A hospital audit reveals that 75% of patients receiving IV antibiotics for community-acquired pneumonia have not had renal function checked in the 48 hours prior to prescribing, and 40% of prescriptions do not document stop dates or review dates. The antimicrobial stewardship team proposes implementing mandatory electronic prescribing fields to address these gaps. Which of the following represents the most significant potential benefit of this intervention from a patient safety and antimicrobial stewardship perspective?
Q172
A 44-year-old woman with rheumatoid arthritis on methotrexate 15mg weekly and prednisolone 10mg daily presents with a 2-day history of a painful, rapidly expanding erythematous area on her right thigh. The area is warm, tender, has indistinct margins, and measures approximately 15cm × 10cm. There is associated oedema but no crepitus or bullae. Temperature is 38.7°C, HR 104/min, BP 118/76 mmHg, RR 18/min. Blood tests show WCC 16.8 × 10⁹/L, CRP 178 mg/L, lactate 1.8 mmol/L. Which of the following represents the most appropriate management plan?
Q173
A hospital trust antimicrobial stewardship committee is evaluating a new point-of-care C-reactive protein (CRP) testing device for use in primary care to guide antibiotic prescribing decisions for respiratory tract infections. Initial pilot data shows a 30% reduction in antibiotic prescribing rates. However, the device costs £15,000 per unit plus £3 per test. Which of the following parameters would be MOST important to evaluate when determining whether this intervention represents good antimicrobial stewardship practice from a healthcare system perspective?
Q174
A 37-year-old man who works as a fishmonger presents with a 5-day history of a violaceous, bullous lesion on his left hand that started after sustaining a minor cut while handling shellfish. The lesion has progressed rapidly with surrounding oedema and erythema extending to the wrist. He reports feeling systemically unwell with fever. He has a history of chronic liver disease secondary to alcohol excess. Blood cultures have been sent. What is the most likely causative organism and the most appropriate empirical antibiotic therapy?
Q175
A 49-year-old woman undergoes wide local excision of breast cancer with axillary lymph node clearance. She receives cefuroxime 1.5g IV as surgical prophylaxis at induction. Post-operatively, she remains apyrexial and well with normal inflammatory markers. The surgical team plans to prescribe 5 days of prophylactic oral co-amoxiclav citing the extent of axillary dissection. According to antimicrobial stewardship principles and evidence-based practice, what is the most appropriate course of action?
Q176
A hospital antimicrobial stewardship team reviews prescribing data for urinary tract infections in elderly patients. They identify that 60% of patients aged over 75 years with asymptomatic bacteriuria (positive urine culture without urinary symptoms) are receiving antibiotic treatment. The team implements an intervention targeting this practice. Which of the following would represent the most effective stewardship intervention to address this issue?
Q177
A 54-year-old man with morbid obesity (BMI 42 kg/m²) undergoes emergency laparotomy for perforated sigmoid diverticulitis. He receives appropriate intraoperative antibiotic prophylaxis with co-amoxiclav 1.2g IV. The operation lasts 4.5 hours. According to antimicrobial stewardship principles for surgical prophylaxis, which of the following represents best practice for intraoperative antibiotic administration?
Q178
A 28-year-old healthcare worker develops a paronychia following a needlestick injury while removing an IV cannula from a patient 4 days ago. She has increasing pain, erythema, and swelling around the right index fingernail with purulent discharge. There is no lymphangitis or systemic features. The source patient is known to have hepatitis B infection (HBsAg positive) but is HIV and hepatitis C negative. What is the most appropriate management of the paronychia?
Q179
A 66-year-old woman with type 2 diabetes and peripheral neuropathy presents with a painless ulcer on the plantar surface of her right foot present for 3 weeks. The ulcer is 3cm diameter, extends to tendon level, and has purulent discharge with surrounding erythema extending 4cm beyond the ulcer margin. There is crepitus on palpation. Temperature is 38.9°C, HR 108/min, BP 128/82 mmHg. X-ray shows soft tissue gas but no obvious bony involvement. What is the most appropriate immediate management?
