Module 3: Common Foot Conditions & Diseases
Module 3 of 10 · Lesson 1 of 5
Module 3 · Lesson 1
Fungal Infections of the Foot
Learning Objectives
By the end of this lesson, the learner will be able to:
- Differentiate the clinical presentation of tinea pedis (athlete's foot) and onychomycosis (fungal nail infection).
- Identify risk factors and patient populations most susceptible to fungal foot infections.
- Conduct a structured nursing assessment using a Look, Feel, Ask framework.
- Describe evidence-based treatment options and the role of nursing in prevention and patient education.
Fungal infections are among the most common foot conditions nurses encounter — and among the most under-recognized. They thrive in warm, moist environments, spread easily, and frequently travel from skin to nails. Recognizing the difference between tinea pedis and onychomycosis, knowing when to refer, and teaching effective prevention are core skills in foot care nursing.
Who's at Risk?
Fungal foot infections affect anyone, but certain patients are at substantially higher risk:
Higher-Risk Populations
Diabetes & immunocompromise
Hyperhidrosis (excessive sweating)
Peripheral vascular disease
Communal showers, gyms, pools
Tinea Pedis vs. Onychomycosis
The two main fungal infections of the foot frequently coexist — onychomycosis often develops from untreated tinea pedis. Knowing how each presents lets nurses identify both quickly.
Side-by-Side Comparison
What it is
Dermatophyte infection of the skin of the foot, typically the interdigital web spaces.
Where
Between toes (most common), soles, sides of feet.
Symptoms
- Itching
- Burning
- Peeling skin
- Maceration
- Scaling
- Vesicles (acute)
Onset
Usually acute or subacute; symptomatic.
What it is
Dermatophyte (most common), yeast, or mold infection of the nail unit.
Where
Toenails (great toenail most often); often spreads from existing tinea pedis.
Symptoms
- Thickening
- Yellow-brown color
- Brittleness
- Subungual debris
- Onycholysis
- Foul odor (advanced)
Onset
Slowly progressive over months to years; often painless.
Clinical Connection
If you find one, look for the other. Patients with onychomycosis frequently have undiagnosed tinea pedis, and treating the nail without addressing the skin almost guarantees recurrence.
Nursing Assessment: Look, Feel, Ask
A structured three-step approach captures most fungal foot findings quickly.
Step 1 · Look
Visual inspection
- Examine each interdigital web space for peeling, redness, maceration, and fissures
- Inspect the soles and sides of the feet for scaling, vesicles, or hyperkeratosis
- Examine each toenail: color, thickness, surface texture, and any subungual debris
- Note the great toenail particularly — it's the most common site for onychomycosis
Step 2 · Feel
Tactile assessment
- Note skin moisture: persistent dampness, particularly between toes, supports fungal etiology
- Assess for pain or tenderness — most fungal infections are mildly itchy or asymptomatic; significant pain or warmth raises concern for secondary bacterial infection
- Check temperature: increased warmth at a site of skin breakdown warrants closer evaluation
Step 3 · Ask
Focused history
- Footwear habits: closed shoes worn for long periods, materials, ventilation
- Hygiene: frequency of sock changes, foot drying after bathing, drying between toes
- Environmental exposure: gym showers, public pools, shared bathrooms
- Prior episodes and treatments tried; duration of symptoms
- Comorbidities: diabetes, immunocompromise, vascular disease
Refer when…
Findings beyond simple tinea pedis or limited onychomycosis warrant escalation: signs of bacterial superinfection (significant erythema, warmth, drainage, pain), cellulitis, non-healing breaks in the skin, or any fungal infection in a patient with diabetes or peripheral vascular disease. The nursing role here is recognition and timely handoff, not extended trial-and-error treatment.
Treatment Pathways
Treatment differs significantly between skin and nail infections — both in agent and duration.
Confirmed fungal infection of the foot
🦠 Skin (tinea pedis)
First-line therapy
- Topical antifungal (e.g., terbinafine, clotrimazole) applied as directed
- Keep feet clean and dry; change socks daily
- Avoid going barefoot in communal areas
- Treat both feet even if symptoms appear unilateral
Typical duration: 1–4 weeks of topical therapy
💅 Nail (onychomycosis)
Stepped therapy (provider-directed)
- Confirm diagnosis clinically and, when indicated, with KOH prep, fungal culture, or PCR
- Topical agents (ciclopirox, efinaconazole) for limited or mild disease
- Oral antifungals (terbinafine, itraconazole, fluconazole) for moderate to severe disease, when not contraindicated
- Conservative debridement of thickened nails to reduce pressure and improve drug penetration
- Treat any concurrent tinea pedis to prevent reinfection
Typical duration: 6–12 weeks oral therapy; 6+ months for full visible nail clearance
Oral antifungals require provider oversight
Oral antifungals can affect liver function and interact with other medications. Baseline liver function testing and a current medication review are standard before starting oral therapy. Nurses are well-positioned to initiate this conversation, but the decision and prescribing belong to the patient's provider.
Prevention & Patient Education
Recurrence is common. Patient education is the single most powerful nursing intervention.
Patient Teaching
Six daily habits that prevent fungal foot infections
Wash & dry daily
Especially between the toes
Moisture-wicking socks
Change at least daily
Rotate shoes
Allow 24h to dry between wears
Never barefoot
In showers, pools, locker rooms
Antifungal powder
In shoes for high-risk patients
Trim nails properly
Don't share clippers
Patient Teaching Moment
A patient with diabetes presents with thickened, yellow great toenails and persistent maceration between the 4th and 5th toes on both feet. The nurse documents both findings, coordinates with the provider on whether oral antifungal therapy is appropriate (with liver function testing), and teaches the patient to dry between the toes carefully, rotate two pairs of shoes, and use antifungal powder daily — addressing the skin and the nails to prevent rapid recurrence.
Ready to check your understanding? Take the quick knowledge check for this lesson.
Educational Disclaimer
This lesson is provided for professional continuing education and informational purposes only. It is intended to support knowledge development in foot care nursing and does not constitute clinical advice, legal advice, or regulatory guidance.
This course content does not replace, supersede, or serve as a substitute for: the California Board of Registered Nursing (BRN) Nurse Practice Act and current BRN regulations (rn.ca.gov); California state laws and health codes governing nursing practice; county and local public health department requirements applicable to your practice setting; your facility's policies, protocols, and procedures; or your individual scope of practice as defined by your nursing license, credentials, and employer authorization.
Verify before practicing. Clinical guidelines, regulatory requirements, and scope-of-practice rules change over time. You are responsible for verifying all clinical information against current BRN regulations, California law, county requirements, and your facility's policies before applying any content from this course in practice. When in doubt, consult your supervisor, your facility's compliance team, or the California Board of Registered Nursing directly at rn.ca.gov.
References
- Lipner SR, Scher RK. Onychomycosis: Clinical overview and diagnosis. Journal of the American Academy of Dermatology. 2019;80(4):835–851.
- Lipner SR, Scher RK. Onychomycosis: Treatment and prevention of recurrence. Journal of the American Academy of Dermatology. 2019;80(4):853–867.
- Ilkit M, Durdu M. Tinea pedis: the etiology and global epidemiology of a common fungal infection. Critical Reviews in Microbiology. 2015;41(3):374–388.
- American Diabetes Association Professional Practice Committee. Standards of Care in Diabetes — 2024 (Section 12). Diabetes Care. 2024;47(Suppl 1).
- Habif TP. Clinical Dermatology: A Color Guide to Diagnosis and Therapy. 7th ed. Elsevier; 2021.
- Centers for Disease Control and Prevention. About Ringworm (Tinea). 2024.