**Slapped Cheek Appearance**

**Core Concept**
Slapped cheek appearance is a characteristic clinical manifestation of Fifth disease (erythema infectiosum), caused by parvovirus B19 infection. This rash typically presents with a "slapped cheek" appearance on the face, followed by a lacy rash on the trunk and limbs.

**Why the Correct Answer is Right**
The correct answer is related to the pathophysiology of Fifth disease. Parvovirus B19 infects erythrocyte precursors, leading to a transient aplastic crisis. The slapped cheek appearance is thought to be due to the virus-induced inflammation of the small vessels in the cheeks, resulting in the characteristic erythematous rash.

**Why Each Wrong Option is Incorrect**
* **Option A:** This option is not related to the clinical manifestation of Fifth disease.
* **Option B:** This option is not a known cause of the slapped cheek appearance.
* **Option C:** This option is not relevant to the clinical presentation of Fifth disease.

**Clinical Pearl / High-Yield Fact**
The slapped cheek appearance of Fifth disease is often accompanied by mild fever, headache, and pharyngitis, and can be followed by a lacy rash on the trunk and limbs.

**Correct Answer: C. Parvovirus B19**