previously been sensitized to nickel and their immune system reacts to it.