Q180
A 33-year-old man who recently started attending a gym presents with multiple painful, erythematous pustules and small abscesses on his buttocks and thighs. He reports several gym members have had similar lesions. On examination, there are multiple follicular-based pustules with surrounding erythema, some with small fluctuant areas. Temperature is 37.5°C. What is the most likely causative organism and most appropriate initial management?
Common Infections UK Medical PG Practice Questions and MCQs
Question 171: A hospital audit reveals that 75% of patients receiving IV antibiotics for community-acquired pneumonia have not had renal function checked in the 48 hours prior to prescribing, and 40% of prescriptions do not document stop dates or review dates. The antimicrobial stewardship team proposes implementing mandatory electronic prescribing fields to address these gaps. Which of the following represents the most significant potential benefit of this intervention from a patient safety and antimicrobial stewardship perspective?
A. Improved documentation will reduce medicolegal risk for prescribing clinicians
B. Mandatory fields ensure appropriate dose adjustment and prompt review, reducing toxicity and unnecessary antibiotic duration (Correct Answer)
C. Electronic prescribing creates an audit trail for investigating prescribing errors retrospectively
D. Completion rates for mandatory fields provide data for clinician performance appraisal
E. Standardized prescribing reduces variation between departments and improves consistency
Explanation: ***Mandatory fields ensure appropriate dose adjustment and prompt review, reducing toxicity and unnecessary antibiotic duration***- The mandatory field for **renal function checks** directly facilitates **dose adjustment** for renally-excreted antibiotics, preventing **drug toxicity** and improving patient safety.- Mandatory **stop or review dates** are crucial for ensuring **timely discontinuation** or de-escalation of antibiotics, which directly combats **antimicrobial resistance** and optimizes therapy duration.*Improved documentation will reduce medicolegal risk for prescribing clinicians*- While better documentation offers **medicolegal protection**, this is a secondary benefit and not the primary driver for **antimicrobial stewardship** which focuses on clinical outcomes and public health.- The intervention aims to improve direct patient care and safety, rather than solely reducing **clinician liability**.*Electronic prescribing creates an audit trail for investigating prescribing errors retrospectively*- **Retrospective audit trails** provide data for system learning, but the core benefit of mandatory fields is **prospective error prevention** at the point of prescribing.- The intervention directly addresses the identified gaps by preventing inappropriate dosing and prolonged treatment *before* they occur.*Completion rates for mandatory fields provide data for clinician performance appraisal*- Using completion rates for **performance appraisal** is an administrative outcome, separate from the direct **patient safety** and **antimicrobial stewardship** benefits of the intervention itself.- The primary goal is improving actual patient care processes and outcomes, not merely tracking clinician compliance for evaluation.*Standardized prescribing reduces variation between departments and improves consistency*- While **standardization** is a goal, the most significant benefit here stems from the *specific content* of the mandatory fields, enforcing critical **safety checks** (renal dosing, duration).- The benefit is not just general consistency, but targeted improvement in safe and effective antibiotic prescribing practices.
Question 172: A 44-year-old woman with rheumatoid arthritis on methotrexate 15mg weekly and prednisolone 10mg daily presents with a 2-day history of a painful, rapidly expanding erythematous area on her right thigh. The area is warm, tender, has indistinct margins, and measures approximately 15cm × 10cm. There is associated oedema but no crepitus or bullae. Temperature is 38.7°C, HR 104/min, BP 118/76 mmHg, RR 18/min. Blood tests show WCC 16.8 × 10⁹/L, CRP 178 mg/L, lactate 1.8 mmol/L. Which of the following represents the most appropriate management plan?
