Oral antibiotics (eg, dicloxacillin or cephalexin 250 to 500 mg 4 times a day [12.5 mg / kg 4 times a day for children] for 10 days) may be needed in patients who are immunocompromised, who have extensive or resistant impetigo lesions, or who have ecthyma. In penicillin-allergic patients, clindamycin 300 mg every 6 hours or erythromycin 250 mg every 6 hours may be used, but resistance to both antibiotics is an increasing problem.