Is a nitrous oxide (N2O) foot bath effective for treating fungal infections of the foot, such as athlete's foot?

Nitrous Oxide Foot Bath for Fungal Infections

Do not use nitrous oxide (N2O) foot baths for treating fungal infections of the foot—there is no evidence supporting this intervention, and established topical antifungal agents have proven efficacy.

Evidence-Based Treatment Recommendations

For Athlete's Foot (Tinea Pedis)

The established treatments for fungal foot infections are topical antifungal agents, not nitrous oxide:

First-line topical therapies include:

• Allylamines (terbinafine, naftifine) demonstrate superior efficacy with treatment failure rates significantly lower than placebo (RR 0.33,95% CI 0.24-0.44) and are more effective than azoles (RR 0.63,95% CI 0.42-0.94) 1
• Azoles (clotrimazole, miconazole, bifonazole) also show strong efficacy with treatment failure rates of RR 0.30 (95% CI 0.20-0.45) compared to placebo 1
• Tolnaftate demonstrates excellent results with RR 0.19 (95% CI 0.08-0.44) for treatment failure 1

For Fungal Nail Infections (Onychomycosis)

Systemic therapy is preferred:

• Terbinafine and itraconazole are first-line treatments for dermatophyte onychomycosis 2
• Itraconazole can be given as 200 mg daily for 12 weeks continuously, or as pulse therapy at 400 mg daily for 1 week per month (three pulses for toenails) 2

Topical options for nails:

• Topical ciclopiroxolamine and amorolfine may be used but require prolonged application (at least 1 year) with generally poor cure rates 1

Why Nitrous Oxide Is Not Recommended

Absence of Evidence

• No clinical trials, guidelines, or established protocols exist for nitrous oxide foot baths in treating fungal infections
• Nitrous oxide is an anesthetic gas without documented antifungal properties in this application
• All major dermatology guidelines (British Association of Dermatologists, IWGDF) make no mention of nitrous oxide for fungal treatment 2

Novel Therapies Require Evidence

The British Association of Dermatologists explicitly states that newer devices and novel therapies cannot be recommended without adequate evidence 2. Even photodynamic therapy and various laser treatments, which have some preliminary data, cannot currently be recommended due to insufficient evidence 2.

Essential Adjunctive Measures

Beyond antifungal medication, prevention of reinfection is critical:

Hygiene and environmental control:

• Treat pre-ulcerative signs including fungal infections promptly with appropriate antifungal treatment 2
• Apply antifungal powders (miconazole, clotrimazole, tolnaftate) in shoes and on feet 2
• Wear protective footwear in communal areas; avoid walking barefoot 2, 3
• Keep feet dry, wear absorbent cotton socks, and change daily 3, 4
• Discard old contaminated footwear or treat with naphthalene mothballs in sealed plastic bags for minimum 3 days 2

Treatment of all infected household members simultaneously is essential to prevent reinfection 2.

Clinical Pitfalls to Avoid

• Do not pursue unproven therapies when evidence-based treatments exist with documented efficacy
• Do not delay appropriate antifungal treatment while attempting experimental interventions
• Ensure proper diagnosis with mycological confirmation before treatment when possible 2
• Address underlying conditions (diabetes, peripheral vascular disease) that may complicate fungal infections 2