A. Commence oral flucloxacillin 1g four times daily and review in 48 hours if not improving
B. Admit for IV flucloxacillin 2g four times daily and regular clinical review (Correct Answer)
C. Arrange urgent surgical review for necrotizing fasciitis and commence IV clindamycin and benzylpenicillin
D. Admit for IV vancomycin and piperacillin-tazobactam pending blood culture results
E. Admit for IV flucloxacillin and temporarily discontinue methotrexate and prednisolone
Explanation: ***Admit for IV flucloxacillin 2g four times daily and regular clinical review*** - This patient presents with **cellulitis** and **systemic inflammatory response syndrome (SIRS)** (fever, tachycardia, leukocytosis), and being **immunocompromised** (methotrexate and steroids) necessitates hospital admission for **intravenous antibiotics**. - **Flucloxacillin** is the appropriate **first-line empirical treatment** for suspected **streptococcal** and **staphylococcal** skin and soft tissue infections, the most common causes of cellulitis. *Commence oral flucloxacillin 1g four times daily and review in 48 hours if not improving* - **Oral antibiotics** are inappropriate in this case due to the presence of clear **systemic features** (fever 38.7°C, tachycardia, raised inflammatory markers) and the patient's **immunosuppressed status**. - Delaying hospital-level care for 48 hours in a patient with **SIRS** and rapidly expanding erythema increases the risk of **sepsis progression** and poor clinical outcomes. *Arrange urgent surgical review for necrotizing fasciitis and commence IV clindamycin and benzylpenicillin* - While a serious consideration, the absence of key features such as **crepitus**, **bullae**, skin necrosis, and a relatively normal **lactate** (1.8 mmol/L) makes **necrotizing fasciitis** less likely than simple cellulitis. - The pain is described as tender but not
Question 173: A hospital trust antimicrobial stewardship committee is evaluating a new point-of-care C-reactive protein (CRP) testing device for use in primary care to guide antibiotic prescribing decisions for respiratory tract infections. Initial pilot data shows a 30% reduction in antibiotic prescribing rates. However, the device costs £15,000 per unit plus £3 per test. Which of the following parameters would be MOST important to evaluate when determining whether this intervention represents good antimicrobial stewardship practice from a healthcare system perspective?
A. Comparison of antibiotic prescribing rates before and after intervention in pilot practices
B. Patient satisfaction scores regarding consultation length and shared decision-making
C. Cost-effectiveness analysis including prevented antibiotic courses, resistance reduction, and adverse events avoided (Correct Answer)
D. Sensitivity and specificity of CRP testing compared to clinical diagnosis for bacterial infections
E. Number of hospital admissions for respiratory infections in areas using the device
Explanation: ***Cost-effectiveness analysis including prevented antibiotic courses, resistance reduction, and adverse events avoided***
- A **cost-effectiveness analysis** is crucial for a **healthcare system perspective** as it evaluates if the device's significant cost is justified by the clinical and economic benefits of reduced antibiotic use.
- This analysis quantifies the **return on investment** by considering averted antibiotic courses, reduced **antimicrobial resistance**, and avoided adverse events like **C. difficile infection**.
*Comparison of antibiotic prescribing rates before and after intervention in pilot practices*
- While a **30% reduction** in prescribing is a positive indicator, this metric alone does not encompass the full **healthcare system impact** or cost-effectiveness of the intervention.
- It does not account for the **cost of the device** or the potential long-term savings associated with reduced resistance and avoided complications.
*Patient satisfaction scores regarding consultation length and shared decision-making*
- **Patient satisfaction** is an important aspect of quality care but is a secondary outcome in evaluating the primary objectives of **antimicrobial stewardship** from a system perspective.
- It does not directly assess the **economic viability** of the intervention or its direct impact on **public health challenges** like resistance.
*Sensitivity and specificity of CRP testing compared to clinical diagnosis for bacterial infections*
- These **diagnostic accuracy** parameters are essential for validating the device's technical reliability but do not address the broader **healthcare system implications** of its implementation.
- High accuracy is a prerequisite, but it doesn't quantify the **cost-benefit ratio** or the population-level reduction in **antimicrobial resistance**.
