Question

A nurse is explaining to a new nurse what causes contact dermatitis. Which of the following best describes the pathophysiology of this condition?

A) Genetic mutations leading to skin inflammation
B) Excessive sweating and poor hygiene
C) Direct skin contact with irritants or allergens
D) Imbalance in skin microbiota

Answer 1

Contact dermatitis is caused by direct skin contact with irritants or allergens, leading to a type IV hypersensitivity reaction mediated by T cells, resulting in symptoms like redness and itching.

Step-by-step explanation:

The pathophysiology of contact dermatitis involves direct skin contact with irritants or allergens that trigger an immune response. This condition is classified as a type IV hypersensitivity reaction, which is a delayed response mediated by T cells. Contact dermatitis can occur upon exposure to substances like poison ivy, nickel, or latex, where the individual has typically been sensitized during a previous exposure. Upon subsequent contact, memory T cells get reactivated, leading to the production of inflammatory cytokines that stimulate macrophages and cytotoxic T cells to induce an inflammatory lesion. This results in symptoms such as redness, itching, and swelling at the site of exposure.