In a 6-year-old Indian child with impetigo, which is the most common site of involvement?

Explanation

## Most Common Site of Impetigo **Key Point:** The face and other exposed areas (especially around the nose and mouth) are the most common sites of impetigo involvement, accounting for >50% of cases. ### Anatomical Distribution in Impetigo | Site | Frequency | Reason | |------|-----------|--------| | Face (perioral, perinasal) | Most common (>50%) | Warm, moist, frequent minor trauma | | Exposed areas (arms, legs) | Common | Sun exposure, minor cuts, abrasions | | Intertriginous areas | Less common | Maceration, but less typical | | Palms and soles | Rare | Thick stratum corneum, low moisture | | Scalp | Uncommon | Hair barrier, less frequent inoculation | ### Why the Face? 1. **Frequent minor trauma:** Nasal picking, scratching, insect bites 2. **Warm, moist environment:** Promotes bacterial colonization 3. **High bacterial carriage:** S. aureus colonizes anterior nares and perinasal skin 4. **Proximity to mucous membranes:** Facilitates bacterial entry 5. **Poor hygiene in children:** Hands frequently touch face **High-Yield:** In NEET PG, when asked about the most common site of impetigo, the answer is always the **face and exposed areas**. This is consistent across all major textbooks and epidemiological studies. **Clinical Pearl:** The classic presentation is perioral and perinasal crusting in a child — this is the stereotypical impetigo picture. The lesions often cluster around areas of minor trauma or breaks in the skin barrier. ### Distinction from Other Staphylococcal Infections - **Folliculitis:** Hair-bearing areas (scalp, beard, axillae) - **Erysipelas:** Face (but with sharp demarcation and systemic symptoms) - **Cellulitis:** Any site, but deeper involvement with systemic toxicity - **Impetigo:** Superficial, face and exposed areas, minimal systemic symptoms