A few ID pearls

A 37-year-old man presents for the evaluation of localized swelling and tenderness of the left leg just below the knee. He suspects this lesion developed after a spider bite, although he did not see a spider. Examination of the leg reveals an area of erythema and warmth measuring approximately 5 by 7 cm. At the center of the lesion is a fluctuant area measuring approximately 2 by 2 cm, overlaid by a small area of necrotic skin. The man's temperature is 38.3°C. The pulse rate is 115 beats per minute. The blood pressure is 116/78 mm Hg. How should this patient be evaluated and treated? A 37-year-old man presents for the evaluation of localized swelling and tenderness of the left leg just below the knee. He suspects this lesion developed after a spider bite, although he did not see a spider. Examination of the leg reveals an area of erythema and warmth measuring approximately 5 by 7 cm. At the center of the lesion is a fluctuant area measuring approximately 2 by 2 cm, overlaid by a small area of necrotic skin. The man's temperature is 38.3°C. The pulse rate is 115 beats per minute. The blood pressure is 116/78 mm Hg. How should this patient be evaluated and treated?

Risk Factors for MRSA Recent ABX use. Recent ABX use. Recent hospitalization Recent hospitalization HD HD IVDU IVDU DM DM Previous MRSA infection/colonization Previous MRSA infection/colonization

Initial treatment Best initial treatment Best initial treatment I&D of “small” abscesses I&D of “small” abscesses Small = less than 5cm in length Small = less than 5cm in length Randomized trial of 166 patients with uncomplicated skin abscesses at risk for community-associated MRSA (CA-MRSA) who were managed with cephalexin or placebo following incision and drainage of skin and soft tissue abscesses. Randomized trial of 166 patients with uncomplicated skin abscesses at risk for community-associated MRSA (CA-MRSA) who were managed with cephalexin or placebo following incision and drainage of skin and soft tissue abscesses. The cure rates were similar in the two groups (84 and 90 percent, respectively). The cure rates were similar in the two groups (84 and 90 percent, respectively).

MRSA Skin and Soft Tissue Infections Patients with larger areas of infection and/or systemic signs of infection should be managed with antimicrobial therapy. Patients with larger areas of infection and/or systemic signs of infection should be managed with antimicrobial therapy. Empiric therapy Empiric therapy Beta-lactam antibiotics are no longer reliable empiric therapy for skin and soft tissue infections. Beta-lactam antibiotics are no longer reliable empiric therapy for skin and soft tissue infections. Local incidence rate = 56% Local incidence rate = 56%

Options for therapy Clindamycin Clindamycin Use caution if local resistance rate is 10-15% Use caution if local resistance rate is 10-15% TMP/SMX TMP/SMX Use based on observational study only Use based on observational study only Tetracyclines (Doxy or Mino) Tetracyclines (Doxy or Mino) Also from observational/retrospective data Also from observational/retrospective data Linezolid Linezolid Rifampin Rifampin

MRSA Skin and Soft Tissue Infections Bottom line Bottom line I&D is essential for abscesses I&D is essential for abscesses Pay attention to local resistance patterns Pay attention to local resistance patterns Beta-lactams are no longer viable first choices for empiric treatment of at-risk patients Beta-lactams are no longer viable first choices for empiric treatment of at-risk patients TMP/SMX is good parenteral option but evidence is observational. TMP/SMX is good parenteral option but evidence is observational. Linezolid second choice for those that cannot tolerate first choice meds. Linezolid second choice for those that cannot tolerate first choice meds.

A 37 year old man comes to the clinic with a 7-day history of coarse productive cough, fatigue/malaise, sore throat, nasal congestion and runny nose, and mild shortness of breath. His medical history is unremarkable. His vital signs include a temp of 99.1, RR of 18 and BP of 125/78. Examination reveals slightly erythematous oropharynx and very faint wheezes on chest exam but is otherwise unremarkable. What is the most likely diagnosis and treatment? A 37 year old man comes to the clinic with a 7-day history of coarse productive cough, fatigue/malaise, sore throat, nasal congestion and runny nose, and mild shortness of breath. His medical history is unremarkable. His vital signs include a temp of 99.1, RR of 18 and BP of 125/78. Examination reveals slightly erythematous oropharynx and very faint wheezes on chest exam but is otherwise unremarkable. What is the most likely diagnosis and treatment?

