Are We Overlooking Gram-Negative Toe Web Infections?

by Haroon Ahmad, MD 2025-01-01 00:00

PhysicianMedical

🔍 Key Finding Gram-negative bacterial toe web infection (GNTWI), most commonly caused by Pseudomonas aeruginosa, often presents with exudative, erythematous maceration in toe web spaces and can be challenging to treat due to antibiotic resistance and a lack of standardized treatment guidelines. Effective treatments often involve oral ciprofloxacin for moderate to severe cases, topical gentamicin for milder infections, and addressing underlying conditions like eczema or tinea pedis that may predispose to GNTWI.

🔬 Methodology Overview

Design: Narrative review.
Data Sources: PubMed database.
Selection Criteria: Articles published before August 31, 2022, related to “toe web infection”. Additional articles included from reference lists of relevant reviews. Non-English, non-full text, and duplicate articles excluded. Title and abstract screening for relevance.
Analysis Approach: Qualitative synthesis of findings from included studies.
Scope: Clinical presentation, epidemiology, promoting factors, etiology, diagnosis, and treatment of gram-negative toe web infections.

📊 Results

Epidemiology: GNTWI incidence is approximately 13.6 cases per year, with a male-to-female ratio of 4:1. It typically affects middle-aged adults (median age 51-52.5 years), but can occur in children and older adults (age range 10-94 years).
Clinical Presentation: GNTWI manifests as exudative, erythematous maceration in toe web spaces, often with malodorous discharge. It can present with vesicles, pustules, fissures, and a greenish discoloration (in Pseudomonas infections). Severe cases may involve cellulitis or erysipelas.
Risk Factors: Humid and occlusive environments (e.g., wet work conditions, occlusive footwear) promote GNTWI. Pre-existing skin conditions like eczema (present in 42-66% of recurrent GNTWI), psoriasis (11%), and fungal infections (tinea pedis, Candida) increase risk.
Etiology: Pseudomonas aeruginosa is the most common causative agent (46.4-84.5% of cases). Polymicrobial infections are frequent (93% in one study), with other Gram-negative bacteria ( E. coli, Proteus mirabilis) and occasionally Gram-positive bacteria and fungi also present.
Treatment: There are no established treatment guidelines. Topical antiseptics (e.g., acetic acid, amikacin) and antibiotics (e.g., gentamicin) are used in combination with systemic antibiotics, primarily oral ciprofloxacin (250-500 mg twice daily for 10-14 days), for moderate to severe cases.
Recurrence: Recurrence rates range from 7% to 53%. Managing underlying skin conditions (eczema, psoriasis, fungal infections) and reducing environmental risk factors are crucial for preventing recurrence.

💡 Clinical Impact GNTWI, though common, may be under-recognized and warrants further investigation into standardized treatment guidelines to improve patient outcomes and reduce recurrence, given its potential to cause significant pain and progress to severe infections like cellulitis. Clinicians should consider GNTWI in patients with macerated toe web spaces, particularly those with risk factors like humid environments, occlusive footwear, or pre-existing dermatologic conditions, and pursue bacterial and fungal cultures for diagnosis.

🤔 Limitations

Scarcity of epidemiological data on GNTWI, precluding accurate estimations of incidence and prevalence.
Risk of antibiotic resistance.
Lack of standardization of treatment methods.
Limited long-term follow-up data in available studies.
Concomitant dermatological conditions like eczema, psoriasis, and tinea pedis can complicate treatment and contribute to recurrence.
Multi-drug resistant Pseudomonas aeruginosa infections present additional management challenges.

✨ What It Means For You Doctors should be aware of GNTWI’s potential for misdiagnosis as other dermatological conditions (eczema, psoriasis, tinea pedis, pitted keratolysis) or even malignancy, and consider bacterial and fungal cultures for macerated toe web infections unresponsive to initial treatments. Management should address underlying conditions and patient education on mitigating risk factors (moisture, occlusion) is crucial for preventing recurrence, while topical or systemic antibiotics, often in combination, are used to treat active infections.

Reference Waterton KA, Lipner SR. Gram-Negative Toe Web Infections. Dermatol Pract Concept. 2024;14(1):e2024059. https://doi.org/10.5826/dpc.1401a59