*Number of hospital admissions for respiratory infections in areas using the device*
- While relevant for **patient safety** and resource use, changes in hospital admissions might be too distal or multifactorial to be the *most* important direct measure of **primary care antimicrobial stewardship** success.
- This metric does not directly evaluate the **financial sustainability** or the specific impact on **antibiotic resistance** driven by primary care prescribing patterns.
Question 174: A 37-year-old man who works as a fishmonger presents with a 5-day history of a violaceous, bullous lesion on his left hand that started after sustaining a minor cut while handling shellfish. The lesion has progressed rapidly with surrounding oedema and erythema extending to the wrist. He reports feeling systemically unwell with fever. He has a history of chronic liver disease secondary to alcohol excess. Blood cultures have been sent. What is the most likely causative organism and the most appropriate empirical antibiotic therapy?
A. Staphylococcus aureus; flucloxacillin and doxycycline
B. Vibrio vulnificus; doxycycline and ceftriaxone (Correct Answer)
C. Erysipelothrix rhusiopathiae; benzylpenicillin alone
D. Aeromonas hydrophila; ciprofloxacin and metronidazole
E. Mycobacterium marinum; clarithromycin and rifampicin
Explanation: ***Vibrio vulnificus; doxycycline and ceftriaxone***
- The patient's history of **shellfish handling**, a **minor cut**, rapid progression of a **violaceous, bullous lesion**, **systemic illness (fever)**, and underlying **chronic liver disease** are classic features of severe *Vibrio vulnificus* infection.
- Empiric treatment for severe *Vibrio vulnificus* infection, especially in high-risk patients like those with liver disease, requires a combination of **doxycycline** and a **third-generation cephalosporin** (e.g., ceftriaxone) due to the rapid progression and high mortality.
*Staphylococcus aureus; flucloxacillin and doxycycline*
- While *S. aureus* can cause cellulitis and skin infections, it is less likely to produce rapidly spreading **hemorrhagic bullae** specifically linked to marine exposure and underlying liver disease.
- Doxycycline is not a first-line agent for typical *S. aureus* skin infections, and flucloxacillin alone would not adequately cover *Vibrio* if it were the cause.
*Erysipelothrix rhusiopathiae; benzylpenicillin alone*
- *Erysipelothrix rhusiopathiae* is associated with fish handling and causes **erysipeloid**, a localized, violaceous lesion, but it typically does **not cause systemic symptoms** or rapid bullous necrosis.
- This infection is generally milder and more localized, lacking the aggressive, life-threatening systemic features seen in this patient with chronic liver disease.
*Aeromonas hydrophila; ciprofloxacin and metronidazole*
- *Aeromonas hydrophila* infections are usually associated with **freshwater exposure** or contaminated soil, not typically saltwater shellfish or marine environments like *Vibrio*.
- While it can cause aggressive soft tissue infections, the specific epidemiological and clinical context (shellfish exposure, liver disease, bullous lesions) points more strongly to *Vibrio vulnificus*.
*Mycobacterium marinum; clarithromycin and rifampicin*
- *Mycobacterium marinum* causes **fish tank granuloma** or **swimming pool granuloma**, which presents as chronic, indolent nodular or ulcerative lesions, often with a sporotrichoid pattern of spread.
- This infection has a **subacute to chronic course** (weeks to months) and does not typically present as an **acute, rapidly progressing, systemic, bullous illness** within 5 days.
Question 175: A 49-year-old woman undergoes wide local excision of breast cancer with axillary lymph node clearance. She receives cefuroxime 1.5g IV as surgical prophylaxis at induction. Post-operatively, she remains apyrexial and well with normal inflammatory markers. The surgical team plans to prescribe 5 days of prophylactic oral co-amoxiclav citing the extent of axillary dissection. According to antimicrobial stewardship principles and evidence-based practice, what is the most appropriate course of action?