A 37 year old man comes to the clinic with a 7- day history of coarse productive cough, fatigue/malaise, sore throat, nasal congestion and runny nose, and mild shortness of breath. His medical history includes poorly controlled diabetes, HTN, CAD and childhood asthma. His vital signs include a temp of 99.1, RR of 18 and BP of 125/78. Examination reveals slightly erythematous oropharynx and very faint wheezes on chest exam. There are multiple small pustular skin lesions over his trunk and legs which he says were diagnosed as “staph” by a previous physician. What is the most likely diagnosis and treatment? A 37 year old man comes to the clinic with a 7- day history of coarse productive cough, fatigue/malaise, sore throat, nasal congestion and runny nose, and mild shortness of breath. His medical history includes poorly controlled diabetes, HTN, CAD and childhood asthma. His vital signs include a temp of 99.1, RR of 18 and BP of 125/78. Examination reveals slightly erythematous oropharynx and very faint wheezes on chest exam. There are multiple small pustular skin lesions over his trunk and legs which he says were diagnosed as “staph” by a previous physician. What is the most likely diagnosis and treatment?

A 37 year old man comes to the clinic with a 7- day history of coarse productive cough, fatigue/malaise, sore throat, nasal congestion and runny nose, and mild shortness of breath. His medical history includes HIV/AIDS, chronic diarrhea, and medical noncompliance. His vital signs include a temp of 99.1, RR of 18 and BP of 125/78. Examination reveals slightly erythematous oropharynx and very faint wheezes on chest exam but is otherwise unremarkable. What is the most likely diagnosis and treatment? A 37 year old man comes to the clinic with a 7- day history of coarse productive cough, fatigue/malaise, sore throat, nasal congestion and runny nose, and mild shortness of breath. His medical history includes HIV/AIDS, chronic diarrhea, and medical noncompliance. His vital signs include a temp of 99.1, RR of 18 and BP of 125/78. Examination reveals slightly erythematous oropharynx and very faint wheezes on chest exam but is otherwise unremarkable. What is the most likely diagnosis and treatment?

Epidemiology Usual causes of AB: Usual causes of AB: Influenza A/B Influenza A/B Parainfluenza Parainfluenza Coronavirus Coronavirus Rhinovirus Rhinovirus RSV RSV

Stats How many patients diagnosed with acute bronchitis are given antibiotics? How many patients diagnosed with acute bronchitis are given antibiotics? 60-70% 60-70%

S pneumo, H flu, S aureus, M cat “There is no convincing evidence to support the concept of "acute bacterial bronchitis" caused by these pathogens in adults, with the exception of patients with airway violations such as tracheostomy or endotracheal intubation, or those with exacerbations of chronic bronchitis.” “There is no convincing evidence to support the concept of "acute bacterial bronchitis" caused by these pathogens in adults, with the exception of patients with airway violations such as tracheostomy or endotracheal intubation, or those with exacerbations of chronic bronchitis.”

Acute Bronchitis “Routine antibiotic treatment of uncomplicated acute bronchitis is not recommended. If pertussis infection is suspected (an unusual circumstance), a diagnostic test should be performed and antimicrobial therapy initiated.” “Routine antibiotic treatment of uncomplicated acute bronchitis is not recommended. If pertussis infection is suspected (an unusual circumstance), a diagnostic test should be performed and antimicrobial therapy initiated.”

Acute Bronchitis Diagnosis Productive cough as the essential symptom Productive cough as the essential symptom Concurrent URI symptoms Concurrent URI symptoms Rhinitis, sore throat, hoarseness Rhinitis, sore throat, hoarseness Fever is unusual sign and may suggest pneumonia or influenza Fever is unusual sign and may suggest pneumonia or influenza

AB vs pneumonia When to order a CXR? When to order a CXR? Abnormal VS (HR>100, RR>24, Temp>38C) Abnormal VS (HR>100, RR>24, Temp>38C) Rales or signs of consolidation on exam Rales or signs of consolidation on exam Advanced age (>75 years) Advanced age (>75 years)

Duration of cough What if cough is present for 2 weeks? What if cough is present for 2 weeks? Selected studies have recovered pertussis in up to 10% to 20% of patients with cough lasting longer than 2 to 3 weeks. Selected studies have recovered pertussis in up to 10% to 20% of patients with cough lasting longer than 2 to 3 weeks. Clinicians should limit suspicion and treatment of adult pertussis to adults with a high probability of exposure to pertussis—for example, during documented outbreaks. Clinicians should limit suspicion and treatment of adult pertussis to adults with a high probability of exposure to pertussis—for example, during documented outbreaks. Pertussis may be suspected regardless of immunization history. Pertussis may be suspected regardless of immunization history.

