From the Guidelines
Yes, you can have both a fungal and bacterial infection in a toe simultaneously, known as a polymicrobial infection. This condition occurs when different types of microorganisms infect the same area, and treatment typically requires addressing both infections with appropriate medications. According to the most recent and highest quality study, 1, most diabetic foot infections (DFIs) are polymicrobial, with aerobic gram-positive cocci (GPC), and especially staphylococci, being the most common causative organisms.
Key Considerations
- The bacterial component might require antibiotics like cephalexin (500mg four times daily for 7-14 days) or clindamycin (300mg four times daily for 7-14 days), depending on the specific bacteria involved, as suggested by 1.
- For fungal components, antifungal medications like terbinafine (250mg daily for 6-12 weeks) or topical solutions such as ciclopirox or amorolfine may be prescribed, as mentioned in 1.
- Proper diagnosis is crucial since the symptoms of mixed infections can be confusing—redness, swelling, and pain might suggest bacterial infection, while discoloration and thickening of the nail might indicate fungal involvement.
- A healthcare provider may need to take cultures to identify the specific pathogens before determining the appropriate treatment regimen, as recommended by 1 and 1.
Important Factors
- These dual infections often occur in people with compromised immune systems, diabetes, or after toe injuries that create entry points for microorganisms.
- It's essential to complete the full course of all prescribed medications even if symptoms improve earlier.
- The study by 1 emphasizes the importance of a multidisciplinary approach to managing DFIs, including proper wound care, dressing, and off-loading of pressure, as well as regular follow-up.
From the Research
Fungal and Bacterial Infections of the Toe
- Fungal infections of the toe, also known as onychomycosis, are most frequently caused by dermatophytes, primarily Trichophyton rubrum 2.
- Bacterial infections of the nails are caused by gram-negative bacteria, usually Pseudomonas aeruginosa, but also gram-positive bacteria like Staphylococcus aureus 2.
- It is possible to have a fungal infection in a toe altogether with a bacterial infection, as both types of infections can coexist in the same area 2, 3.
Treatment of Fungal and Bacterial Infections
- Treatment of onychomycosis includes application of topical antifungal agents, such as amorolfine and ciclopirox, and oral treatment using terbinafine, fluconazole, or itraconazole 2, 4.
- Bacterial infections are treated topically with antiseptic agents, such as octenidine, and in some cases with topical antibiotics, such as nadifloxacin and gentamicin 2.
- Pseudomonas infections of the nail organ are treated with ciprofloxacin, while other bacteria are treated according to the results of culture and sensitivity testing 2.
Risk Factors and Complications
- Interdigital tinea, occlusion, and humidity are predisposing factors for gram-negative bacterial toe web infection (GNBTWI) 3.
- History of self-medication with antifungals, antibiotics, and glucocorticosteroids can also contribute to the development of GNBTWI 3.
- Autosensitization dermatitis and frequent recurrences are common complications of GNBTWI 3.