A. Agree with post-operative antibiotic prophylaxis for 5 days given the extent of surgery
B. Recommend extending to 7 days of antibiotics to cover until drain removal
C. Advise against post-operative antibiotics as single-dose prophylaxis is sufficient for clean surgery (Correct Answer)
D. Prescribe 3 days of antibiotics as a compromise between no antibiotics and 5 days
E. Recommend IV antibiotics for 24 hours post-operatively before switching to oral
Explanation: ***Advise against post-operative antibiotics as single-dose prophylaxis is sufficient for clean surgery***- Breast cancer surgery with axillary clearance is classified as **clean surgery**, for which a **single dose** of perioperative antibiotic prophylaxis (like the cefuroxime given) is sufficient according to evidence-based guidelines (e.g., NICE, WHO).- Continuing antibiotics post-operatively for clean surgery violates **antimicrobial stewardship principles** and increases risks such as **antimicrobial resistance**, **Clostridioides difficile infection**, and side effects without providing additional benefit.*Agree with post-operative antibiotic prophylaxis for 5 days given the extent of surgery*- The **extent of axillary dissection** in this context does not transform a clean surgical procedure into one requiring prolonged post-operative antibiotic prophylaxis.- Routine extended post-operative antibiotics for clean surgery do not reduce **surgical site infection** rates and promote antibiotic resistance, contravening **antimicrobial stewardship**.*Recommend extending to 7 days of antibiotics to cover until drain removal*- The **presence of surgical drains** alone is not an indication for extending prophylactic antibiotics beyond the initial perioperative dose in clean surgery.- Prolonged antibiotic use based on drain duration is an **outdated practice** that contributes to the emergence of **antibiotic-resistant bacteria**.*Prescribe 3 days of antibiotics as a compromise between no antibiotics and 5 days*- Prescribing antibiotics based on a **compromise** rather than evidence-based guidelines is inappropriate and goes against best **antimicrobial stewardship** practices.- There is no clinical evidence to support a **3-day course** of post-operative prophylactic antibiotics for clean breast surgery with axillary clearance.*Recommend IV antibiotics for 24 hours post-operatively before switching to oral*- Extending prophylactic antibiotics for **24 hours** post-operatively, whether IV or oral, offers no proven additional benefit over a single induction dose for this type of surgery.- This approach unnecessarily increases **healthcare costs**, patient burden, and the potential for **adverse drug reactions** and **catheter-related complications**.
Question 176: A hospital antimicrobial stewardship team reviews prescribing data for urinary tract infections in elderly patients. They identify that 60% of patients aged over 75 years with asymptomatic bacteriuria (positive urine culture without urinary symptoms) are receiving antibiotic treatment. The team implements an intervention targeting this practice. Which of the following would represent the most effective stewardship intervention to address this issue?
A. Implement automatic laboratory reporting of urine cultures with educational comments about treatment indications (Correct Answer)
B. Restrict access to urine culture requests to consultant-level staff only
C. Introduce mandatory infectious diseases consultation before treating any positive urine culture in elderly patients
D. Automatically prescribe nitrofurantoin for all positive urine cultures in elderly patients unless contraindicated
E. Remove urine culture as an available investigation in patients over 75 years without catheter
Explanation: ***Implement automatic laboratory reporting of urine cultures with educational comments about treatment indications***
- This approach is a **point-of-care intervention**, providing immediate, evidence-based guidance to the prescriber at the time of result interpretation.
- It directly addresses the misinterpretation of **asymptomatic bacteriuria** by educating staff that treatment is generally not indicated in the absence of symptoms, thus reducing inappropriate antibiotic use.
*Restrict access to urine culture requests to consultant-level staff only*
- This creates an **unnecessary administrative barrier** that could delay the diagnosis and treatment of genuine, symptomatic urinary tract infections in elderly patients.
- It fails to educate prescribers on the appropriate management of **asymptomatic bacteriuria** and is an inefficient method to curb inappropriate prescribing.
*Introduce mandatory infectious diseases consultation before treating any positive urine culture in elderly patients*
- This intervention is **resource-intensive** and **impractical** for a common finding like bacteriuria, potentially overwhelming ID services and causing significant delays in patient care.
