Impetigo is most commonly treated with topical mupirocin ointment, applied directly to the sores three times a day for up to five days. For mild cases with just a few patches, this prescription cream is usually all that’s needed. When impetigo is more widespread or doesn’t respond to topical treatment, oral antibiotics like cephalexin become the standard approach.
Topical Antibiotics for Mild Cases
When impetigo involves a small area of skin, a topical antibiotic is the go-to treatment. Mupirocin 2% ointment is the most widely prescribed option. You apply a small amount to the affected area three times daily, and if the sores aren’t improving within 3 to 5 days, your provider will likely reassess and consider switching treatments.
A newer option, ozenoxacin cream, was FDA-approved in 2017 for treating impetigo caused by staph or strep bacteria. It’s cleared for use in adults and children as young as 2 months old, which makes it a useful alternative when mupirocin isn’t a good fit. Before applying any topical antibiotic, gently washing the area with soap and water and removing loose crusts helps the medication reach the infection.
When Oral Antibiotics Are Needed
Oral antibiotics come into play when impetigo covers a larger area, involves multiple patches, or when topical treatment hasn’t worked. They’re also preferred for bullous impetigo, the type that produces large fluid-filled blisters rather than the classic honey-colored crusts.
Cephalexin is one of the most commonly prescribed oral options. It works against both staph and strep, the two bacteria responsible for impetigo. For children, the typical course runs 7 to 14 days, with dosing based on the child’s weight. Other oral antibiotics in the same family, like dicloxacillin, work similarly and may be chosen depending on your provider’s preference and local resistance patterns.
Treatment When MRSA Is Suspected
If impetigo isn’t responding to first-line antibiotics, or if MRSA (methicillin-resistant staph) is common in your area, the antibiotic choice shifts. Clindamycin is a frequent pick because it covers MRSA effectively. Trimethoprim-sulfamethoxazole is another option, though it has a notable limitation: it kills staph but doesn’t adequately treat strep. That matters because strep is one of the two main causes of impetigo, so your provider may need to add coverage or choose a different drug if strep is also a concern.
Tetracycline-class antibiotics can treat MRSA-related impetigo in older patients, but they’re not suitable for children under eight because they can permanently stain developing teeth. Your provider will typically send a wound culture when MRSA is suspected, then adjust the antibiotic once results come back showing exactly which drugs the bacteria respond to.
Why Treatment Sometimes Fails
Antibiotic resistance is a growing problem with impetigo. Both staph and strep have a tendency to develop resistance relatively quickly, and resistant strains are emerging faster than new treatments can replace older ones. If your impetigo isn’t improving after a few days of treatment, resistance is one possible explanation.
The other common reason for treatment failure is inconsistent use. Topical antibiotics need to be applied consistently three times a day, and oral courses need to be finished completely, even after the skin starts looking better. Stopping early gives surviving bacteria a chance to rebound and potentially develop resistance. For children who’ve had repeated episodes, the frustration of ongoing treatment can also affect how consistently the medication gets used.
How Quickly Antibiotics Work
Most people start feeling better within a few days of starting treatment. The sores stop spreading first, then gradually dry out and heal. Complete healing takes longer, sometimes a couple of weeks, but impetigo rarely leaves scars.
One of the most practical concerns, especially for parents, is when a child can go back to school or daycare. The CDC says people with impetigo can return to school or work at least 12 hours after starting antibiotic treatment. The American Academy of Pediatrics uses the same 12-hour guideline for group A strep infections, with the added condition that the child should appear well. In certain situations, like outbreaks at a daycare or infections in healthcare workers, a 24-hour waiting period is recommended instead.
Without any treatment at all, impetigo can clear on its own in a few weeks. But antibiotics speed healing significantly, reduce the risk of spreading the infection to others, and lower the small but real chance of complications like deeper skin infections.
Topical vs. Oral: How Your Provider Decides
The decision between a topical cream and oral pills comes down to a few factors. If you have fewer than five small lesions in one area, topical mupirocin or ozenoxacin is typically sufficient and avoids the side effects that can come with oral antibiotics, like stomach upset or diarrhea. Once the infection is more widespread, involves the mouth or nose area extensively, or has already failed topical treatment, oral antibiotics are the more reliable choice.
Children get impetigo far more often than adults, and both forms of treatment work well in pediatric patients. For very young children, ozenoxacin is approved down to 2 months of age, while mupirocin has a long track record of safe use in kids. Oral cephalexin dosing for children is calculated by weight, so your pharmacist will adjust the amount based on your child’s size. The course length is the same 7 to 14 days regardless of age.