A 14-year-old boy is brought to the pediatrician's office in mid summer because of an itchy, blistering rash on his calves and forearms. The rash developed 24 hours after he returned from a weekend Boy Scout camping trip. The pediatrician suspects the lesion is caused by poison ivy. If the doctor is correct, which one of the following is NOT a prominent component in the immunologic mechanisms causing the skin lesions?

Question

Quizplus · Accepted Answer

Poison ivy rash is a form of contact dermatitis in which there is a delayed-type hypersensitivity (DTH) reaction. The patient's vesicular dermatitis was evoked by his repeated exposure to urushiol, the antigenic component of poison ivy. Endothelial adhesion molecules and chemokines mediate the recruitment of previously sensitized CD4⁺ T cells of the TH1 subset and CD8⁺ T cells, which secrete cytokines such as interferon-ƴ and activate macropha-ges. Activated macrophages release enzymes and reactive oxygen intermediates that damage cellular tissue. IgE-coated mast cells are involved in immediate hypersensitivity reactions, not DTH reactions.

A 14-Year-Old Boy Is Brought to the Pediatrician's Office in Mid