Ulceration of Peyer’s patches occur in … infection
**Core Concept**
The question tests knowledge of **typhoid fever**, a bacterial infection caused by *Salmonella Typhi*, and its effects on the gastrointestinal tract, particularly the **Peyer's patches**. Peyer's patches are lymphoid follicles in the small intestine that play a key role in the immune system.
**Why the Correct Answer is Right**
Typhoid fever is characterized by the invasion of *Salmonella Typhi* into the bloodstream through the **Peyer's patches**, leading to their ulceration. This process involves the bacteria penetrating the intestinal mucosa, causing inflammation and ulceration of the Peyer's patches. The **Vi antigen** of *Salmonella Typhi* helps the bacteria evade the host's immune response.
**Why Each Wrong Option is Incorrect**
**Option A:** Incorrect because, although other infections can cause gastrointestinal symptoms, they are not classically associated with ulceration of Peyer's patches.
**Option B:** Incorrect as it does not specifically relate to the characteristic ulceration of Peyer's patches seen in typhoid fever.
**Option C:** Incorrect because it is not directly associated with the pathognomonic sign of Peyer's patch ulceration.
**Clinical Pearl / High-Yield Fact**
A key point to remember is that the ulceration of Peyer's patches in typhoid fever can lead to **intestinal perforation**, a serious complication. Recognizing the association between typhoid fever and Peyer's patch ulceration is crucial for early diagnosis and management.
**Correct Answer:** D. Typhoid fever