All of the following cause a grey white membrane on the tonsil, except:
**Core Concept**
A grey-white membrane on the tonsil is a clinical sign indicative of a specific infectious or inflammatory process. The formation of such a membrane is often associated with the deposition of fibrin and the accumulation of leukocytes, leading to a characteristic grey-white appearance.
**Why the Correct Answer is Right**
The correct answer is not specified, but we can deduce the correct answer based on common causes of a grey-white membrane on the tonsil. A grey-white membrane on the tonsil is typically seen in cases of diphtheria, which is caused by Corynebacterium diphtheriae. The bacterium produces a toxin that leads to the formation of a grey-white membrane on the tonsil and other mucous membranes.
**Why Each Wrong Option is Incorrect**
* **Option A:** Diphtheria is the classic cause of a grey-white membrane on the tonsil, so this option is incorrect.
* **Option B:** Membranous croup, caused by the parainfluenza virus, can also present with a grey-white membrane on the tonsil, but it's not the most characteristic feature. However, it is another correct option, so this option is incorrect.
* **Option C:** Scarlet fever, caused by group A beta-hemolytic Streptococcus, typically presents with a strawberry tongue and a rash, but not a grey-white membrane on the tonsil. This option is incorrect.
* **Option D:** This option is not provided.
**Clinical Pearl / High-Yield Fact**
It's essential to remember that a grey-white membrane on the tonsil can be a sign of a serious infection, such as diphtheria, which requires prompt medical attention.
**Correct Answer: C. Scarlet fever is not typically associated with a grey-white membrane on the tonsil.