Non-Bullous Impetigo
A 5-year-old girl has a rash around the nose and mouth for 4 days. It began as small blisters that ruptured, leaving 6 erosions of 5 to 15 mm covered by thick golden-yellow crusts, with new lesions along a scratch line. She is afebrile and well, with no bullae, no mucosal ulcers and no lymphadenopathy. Two nursery classmates have similar crusted facial lesions. What is the most appropriate treatment?
- A.Topical mupirocin ointmentCorrect
- B.Topical acyclovir cream
- C.Topical hydrocortisone cream
- D.Oral fluconazole suspension
Explanation
Honey-coloured crusted erosions on the face of a young child, spreading by autoinoculation and occurring in nursery outbreaks, describe non-bullous impetigo, a superficial bacterial infection of the epidermis caused mainly by Staphylococcus aureus and less often by group A Streptococcus. When lesions are few, localized and there are no systemic features, a topical antibiotic such as mupirocin or fusidic acid applied 3 times daily for 5 days is the treatment of choice, matching oral therapy in efficacy with fewer adverse effects and less selection pressure. Oral antibiotics such as cephalexin or flucloxacillin are reserved for numerous or widespread lesions, bullous impetigo, systemic symptoms or outbreak control failure. Antiviral therapy would apply to herpes simplex, which produces grouped vesicles on an erythematous base with a burning prodrome, recurrence at the same site and possible mucosal ulcers rather than thick golden crusts. Topical corticosteroids treat eczema, and applying them to an untreated bacterial infection worsens and spreads it. Antifungals treat tinea, which forms annular scaly plaques with central clearing rather than crusted erosions. Children should be kept from nursery until 24 to 48 hours of treatment, with hand hygiene, separate towels and nail trimming to limit spread. Post-streptococcal glomerulonephritis remains a possible sequela of streptococcal impetigo and is not prevented by antibiotic treatment, whereas rheumatic fever does not follow skin infection.
Why each option
- A.
- Correct. Localized non-bullous impetigo is treated with a topical antibiotic such as mupirocin for 5 days.
- B.
- Acyclovir treats herpes simplex, which causes grouped vesicles and mucosal involvement, not honey-coloured crusts.
- C.
- Topical steroids treat eczema and will worsen an untreated bacterial skin infection.
- D.
- Antifungals treat tinea, which presents as annular scaly plaques with central clearing.
Reference: Nelson Textbook of Pediatrics, 22nd ed., 2024
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