impetigo

Impetigo is the most common bacterial skin infection in children, with two main forms: non-bullous (70% of cases) and bullous impetigo. Non-bullous impetigo typically begins as small vesicles that rupture and form characteristic honey-colored crusts, commonly affecting the face and extremities. It's usually caused by S. pyogenes or S. aureus. Bullous impetigo is caused exclusively by S. aureus strains producing exfoliative toxins A and B, presenting as larger, flaccid bullae that rupture leaving a thin rim of scale. The infection is limited to the epidermis and spreads through direct contact or fomites. Risk factors include minor trauma, poor hygiene, crowded conditions, and warm, humid climates. Complications are rare but may include cellulitis, lymphangitis, and post-streptococcal glomerulonephritis (with S. pyogenes). Treatment involves topical antibiotics (mupirocin) for localized disease or oral antibiotics (cephalexin, clindamycin) for extensive infection.