Cutaneous adverse drug reactions make up 1% to 2% of all adverse drug reactions. From these adverse cutaneous drug reactions, 16% to 21% can be categorized as fixed drug reactions (FDR). Fixed drug reactions may show diverse morphology including but not limited to the following: dermatitis, Stevens-Johnson syndrome, urticaria, morbilliform exanthema, hypersensitivity syndrome, pigmentary changes, acute generalized exanthematous pustulosis, photosensitivity, and vasculitis. An FDR will occur at the same site because of repeated exposure to the offending agent, causing a corresponding immune reaction. There are many drugs that can cause an FDR, such as analgesics, antibiotics, muscle relaxants, and anticonvulsants. The antibiotic ciprofloxacin has been shown to be a cause of cutaneous adverse drug reactions; however, the fixed drug reaction bullous variant is rare. This case study was published to demonstrate a rare adverse side effect to a commonly used antibiotic in podiatric medicine.
Foot infections are a common and serious problem in persons with diabetes. Diabetic foot infections (DFIs) typically begin in a wound, most often a neuropathic ulceration. While all wounds are colonized with microorganisms, the presence of infection is defined by ≥2 classic findings of inflammation or purulence. Infections are then classified into mild (superficial and limited in size and depth), moderate (deeper or more extensive), or severe (accompanied by systemic signs or metabolic perturbations). This classification system, along with a vascular assessment, helps determine which patients should be hospitalized, which may require special imaging procedures or surgical interventions, and which will require amputation. Most DFIs are polymicrobial, with aerobic gram-positive cocci (GPC), and especially staphylococci, the most common causative organisms. Aerobic gram-negative bacilli are frequently copathogens in infections that are chronic or follow antibiotic treatment, and obligate anaerobes may be copathogens in ischemic or necrotic wounds.
Wounds without evidence of soft tissue or bone infection do not require antibiotic therapy. For infected wounds, obtain a post-debridement specimen (preferably of tissue) for aerobic and anaerobic culture. Empiric antibiotic therapy can be narrowly targeted at GPC in many acutely infected patients, but those at risk for infection with antibiotic-resistant organisms or with chronic, previously treated, or severe infections usually require broader spectrum regimens. Imaging is helpful in most DFIs; plain radiographs may be sufficient, but magnetic resonance imaging is far more sensitive and specific. Osteomyelitis occurs in many diabetic patients with a foot wound and can be difficult to diagnose (optimally defined by bone culture and histology) and treat (often requiring surgical debridement or resection, and/or prolonged antibiotic therapy). Most DFIs require some surgical intervention, ranging from minor (debridement) to major (resection, amputation). Wounds must also be properly dressed and off-loaded of pressure, and patients need regular follow-up. An ischemic foot may require revascularization, and some nonresponding patients may benefit from selected adjunctive measures. Employing multidisciplinary foot teams improves outcomes. Clinicians and healthcare organizations should attempt to monitor, and thereby improve, their outcomes and processes in caring for DFIs.
Pitted keratolysis is a bacterial infection that affects the plantar epidermis. Despite the condition being reported in many countries affecting both shod and unshod populations, there is little guidance for clinicians providing evidence or best practice guidelines on the management of this often stubborn infection.
Using a structured search of a range of databases, papers were identified that reported treatments tested on patients with the condition.
Most of the literature uncovered was generally of a low level, such as case-based reporting or small case series. Studies were focused mainly on the use of topical antibiotic agents, such as clindamycin, erythromycin, fusidic acid, and mupirocin, often in combination with other measures, such as hygiene advice and the use of antiperspirants. From the limited evidence available, the use of topical antibiotic agents shows some efficacy in the treatment of pitted keratolysis. However, there is currently no suggestion that oral antibiotic drug therapy alone is effective in managing the condition.
Currently, there is no consensus on the most effective approach to managing pitted keratolysis, but a combination of antimicrobial agents and adjunctive measures, such as antiperspirants, seems to demonstrate the most effective approach from the current literature available.
Excisional toenail matrixectomies are performed on the area of the foot that has been reported to have the highest concentration of resident microorganisms. A retrospective infection audit was performed to identify whether this unique area of the foot was more susceptible to postoperative infection.
A retrospective audit reviewing the postoperative infection rate over a 6-year period after excisional nail matrixectomy in 111 patients was undertaken.
The postoperative infection rate was found to be high (18.9%) relative to that of clean orthopedic foot and ankle surgery (0.5%–6.5%).
The unique concentration of resident microbes found in the nail folds could help explain the high rate of postoperative infections identified in this study. This may provide some argument to classify excisional nail matrixectomy as clean-contaminated surgery and, thus, warrant routine antibiotic prophylaxis. Further research is recommended to confirm the results of this study and to determine whether appropriately timed oral antibiotic prophylaxis will reduce the infection rate after nail surgery. (J Am Podiatr Med Assoc 101(4): 316–322, 2011)
Diabetic foot infection (DFI) is a serious, difficult-to-treat infection, especially when caused by methicillin-resistant Staphylococcus aureus (MRSA). Vancomycin has been the standard treatment for MRSA infection, but lower response rates in MRSA skin infections have been reported. This analysis assessed the outcome and safety of daptomycin therapy in patients with a DFI caused by MRSA.
Using the Cubicin Outcomes Registry and Experience and the European Cubicin Outcomes Registry and Experience (2006–2009), 79 patients with MRSA DFI were identified and included in this analysis.
