Ahmed has worked as a phlebotomist in the local hospital for the last 7 years. Last year, he began to complain of watery, nasal congestion and wheezing whenever he went to work. He suspected he was allergic to something at the hospital because his symptoms abated when he was at home over the weekends. One day, he arrived at work for the morning shift and put on his gloves. Within minutes, he went into severe respiratory distress requiring treatment in the emergency ward. It was determined at that time that his allergic response was due to latex exposure.
1. Ahmed experienced a type I, IgE-mediated hypersensitivity response. How can this be determined by his signs and symptoms? How might another type of latex hypersensitivity reaction present?
2. How do T2H cells, mast cells, and eosinophils function to produce the signs and symptoms typical of a type I hypersensitivity disorder?
3. How is it that someone who does not come into direct contact with latex can still have a hypersensitivity response to the material? What do food allergies have to do with latex allergies?
Expert Solution Preview
Introduction:
This case study highlights a scenario where Ahmed, a worker at a local hospital, developed severe respiratory distress due to latex exposure. The following sections provide answers to the three questions posed in the scenario.
1. Ahmed experienced a type I, IgE-mediated hypersensitivity response. How can this be determined by his signs and symptoms? How might another type of latex hypersensitivity reaction present?
The signs and symptoms that Ahmed experienced, such as watery nasal congestion and wheezing, are indicative of a type I, IgE-mediated hypersensitivity response. This type of reaction occurs when the body’s immune system overreacts to an allergen, such as latex, and produces excessive amounts of IgE antibodies. Mast cells and basophils then release histamine, leading to inflammation and constriction of the airways. Another type of latex hypersensitivity reaction, such as a type IV delayed hypersensitivity reaction, would present as a localized rash or contact dermatitis rather than respiratory distress.
2. How do T2H cells, mast cells, and eosinophils function to produce the signs and symptoms typical of a type I hypersensitivity disorder?
T2H cells are helper T cells that activate B cells to produce IgE antibodies. When IgE antibodies bind to an allergen, mast cells and basophils release histamine and other inflammatory mediators, leading to vasodilation, increased vascular permeability, and smooth muscle contraction. Eosinophils also play a role in the response by releasing toxic granules that damage tissues.
3. How is it that someone who does not come into direct contact with latex can still have a hypersensitivity response to the material? What do food allergies have to do with latex allergies?
Someone who does not come into direct contact with latex can still have a hypersensitivity response due to cross-reactivity between latex and certain foods, such as bananas, avocados, and kiwis. These foods contain similar proteins to those found in latex, and thus the body’s immune system can mistake them for the allergen. Individuals with latex allergies are often advised to avoid these foods as well.