- While valuable for complex cases, making it mandatory for every positive culture is not a scalable or efficient **antimicrobial stewardship strategy** for routine practice.
*Automatically prescribe nitrofurantoin for all positive urine cultures in elderly patients unless contraindicated*
- This directly violates **antimicrobial stewardship principles** by promoting the widespread, often inappropriate, treatment of **asymptomatic bacteriuria**, which drives antibiotic resistance.
- It bypasses essential **clinical judgment**, failing to differentiate between colonization and true infection, and increases the risk of adverse drug events.
*Remove urine culture as an available investigation in patients over 75 years without catheter*
- This extreme measure would prevent the diagnosis of legitimate **symptomatic urinary tract infections** and **urosepsis** in elderly patients, posing significant risks to patient safety.
- Effective stewardship focuses on **optimizing the interpretation and use of diagnostic tests**, not eliminating essential tools, especially when the issue is misapplication of results.
Question 177: A 54-year-old man with morbid obesity (BMI 42 kg/m²) undergoes emergency laparotomy for perforated sigmoid diverticulitis. He receives appropriate intraoperative antibiotic prophylaxis with co-amoxiclav 1.2g IV. The operation lasts 4.5 hours. According to antimicrobial stewardship principles for surgical prophylaxis, which of the following represents best practice for intraoperative antibiotic administration?
A. No further intraoperative doses needed; start therapeutic antibiotics post-operatively
B. Administer a second dose of co-amoxiclav 1.2g IV after 3-4 hours during surgery (Correct Answer)
C. Continue co-amoxiclav infusion throughout surgery and for 24 hours post-operatively
D. Increase initial prophylactic dose to co-amoxiclav 2.4g IV but no repeat dosing
E. Add gentamicin 5mg/kg IV intraoperatively due to prolonged surgical time
Explanation: ***Administer a second dose of co-amoxiclav 1.2g IV after 3-4 hours during surgery***
- Intraoperative **repeat dosing** is recommended when the procedure duration exceeds **two half-lives** of the antibiotic or if there is significant blood loss (>1.5L).
- Since **co-amoxiclav** has a half-life of approximately 1 hour, a 4.5-hour surgery requires a second dose to maintain **minimum inhibitory concentrations (MIC)** in the tissues.
*No further intraoperative doses needed; start therapeutic antibiotics post-operatively*
- While the patient will eventually need **therapeutic antibiotics** for perforated diverticulitis, intraoperative coverage must remain adequate to prevent **surgical site infection (SSI)**.
- Failing to repeat the dose during a long surgery leaves the patient with **sub-therapeutic levels** during the most critical period of contamination.
*Continue co-amoxiclav infusion throughout surgery and for 24 hours post-operatively*
- Antimicrobial stewardship principles emphasize that **prophylaxis** should generally be limited to a single dose or a 24-hour window, but **continuous infusion** is not standard practice for co-amoxiclav.
- Extending the duration unnecessarily increases the risk of side effects like **Clostridioides difficile** infection and promotes **antimicrobial resistance**.
*Increase initial prophylactic dose to co-amoxiclav 2.4g IV but no repeat dosing*
- While **morbid obesity (BMI >40)** may justify a higher initial dose, it does not compensate for the **pharmacokinetic decay** of the drug over 4.5 hours.
- A higher starting dose will still fall below the **therapeutic threshold** if the procedure lasts significantly longer than the drug's half-life.
*Add gentamicin 5mg/kg IV intraoperatively due to prolonged surgical time*
- Adding a different class like **gentamicin** is not a substitute for maintaining the levels of the primary agent used for **prophylaxis**.
- Unnecessary addition of broad-spectrum agents increases the risk of **nephrotoxicity** and does not address the lack of **beta-lactam coverage** caused by the delay.