In the 74 evaluable patients, daptomycin was administered at a median dose of 4.8 mg/kg primarily every 24 hours (85.1%) and for a median of 15.0 days. Overall, 77.0% of the patients (57 of 74) received initial therapy with activity against MRSA; however, of patients receiving daptomycin as second-line therapy (n = 31), only 45.2% were treated with an antibiotic agent active against MRSA. The overall clinical success and treatment failure rates were 89.2% and 10.8%, respectively. Success with daptomycin therapy was higher in patients who had surgery and in those whose initial therapy was daptomycin. Eleven patients had 14 adverse events, two of which were possibly related to daptomycin use and led to discontinuation.
In a large real-world cohort of patients with MRSA DFI, daptomycin therapy was shown to be generally well tolerated and effective. The use of an anti-MRSA antibiotic agent should be considered when implementing first-line antibiotic drug therapy for DFI in countries where MRSA is common to avoid inappropriate empirical treatment and potential negative effects on outcomes.
Staphylococcus pseudintermedius is an emerging zoonotic pathogen that is very similar to human Staphylococcus pathogens, particularly multidrug-resistant Staphylococcus aureus. Recent reports have indicated that S pseudintermedius is easily transmitted between pets (mainly dogs) and owners because of these similarities. Although this pathogen has been associated with diabetic foot infections, it has not yet been described in the podiatric medical literature. In this case report, we present a diabetic foot infection in a 61-year-old man that was refractory to multiple rounds of antibiotic drug therapy. Deep wound cultures eventually grew S pseudintermedius, which was the first known case of this pathogen reported in our hospital system.
Therapeutic Options for Diabetic Foot Infections
A Review with an Emphasis on Tissue Penetration Characteristics
Foot complications are common in diabetic patients; foot ulcers are among the more serious consequences. These ulcers frequently become infected, and if not treated promptly and appropriately, diabetic foot infections can lead to septic gangrene and amputation. Foot infections may be classified as mild, moderate, or severe; this largely determines the approach to therapy. Staphylococcus aureus is the most common pathogen in these infections, and the increasing incidence of methicillin-resistant S aureus during the past two decades has further complicated antibiotic treatment. Chronic infections are often polymicrobial. Physiologic changes, and local and systemic inflammation, can affect the plasma and tissue pharmacokinetics of antimicrobial agents in diabetic patients, leading to impaired target-site penetration. Knowledge of the serum and tissue concentrations of antibiotics in diabetic patients is, therefore, important for choosing the optimal drug and dose. This article reviews the commonly used therapeutic options for treatment, including many newer antibiotics developed to target multidrug-resistant gram-positive bacteria, and includes available data relating specifically to the tissue penetration of these agents. (J Am Podiatr Med Assoc 100(1): 52–63, 2010)
Background: After partial bone resection for osteomyelitis there is a high rate of osteomyelitis occurrence in the remaining bone due to adherent bacterial biofilm, dysvascular infected spongiosum bone, and absence of a surgical technique that can prevent osteomyelitis developing in the remaining bone.
Methods: Presented is a surgical procedure using a dicalcium phosphate bone void filler putty with antibiotics placed into the remaining bone to prevent the development of osteomyelitis, therefore preventing amputation.
Results: This procedure has an osteomyelitis eradication rate of 94.8% and also decreases the rate of lower-extremity amputations.
Conclusions: This procedure provides a single stage surgical technique for infected open bone defects decreasing the previously reported high osteomyelitis reoccurrence rate of 57.1% to 5.2%.
Below-the-knee amputation (BKA) can be a detrimental outcome of diabetic foot osteomyelitis (DFO). Ideal treatment of DFO is controversial, but studies suggest minor amputation reduces the risk of BKA. We evaluated risk factors for BKA after minor amputation for DFO.
This is a retrospective cohort of patients discharged from Denver Health Medical Center from February 1, 2012, through December 31, 2014. Patients who underwent minor amputation for diagnosis of DFO were eligible for inclusion. The outcome evaluated was BKA in the 6 months after minor amputation.
Of 153 episodes with DFO that met the study criteria, 11 (7%) had BKA. Failure to heal surgical incision at 3 months (P < .001) and transmetatarsal amputation (P = .009) were associated with BKA in the 6 months after minor amputation. Peripheral vascular disease was associated with failure to heal but not with BKA (P = .009). Severe infection, bacteremia, hemoglobin A1c, and positive histopathologic margins of bone and soft tissue were not associated with BKA. The median antibiotic duration was 42 days for positive histopathologic bone resection margin (interquartile range, 32–47 days) and 16 days for negative margin (interquartile range, 8–29 days). Longer duration of antibiotics was not associated with lower risk of BKA.
Patients who fail to heal amputation sites in 3 months or who have transmetatarsal amputation are at increased risk for BKA. Future studies should evaluate the impact of aggressive wound care or whether failure to heal is a marker of another variable.
The purpose of this article is to familiarize physicians with the risks of prescribing trimethoprim/sulfamethoxazole (TMP/SMX) for patients who have kidney or cardiac pathology, have hyperkalemia, or take other interacting medications. Although TMP/SMX is a drug that is frequently used to treat skin and soft-tissue infections of the leg and foot, particularly if methicillin-resistant Staphylococcus aureus is identified, it is not an innocuous antibiotic. Literature documenting the many adverse effects of TMP/SMX is reviewed. A case history is presented illustrating the association of TMP/SMX with the development of a life-threatening situation. Ways of avoiding these adverse events are discussed, and the use of safer antibiotics is recommended.