Acute localised otitis externa
If acute localised otitis externa presents as a boil and the patient is at low risk of methicillin-resistant Staphylococcus aureus (MRSA) infection (see Risk factors for infection with methicillin-resistant Staphylococcus aureus), empirical therapy targeting methicillin-susceptible S. aureus (MSSA) is appropriate. Use:
1dicloxacillin 500 mg (child: 12.5 mg/kg up to 500 mg) orally, 6-hourly for 5 days. For dosage adjustment in adults with kidney impairment, see dicloxacillin dosage adjustment dicloxacillin dicloxacillin dicloxacillin
OR
1flucloxacillin 500 mg (child: 12.5 mg/kg up to 500 mg) orally, 6-hourly for 5 days. For dosage adjustment in adults with kidney impairment, see flucloxacillin oral dosage adjustment. flucloxacillin flucloxacillin flucloxacillin
If acute localised otitis externa presents as painful erysipelas involving the pinna and external canal, which can be caused by Streptococcus pyogenes (group A streptococcus [GAS]), use:
phenoxymethylpenicillin 500 mg (child: 12.5 mg/kg up to 500 mg) orally, 6-hourly for 5 days. phenoxymethylpenicillin phenoxymethylpenicillin phenoxymethylpenicillin
Cefalexin is often preferred to dicloxacillin or flucloxacillin in children because the liquid formulation is better tolerated. It can also be used for patients who have had a nonsevere (immediate or delayed) hypersensitivity reaction to penicillin1. Use:
1cefalexin 500 mg (child: 12.5 mg/kg up to 500 mg) orally, 6-hourly for 5 days2. For dosage adjustment in adults with kidney impairment, see cefalexin dosage adjustment cefalexin cefalexin cefalexin
OR if adherence to a 6-hourly regimen is unlikely in a child
1cefalexin 20 mg/kg up to 750 mg orally, 8-hourly for 5 days3. cefalexin
For patients with acute localised otitis externa who are at increased risk of MRSA infection, or who have had a severe (immediate or delayed)4 hypersensitivity reaction to penicillin, use:
1trimethoprim+sulfamethoxazole 160+800 mg (child 1 month or older: 4+20 mg/kg up to 160+800 mg) orally, 12-hourly for 5 days. For dosage adjustment in adults with kidney impairment, see trimethoprim+sulfamethoxazole dosage adjustment trimethoprim + sulfamethoxazole trimethoprim+sulfamethoxazole trimethoprim+sulfamethoxazole
OR
2clindamycin 450 mg (child: 10 mg/kg up to 450 mg) orally, 8-hourly for 5 days5. clindamycin clindamycin clindamycin
Advise patients to return for review after 3 to 5 days if symptoms are not improving or earlier if symptoms worsen; systemic antibiotic therapy is usually curative, though surgical drainage may also be required.