Question 178: A 28-year-old healthcare worker develops a paronychia following a needlestick injury while removing an IV cannula from a patient 4 days ago. She has increasing pain, erythema, and swelling around the right index fingernail with purulent discharge. There is no lymphangitis or systemic features. The source patient is known to have hepatitis B infection (HBsAg positive) but is HIV and hepatitis C negative. What is the most appropriate management of the paronychia?
A. Incision and drainage with oral flucloxacillin 500mg four times daily
B. Oral co-amoxiclav 625mg three times daily without drainage
C. Incision and drainage alone without antibiotic therapy (Correct Answer)
D. IV vancomycin pending wound culture results
E. Topical mupirocin ointment three times daily for 7 days
Explanation: ***Incision and drainage alone without antibiotic therapy*** (Keep the correct option at the top and the incorrect options in the order they are provided in the input)
- For an acute paronychia with a **purulent collection** or discharge, physical **drainage** is the definitive treatment to remove the source of infection.
- Professional guidelines and **antimicrobial stewardship** suggest that antibiotics are not required for localized infections unless there is spreading **cellulitis**, **lymphangitis**, or systemic symptoms.
*Incision and drainage with oral flucloxacillin 500mg four times daily*
- Inclusion of **flucloxacillin** is unnecessary in this case because the patient lacks **systemic features** or evidence of spreading soft tissue infection.
- While flucloxacillin covers **Staphylococcus aureus**, adding it to a successfully drained localized abscess does not significantly improve healing rates.
*Oral co-amoxiclav 625mg three times daily without drainage*
- Antibiotics alone are often ineffective for **walled-off collections** like an abscess or paronychia, as they cannot penetrate the purulent cavity effectively.
- Management must prioritize **mechanical evacuation** of the pus rather than systemic antimicrobial therapy.
*IV vancomycin pending wound culture results*
- **Intravenous vancomycin** is an overly aggressive intervention for a localized fingertip infection in a systemically well patient.
- This treatment is reserved for candidates with suspected **MRSA** or severe, deep-space infections showing signs of **sepsis**.
*Topical mupirocin ointment three times daily for 7 days*
- **Topical antibiotics** like mupirocin are suitable for very early, superficial infections or impetigo, but cannot reach the deeper tissue in an established **abscess**.
- Once **purulent discharge** and significant swelling are present, topical agents are insufficient compared to definitive **surgical drainage**.
Question 179: A 66-year-old woman with type 2 diabetes and peripheral neuropathy presents with a painless ulcer on the plantar surface of her right foot present for 3 weeks. The ulcer is 3cm diameter, extends to tendon level, and has purulent discharge with surrounding erythema extending 4cm beyond the ulcer margin. There is crepitus on palpation. Temperature is 38.9°C, HR 108/min, BP 128/82 mmHg. X-ray shows soft tissue gas but no obvious bony involvement. What is the most appropriate immediate management?
A. Commence oral co-amoxiclav and arrange outpatient podiatry review within 1 week
B. Obtain wound swab for culture and commence oral antibiotics pending results
C. Arrange urgent surgical review for debridement and commence broad-spectrum IV antibiotics (Correct Answer)
D. Commence IV flucloxacillin and arrange MRI foot within 48 hours
E. Apply negative pressure wound therapy and commence oral metronidazole
Explanation: ***Arrange urgent surgical review for debridement and commence broad-spectrum IV antibiotics***
- The presence of **crepitus** and **soft tissue gas** on X-ray in a diabetic patient, along with systemic signs of infection (fever, tachycardia), are highly indicative of a **necrotizing soft tissue infection (NSTI)**, a surgical emergency.
- Immediate and aggressive management involves **urgent surgical debridement** to remove necrotic tissue and **broad-spectrum intravenous antibiotics** to cover the polymicrobial flora, including anaerobes, typically seen in such severe infections.
*Commence oral co-amoxiclav and arrange outpatient podiatry review within 1 week*
- **Oral antibiotics** are inadequate for a severe, deep-seated infection with systemic symptoms and evidence of tissue gas, which demands immediate, high-dose intravenous therapy.
