A 20 year old male complains of recurrent attacks of sore throat since 2 years. The total leukocyte count was 1000/μl. A differential count revealed severe neutropenia. The diagnosis is:
**Core Concept**
The underlying principle being tested is the relationship between neutropenia and recurrent infections, specifically the diagnosis of cyclic neutropenia. **Neutropenia** refers to an abnormally low level of neutrophils, a type of white blood cell important in fighting off infections.
**Why the Correct Answer is Right**
Cyclic neutropenia is characterized by periodic episodes of neutropenia, leading to recurrent infections such as sore throat. This condition is due to a fluctuation in the production of neutrophils in the bone marrow, resulting in severe neutropenia at regular intervals, typically every 21 days.
**Why Each Wrong Option is Incorrect**
**Option A:** This choice is incorrect because, although it may be related to immune system dysfunction, it does not specifically explain the cyclic nature of the neutropenia and recurrent infections.
**Option B:** This option is incorrect as it does not directly relate to the periodic fluctuation in neutrophil count.
**Option C:** This choice is not relevant to the cyclic pattern of neutropenia and infections described.
**Clinical Pearl / High-Yield Fact**
A key point to remember is that cyclic neutropenia often presents with recurrent infections, particularly of the oral cavity, due to the periodic decrease in neutrophil count, making it a critical diagnosis to consider in patients with such a history.
**Correct Answer:** D. Cyclic Neutropenia.