Which is not a feature of tropical eosinophilia –
**Core Concept**
Tropical eosinophilia is a condition characterized by an exaggerated eosinophilic response to parasites, particularly filarial worms. It is a manifestation of a type II hypersensitivity reaction, where the immune system produces IgE antibodies that bind to mast cells, leading to the release of histamine and other chemical mediators, resulting in inflammation and tissue damage.
**Why the Correct Answer is Right**
Tropical eosinophilia is characterized by a marked increase in eosinophils, elevated serum IgE levels, and the presence of microfilariae in the peripheral blood. The condition is often associated with a type II hypersensitivity reaction, which involves the activation of eosinophils and the release of granules that cause tissue damage. This is a key feature of tropical eosinophilia, and the correct answer should reflect this.
**Why Each Wrong Option is Incorrect**
* **Option A:** Elevated eosinophil count is a hallmark of tropical eosinophilia, making this option incorrect.
* **Option B:** Elevated serum IgE levels are also a feature of tropical eosinophilia, making this option incorrect.
* **Option D:** The presence of microfilariae in the peripheral blood is a diagnostic feature of tropical eosinophilia, making this option incorrect.
**Clinical Pearl / High-Yield Fact**
Tropical eosinophilia is a classic example of a type II hypersensitivity reaction, and it's essential to remember that this condition is characterized by an exaggerated eosinophilic response to parasites.
**Correct Answer:** C.