Impetigo is a highly infectious superficial skin infection caused by Staphylococcus aureus and Streptococcus pyogenes. A skin defect usually precedes infection, and this can be in the form of a scratch or abrasion, or a skin condition such as eczema.
Classification
| Classification | Description |
|---|---|
| Bullous impetigo | Due to Staphylococcus aureus, which produces an exfoliative exotoxin (exfoliatin) that cleaves desmoglein 1 complexes, producing a split between the stratum granulosum and stratum spinosum |
| Non-bullous impetigo | Caused by Staphylococcus aureus and Streptococcus pyogenes |
| Ecthyma | A deeper infection due to Staphylococcus aureus and Streptococcus pyogenes |
- Spread
- Direct contact with discharges from the scabs
- Indirect spread via toys, clothing, equipment, and the environment
- Signs and symptoms
- Bullous impetigo: pustules, blisters → yellowish/brown crust
- Non-bullous impetigo: red sore that discharges pus or fluid → yellowish/brown crust
- Ecthyma may show Lymphadenopathy in the affected area
- Treatment
- Personal hygiene
- Topical 1% hydrogen peroxide for localised non-bullous impetigo (provided the patient is systemically well)
- Topical antibiotics, e.g., fusidic acid or mupirocin (for MRSA/fusidic acid resistance)
- Systemic antibiotics, e.g., flucloxacillin for widespread, bullous impetigo or if the patient is systemically unwell
- Exclude the child from school until the lesions are crusted and healed or 48 hours after starting antibiotics
- Complications
- Post-streptococcal glomerulonephritis
- Rheumatic fever
