Antibiotics for Foot Infections
Foot infections range from a mildly angry-looking toe after a bad pedicure to spreading cellulitis that needs same-day treatment. The right antibiotic depends on where the infection sits, what organism is likely behind it and whether you have conditions such as diabetes that slow healing. Here at the Achilles Centre we work alongside GPs to manage infected nails, post-surgical wounds and chronic foot ulcers. This page covers what you can expect from antibiotic treatment and when to act quickly.
Common types of foot infection
Paronychia (infection of the skin fold beside or beneath a nail) is the one we see most often in clinic. It usually follows an ingrown toenail, overzealous cuticle trimming or a small cut. Staphylococcus aureus is the typical culprit. Mild cases respond to warm salt soaks and topical antiseptic, but once pus collects or redness spreads beyond the nail fold an oral antibiotic is needed.
Cellulitis is a spreading area of redness, warmth and swelling, often on the dorsum of the foot or lower leg. It can develop from any break in the skin: a blister, cracked heel, insect bite or surgical wound. Group A Streptococcus and S. aureus are the usual organisms. Cellulitis moves fast: a patch of redness that doubles in size over a few hours warrants urgent medical review.
Diabetic foot ulcers carry the highest risk. Reduced sensation means the patient may not feel the injury. Poor circulation slows immune response. Infections in diabetic feet are often polymicrobial (a mix of Gram-positive cocci, Gram-negative rods and sometimes anaerobes) which complicates antibiotic selection.
First-line antibiotics in the UK
Flucloxacillin 500 mg four times daily is the standard choice for straightforward skin and soft-tissue infections caused by staphylococci. NICE Clinical Knowledge Summaries list it as first-line for cellulitis and wound infections where MRSA is not suspected. A typical course runs for five to seven days.
Co-amoxiclav (amoxicillin plus clavulanic acid, marketed as Augmentin) covers a broader range including some anaerobes. GPs prescribe it when infection is deeper, involves a bite wound or when the patient has diabetes and polymicrobial infection is likely. The standard adult dose is 625 mg three times daily.
Clarithromycin or erythromycin serve as alternatives for patients with a penicillin allergy. Trimethoprim may be added if a Gram-negative organism is suspected. For severe or rapidly spreading cellulitis, hospital admission and intravenous antibiotics (typically flucloxacillin plus benzylpenicillin) are the standard pathway.
Matching the antibiotic to the infection
The table below outlines common pairings. Your GP may adjust the choice based on local resistance data or culture results.
These are examples of typical regimens. Your GP will determine the appropriate antibiotic and dose based on culture results, your medical history and local resistance patterns.
| Infection type | Likely organisms | First-line antibiotic | Alternative | Usual course |
|---|---|---|---|---|
| Paronychia (mild-moderate) | S. aureus | Flucloxacillin 500 mg QDS | Clarithromycin 500 mg BD | 5-7 days |
| Cellulitis | Strep A, S. aureus | Flucloxacillin 1 g QDS | Co-amoxiclav 625 mg TDS | 7-14 days |
| Infected ingrown toenail | S. aureus, mixed | Flucloxacillin 500 mg QDS | Co-amoxiclav 625 mg TDS | 5-7 days |
| Diabetic foot ulcer (mild) | Polymicrobial | Co-amoxiclav 625 mg TDS | Doxycycline + metronidazole | 7-14 days |
| Post-surgical wound | S. aureus, Strep | Flucloxacillin 500 mg QDS | Cefalexin 500 mg TDS | 5-7 days |
Topical antibiotics and antiseptics
Fusidic acid cream (2%) is widely used in the UK for localised skin infections around wounds and nail folds. It works well against staphylococci but resistance is rising. The British Association of Dermatologists recommends limiting courses to ten days and reserving it for confirmed superficial infections.
Mupirocin ointment is an alternative, particularly when MRSA is a concern. For general wound cleaning, povidone-iodine solution or medical-grade manuka honey dressings offer antimicrobial activity without contributing to antibiotic resistance. We use these regularly in clinic after nail surgery and during ulcer management.
Antibiotics after nail surgery
Routine prophylactic antibiotics are not recommended after straightforward nail avulsion. A 2017 Cochrane review found no significant benefit in prescribing antibiotics after ingrown toenail procedures in healthy patients. Good wound care (daily saline irrigation, dry dressings, elevation) is more important than a prescription.
Antibiotics become necessary if the surgical site shows signs of spreading infection: increasing redness beyond the wound margins, purulent discharge, fever or red streaking up the foot. Contact your podiatrist or GP if these develop. Do not wait for a scheduled follow-up appointment.
Is the antibiotic working?
Draw around the edge of any redness with a ballpoint pen and note the date. This gives you and your clinician an objective measure of whether the infection is responding. If the boundary expands despite 48 hours of oral antibiotics, the antibiotic may need changing or you may need hospital assessment.
Finish the full course even if symptoms improve after two or three days. Stopping early contributes to resistance. Common side effects of penicillin-type antibiotics include nausea, diarrhoea and skin rash. A widespread rash or difficulty breathing after a dose is a medical emergency. Call 999.
Preventing foot infections
Keep small wounds clean and covered. Dry feet thoroughly after washing, especially between the toes. Avoid walking barefoot in communal areas. If you have diabetes, inspect your feet every day. A pocket mirror helps check the soles. Do not attempt bathroom surgery on ingrown nails; a podiatrist can remove the offending nail edge safely under local anaesthetic.
If you suspect a foot infection, contact your GP or visit our podiatry clinic (/services/podiatry/) for wound assessment.
Further reading
Recovering from nail surgery? Our guide to pain relief after nail surgery (/health-info/pain-after-nail-surgery/) covers what to expect in the first weeks.
Diabetic patients with foot wounds should also read our diabetic foot care page (/health-info/diabetic-foot-care/) for daily inspection advice.
Book an appointment through our podiatry service (/services/podiatry/) for wound assessment and nail care.
Disclaimer
This information is for educational purposes only and does not replace individual medical advice. Always consult your podiatrist or GP before starting any medication. If you develop signs of severe infection (high fever, confusion, rapidly spreading redness) attend A&E or call 999 without delay.
Frequently Asked Questions
How do I know if my foot infection needs antibiotics?
Spreading redness, increasing pain, warmth, swelling or pus usually indicate a bacterial infection that will benefit from antibiotics. A single red spot around a cut that is not worsening may resolve with antiseptic and dressings alone. When in doubt, show it to your GP or podiatrist. Catching it at 24 hours is much simpler than at 72.
Can I buy antibiotics for a foot infection over the counter?
Oral antibiotics are prescription-only in the UK. Topical fusidic acid cream is prescription-only in the UK. Your GP can prescribe it for localised skin infections. For anything beyond a small localised patch, you need a GP consultation.
Should I take antibiotics before podiatry treatment?
Prophylactic antibiotics are not routine for standard podiatry procedures. Patients with prosthetic heart valves, a history of endocarditis or severe immunosuppression should discuss cover with their cardiologist or GP in advance.
Sources
Medical Disclaimer
This page is for informational purposes only and does not constitute medical advice. Always consult a qualified healthcare professional before starting any treatment. The Achilles Centre is not responsible for the content of external websites linked from this page.
If you are experiencing a medical emergency, please call 999 or visit your nearest A&E department immediately.