Treatment of AB NSAIDs, Tylenol, nasal decongestants NSAIDs, Tylenol, nasal decongestants Strong patient-physician relationship and good communication Strong patient-physician relationship and good communication Reassurance Reassurance

Evidence against ABX for AB A meta-analysis of 9 studies: A meta-analysis of 9 studies: 5 of 9 showed no benefit of either doxycycline or erythromycin 5 of 9 showed no benefit of either doxycycline or erythromycin 2 showed slight clinical differences in patients treated with erythromycin or TMP/SMX 2 showed slight clinical differences in patients treated with erythromycin or TMP/SMX 2 showed superiority of albuterol to erythromycin 2 showed superiority of albuterol to erythromycin A second meta-analysis showed a 0.6 day reduction in cough duration. A second meta-analysis showed a 0.6 day reduction in cough duration. Another study showed Azithromycin and Vitamin C were equivalent. Another study showed Azithromycin and Vitamin C were equivalent.

Patient information Because the prevailing thought among many patients is that “antibiotics will treat my cough”, patient information/hand-outs are available to provide further reassurance that they are being treated appropriately and in line with current recommendations. Because the prevailing thought among many patients is that “antibiotics will treat my cough”, patient information/hand-outs are available to provide further reassurance that they are being treated appropriately and in line with current recommendations.

A 57 year old man with cirrhosis is ready to go home after an ICU admission and treatment of acute variceal hemorrhage. He has never had a GIB before. Besides the usual medications aimed at preventing recurrent GI bleeding, should he take any other preventative medications? A 57 year old man with cirrhosis is ready to go home after an ICU admission and treatment of acute variceal hemorrhage. He has never had a GIB before. Besides the usual medications aimed at preventing recurrent GI bleeding, should he take any other preventative medications?

Prophylaxis for SBP Risk factors have been identified Risk factors have been identified AF protein concentration < 1 AF protein concentration < 1 Variceal hemorrhage Variceal hemorrhage Prior episode of SBP Prior episode of SBP Most flora originate in the gut Most flora originate in the gut Theory: Intestinal decontamination can reduce SBP incidence in at risk patients. Theory: Intestinal decontamination can reduce SBP incidence in at risk patients.

Does prophylaxis work? Meta-analysis of 13 RCTs (hospitalized patients with cirrhosis with risk factors for infection) Meta-analysis of 13 RCTs (hospitalized patients with cirrhosis with risk factors for infection) Significant mortality benefit Significant mortality benefit RR 0.70, CI RR 0.70, CI Significant reduction in SBP development Significant reduction in SBP development RR 0.39, CI RR 0.39, CI Antibiotic prophylaxis in cirrhotic patients with gastrointestinal bleeding was studied via systematic review. Antibiotic prophylaxis in cirrhotic patients with gastrointestinal bleeding was studied via systematic review. Significantly reduced SBP development, bacteremia and death. Significantly reduced SBP development, bacteremia and death.

Regimens Single weekly Cipro vs placebo Single weekly Cipro vs placebo 3.6 versus 22 percent 3.6 versus 22 percent Bactrim DS 1 tab daily 5 days/week Bactrim DS 1 tab daily 5 days/week 3 versus 27 percent 3 versus 27 percent Continuous oral Cipro (reduced mortality and incidence of SBP at 12 months) Continuous oral Cipro (reduced mortality and incidence of SBP at 12 months) Continous TMP/SMX 1 tab daily Continous TMP/SMX 1 tab daily Inpatient-only use of norfloxacin with discontinuation at time of discharge. Inpatient-only use of norfloxacin with discontinuation at time of discharge.

Recommendations Those with gastrointestinal bleeding Those with gastrointestinal bleeding Cefotaxime IV until taking PO then switch to Norfloxacin PO x 7 days total. Cefotaxime IV until taking PO then switch to Norfloxacin PO x 7 days total. Continuous quinolone or TMP/SMX in those who have had one or more episodes of SBP Continuous quinolone or TMP/SMX in those who have had one or more episodes of SBP Switch antibiotics if develops SBP on this regimen Switch antibiotics if develops SBP on this regimen Short-term norfloxacin or TMP/SMX (in-patient only) in those with cirrhosis and AF protein <1g/dl hospitalized for another reason. Short-term norfloxacin or TMP/SMX (in-patient only) in those with cirrhosis and AF protein <1g/dl hospitalized for another reason.