- Arranging an **outpatient review** within a week is dangerously delayed for a rapidly progressing infection that requires emergency hospitalization and intervention to prevent sepsis, limb loss, or mortality.
*Obtain wound swab for culture and commence oral antibiotics pending results*
- **Wound swabs** are often contaminated with superficial flora and may not accurately reflect the deep tissue pathogens; deep tissue cultures obtained during surgery are more reliable.
- Delaying definitive treatment for culture results while only initiating **oral antibiotics** is inappropriate and unsafe given the clinical signs of a severe, potentially necrotizing infection.
*Commence IV flucloxacillin and arrange MRI foot within 48 hours*
- **Flucloxacillin** provides narrow-spectrum coverage primarily against Gram-positive bacteria, lacking essential coverage for common Gram-negative and anaerobic pathogens in diabetic foot infections with gas.
- While MRI is excellent for evaluating **osteomyelitis**, its use should not delay the critical **surgical debridement** required for a necrotizing infection, which is the immediate priority.
*Apply negative pressure wound therapy and commence oral metronidazole*
- **Negative pressure wound therapy (NPWT)** is typically reserved for wound bed preparation and closure *after* the acute infection has been surgically controlled and necrotic tissue removed, not as an initial treatment for active infection with crepitus.
- **Oral metronidazole** alone is insufficient; it only covers anaerobes and fails to address the broad spectrum of aerobic Gram-positive and Gram-negative bacteria often involved in deep diabetic foot infections.
Question 180: A 33-year-old man who recently started attending a gym presents with multiple painful, erythematous pustules and small abscesses on his buttocks and thighs. He reports several gym members have had similar lesions. On examination, there are multiple follicular-based pustules with surrounding erythema, some with small fluctuant areas. Temperature is 37.5°C. What is the most likely causative organism and most appropriate initial management?
A. Candida albicans; prescribe topical clotrimazole cream
B. Staphylococcus aureus; prescribe oral flucloxacillin and advise on hygiene measures (Correct Answer)
C. Pseudomonas aeruginosa; prescribe oral ciprofloxacin
D. Streptococcus pyogenes; prescribe oral phenoxymethylpenicillin
E. Herpes simplex virus; prescribe oral aciclovir
Explanation: ***Staphylococcus aureus; prescribe oral flucloxacillin and advise on hygiene measures***
- The clinical presentation of **follicular-based pustules** and abscesses (furunculosis) in a gym setting is highly characteristic of **Staphylococcus aureus** infection, commonly spread via shared equipment.
- **Oral flucloxacillin** is the gold-standard treatment for staphylococcal skin infections, and **hygiene measures** are essential to prevent outbreaks and recurrence.
*Candida albicans; prescribe topical clotrimazole cream*
- **Candida** typically presents as **satellite lesions** in intertriginous (skin-fold) areas, rather than primary follicular pustules on the thighs.
- This patient's presentation and epidemiological link to gym members favor a **bacterial** over a fungal etiology.
*Pseudomonas aeruginosa; prescribe oral ciprofloxacin*
- Known as **"hot tub folliculitis,"** this usually presents as an itchy rash after exposure to contaminated water rather than deep, painful abscesses.
- **Pseudomonas** folliculitis is often self-limiting and does not typically require **ciprofloxacin** unless the patient is immunocompromised or has systemic symptoms.
*Streptococcus pyogenes; prescribe oral phenoxymethylpenicillin*
- While a common skin pathogen, **Streptococcus pyogenes** more frequently causes spreading **cellulitis** or **erysipelatous** plaques rather than discrete follicular-based pustules.
- **Phenoxymethylpenicillin** lacks sufficient coverage for **Staphylococcus aureus**, which is the more likely culprit for furunculosis.
*Herpes simplex virus; prescribe oral aciclovir*
- **HSV** infections typically present as **grouped vesicles** on an erythematous base rather than widespread pustules and fluctuant abscesses.
- Viral folliculitis is less common than bacterial in a gym outbreak and would not respond to the high-temperature **fluctuance** described here.
