Slapped-cheek appearance is seen in:
**Core Concept**
Erythema infectiosum, also known as fifth disease, is a viral exanthem caused by parvovirus B19. It is characterized by a distinctive "slapped-cheek" appearance due to a facial rash.
**Why the Correct Answer is Right**
The slapped-cheek appearance in erythema infectiosum is a result of the virus's effect on erythropoiesis, leading to a decrease in red blood cell production. This causes a decrease in hemoglobin, which leads to a characteristic erythematous rash on the cheeks. The virus primarily affects young children and is highly contagious.
**Why Each Wrong Option is Incorrect**
* **Option A:** This option is incorrect because the slapped-cheek appearance is not typically associated with measles, which has a distinct morbilliform rash.
* **Option B:** This option is incorrect because rubella, or German measles, has a rash that starts on the face but does not have the characteristic slapped-cheek appearance.
* **Option C:** This option is incorrect because Kawasaki disease is an acute febrile illness that affects children and has a rash, but it does not typically have the slapped-cheek appearance.
**Clinical Pearl / High-Yield Fact**
Erythema infectiosum is highly contagious and can cause significant anemia in individuals with underlying hemoglobinopathies, such as sickle cell disease.
**Correct Answer:** D.