20 years old female from Bihar with erythematous lesion on cheek with central crusting, likely diagnosis:
**Core Concept**
Erythematous lesions with central crusting on the cheek are characteristic of impetigo, a superficial bacterial infection of the skin. Impetigo is caused by Staphylococcus aureus or Streptococcus pyogenes, leading to skin inflammation and exfoliation.
**Why the Correct Answer is Right**
The characteristic presentation of impetigo includes erythematous lesions with central crusting, typically on exposed areas of the body like the face. This is due to the bacterial infection of the skin, which leads to the release of exotoxins that cause skin inflammation and exfoliation. The lesions often resolve spontaneously, but can be treated with topical or oral antibiotics to prevent scarring and complications.
**Why Each Wrong Option is Incorrect**
* **Option A:** This choice is incorrect as it does not match the clinical presentation of impetigo. Erysipelas is a different condition characterized by a well-demarcated, raised, and erythematous lesion, often on the face or legs.
* **Option B:** This choice is not relevant as it is a type of fungal infection that typically presents with scaly, itchy patches on the skin, not erythematous lesions with central crusting.
* **Option C:** This choice is incorrect as it does not match the clinical presentation of impetigo. Ecthyma is a more severe form of impetigo that involves deeper layers of the skin, often presenting with multiple vesicles or pustules.
**Clinical Pearl / High-Yield Fact**
Impetigo is a common skin infection in children and young adults, but can occur at any age. It is often spread through direct contact with an infected person or contaminated objects, highlighting the importance of good hygiene and handwashing.
**Correct Answer:** D. Impetigo