Diagnosis: Tinea pedis, interdigital type
A 35-year-old male marathon runner presents with a 2-week history of itchy, macerated toe-web spaces. Examination reveals erythema, scaling, and fissuring between the third and fourth toes, consistent with a fungal infection. This case highlights the importance of recognizing common dermatophyte infections in athletes.
A 35-year-old male marathon runner presents with a 2-week history of pruritic, macerated toe-web spaces. He reports discomfort while running and has noticed a foul odor. On examination, there is erythema and scaling with fissuring between the third and fourth toes, and mild keratinization of the surrounding skin.Location: Interdigital spaces, particularly between the third and fourth toes.Appearance: Erythematous, macerated, and scaly lesions.Symptoms: Intense itching and burning sensation.Odor: Foul smell noted by the patient.History of activity: Increased running frequency and duration over the past month.
The patient reports that the itching began after he increased his training regimen for an upcoming marathon. He has a history of similar episodes but has not sought treatment previously. He typically wears synthetic running shoes and moisture-wicking socks. There is no significant past medical history, and he denies any known allergies. He shares a home with two roommates who are healthy and active.Onset: Symptoms started approximately two weeks prior to presentation.Triggers: Increased training intensity and duration.Prior treatments: None; previously self-treated with over-the-counter antifungal powders.Social history: Active lifestyle; participates in group runs and visits public gyms.Exposure history: No known exposure to infected individuals.
Acute / First-Line ManagementTopical antifungals: Terbinafine 1% cream applied twice daily for 1-2 weeks or clotrimazole 1% cream applied twice daily for 2-4 weeks.Drying agents: Use of antifungal powders containing miconazole or tolnaftate may help manage moisture.Hygiene measures: Advise daily washing and thorough drying of feet, particularly between toes.Workup and Diagnostic ConfirmationPotassium hydroxide (KOH) preparation: Microscopic examination of skin scrapings can confirm the presence of fungal hyphae or spores.Culture: Fungal culture may be considered if diagnosis is uncertain or if the condition does not respond to initial treatment.Long-Term ManagementPreventive strategies: Advise wearing breathable footwear and moisture-wicking socks to reduce sweat accumulation.Regular foot inspections: Encourage routine self-examinations to catch recurrences early.Education: Discuss the importance of foot hygiene, particularly in athletes.
Contact Dermatitis: May present with similar itching and erythema, but typically has a more localized distribution and history of exposure to irritants or allergens.Psoriasis: Can affect the feet, but usually has a more chronic course, with well-defined plaques and silvery scaling.Intertrigo: Inflammatory condition due to friction and moisture, often presents with erythema and maceration but typically occurs in skin folds.Dyshidrotic Eczema: Characterized by vesicular lesions on palms and soles, with intense itching but less likely to present in toe-web spaces.Bacterial Infection: Secondary infection can occur in macerated areas, often presenting with pain, purulence, and systemic symptoms.Onychomycosis: Fungal infection of the nails can coexist but would primarily involve the nail plate rather than toe-web spaces.Candidiasis: Can cause similar symptoms, particularly in moist areas, but often presents with satellite lesions and is more common in immunocompromised individuals.Scabies: Typically presents with intense itching and burrows, but is more generalized and not confined to the feet.
High-Yield PearlsDiagnosis: Tinea pedis is the most common dermatophyte infection of the foot and often presents with itching and scaling in the toe-web spaces.Risk factors: Increased moisture and heat from physical activities, especially in athletes, predispose to fungal infections.Topical therapy: First-line treatment includes topical antifungals such as terbinafine and clotrimazole; oral therapy is reserved for extensive or refractory cases.Prevention: Encourage proper foot hygiene, including drying the feet and using antifungal powders to reduce recurrence.Diagnosis confirmation: KOH preparation is a quick and effective method for confirming fungal infections.Recognizing the signs of tinea pedis early can prevent complications and improve quality of life for athletes.
Tags: tinea pedis, dermatophyte, runner