Excerpt from Gram-Negative Toe Web Infection

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Background

Gram-negative interweb foot impetigo is a relatively common and troubling disorder.¹ The infection is commonly associated with the use of closed-toe or tight-fitting shoes and in individuals in whom strong physical exertion plays an important role in athletic, occupational, or recreational activities.

Gram-negative mixed bacterial infection with organisms, such as Moraxella, Alcaligenes, Acinetobacter, Pseudomonas, Proteus, and Erwinia species, may represent a mild secondary infection of tinea pedis. Over time, in the setting of moisture and maceration, multiple fungal and bacterial organisms may proliferate.² The process may progress to advanced stages of gram-negative infection with sepsis.

The following Medscape CME courses may be of interest:

• Manifestations and Management of Resistant Gram-Negative Infections—A Case-based Approach (Slides with Audio)
• The Epidemiology and Impact of Rising Resistance Among Gram-Negative Bacilli (Slides with Transcript)
• Tools for Change: Stewardship and Newer Antimicrobial Agents to Manage Resistant Gram-Negative Bacilli (Slides with Transcript)
• Introduction: Resistant Gram-Negative Bacilli—Assessing Perceptions (Slides with Transcript)
• Resistant Gram-Negative Bacilli: A Neglected Healthcare Crisis? (Slides with Audio)

Pathophysiology

Typically, the interweb space is colonized by polymicrobial flora. Initially, a dermatophyte infection at this site may damage the stratum corneum and produce natural substances with antibiotic properties that alter the composition of the resident bacterial flora, encouraging the proliferation of antibiotic-resistant strains.³

Gram-negative bacteria may resist the antibacterial agents and many of the commonly used therapeutic agents. In other cases, marked hyperhidrosis with cutaneous maceration, often seen in people who enjoy vigorous athletic endeavors, may predispose individuals to gram-negative bacterial toe web infection. Pseudomonas aeruginosa, often together with other gram-negative bacteria, is the most common etiologic agent.¹

The toe web space provides a hospitable niche for gram-negative microorganisms; infection can quickly progress from mild overgrowth of resident bacteria to an advanced, severe, gram-negative infection. Lesions that affect the interdigital spaces can occasionally extend to the planta and the backs of the toes. The most frequent complaint of patients is burning and pain, and, in severe infection, problems with walking are noted.

Gram-negative bacteria gain access to the bloodstream from foci of tissue infection or possibly from heavy colonization. Trauma, tinea pedis, or depressed host resistance, as in diabetes mellitus or HIV disease, may also predispose individuals to the infection.

Frequency

United States

Few data are available on the frequency of gram-negative toe web infections.

International

A limited number of cases have been reported.

Mortality/Morbidity

This disorder can rarely progress to a life-threatening situation. Occasionally, in advanced severe cases, certain microorganisms (eg, P aeruginosa) can cause therapeutic problems in relation to antibiotic resistance and a risk of potential lethal complications. If septicemia occurs, especially in a patient who is immunocompromised, the condition may produce shock and death.

Acute bacterial cellulitis is a potentially serious, often recurrent infection. Risk factors for acute bacterial cellulitis in hospitalized patients were found to include the presence of sites of pathogen entry on toe webs.⁴ Improved awareness and management of toe web intertrigo, which may harbor bacterial pathogens, may reduce the prevalence of cellulitis.⁵

Race

Gram-negative toe web infection can affect any race.

Sex

Men appear to be more frequently affected, with a male-to-female ratio of 4:1 reported in one study.¹

Age

Gram-negative toe web infection affects young and elderly persons. In one series, patients were reported to be aged 1-74 years. The disorder rarely involves infants or children.

Please click here to view the full topic text: Gram-Negative Toe Web Infection