11/10/2016. Skin and Soft Tissue Infections. Disclosures. Educational Need/Practice Gap. Objectives. Case #1

Transcription

1 Disclosures Selecting Antimicrobials for Common Infections in Children FMR-Contemporary Pediatrics 11/2016 Sean McTigue, MD Assistant Professor of Pediatrics, Pediatric Infectious Diseases Medical Director for Pediatric Infection Prevention and Control I have no financial interests or other potential conflicts to disclose. I may discuss off-label use of medications but this will be limited to non-experimental clinical use of antimicrobials for indications and/or patient populations other than those approved by the FDA. Educational Need/Practice Gap Objectives Gap In children with common infections, there is sometimes a difference between what is prescribed and what would be more optimal. Need In a landscape of emerging antimicrobial resistance, the primary care provider needs more up-to-date understanding of the epidemiology of pediatric infections and the options available to him/her for management. At the conclusion of this activity The learner will be able to identify the most likely pathogens present in common pediatric infections. The learner will be able to describe the current expected susceptibility of common pathogens encountered in pediatric infections. The learner will be able to chose an appropriate antimicrobial for a child with a common pediatric infection based on current epidemiology and susceptibility data. Case #1 A 2yo boy is brought to your office by his parents with a knot in his diaper area. He is afebrile and systemically well but has a small superficial abscess with some associated cellulitis. Skin and Soft Tissue Infections 1

2 Superficial skin infections including abscess and cellulitis are exceedingly common and have increased in incidence with the emergence of community associated MRSA (CaMRSA) Staphylococcus aureus and Streptococcus pyogenes remain the most common causes of superficial skin infection with CaMRSA representing a large percentage of cases. Abscesses are primarily caused by Staphylococcus aureus with a much smaller burden of disease caused by GAS For superficial skin infections where Staphylococcus aureus is most likely, the optimal antimicrobial choice is between oral clindamycin and oral trimethoprim-sulfamethoxazole Tmp-Smx slightly better susceptibility (98% vs. 91%) with better palatability and easier dosing (BID vs TID) Clindamycin fewer drug reactions and also covers Streptococcus pyogenes For SSTI such as cellulitis where Streptococcus pyogenes becomes more of a consideration in addition to Staphylococcus aureus, clindamycin is a better option than Tmp-Smx. If clindamycin not tolerated (unpalatable) an option is to use Tmp-Smx and to consider adding a beta-lactam such as amoxicillin or penicillin for strep For skin infections classically caused by Streptococcus pyogenes, it is reasonable to consider using a beta-lactam alone. SSTI typically caused by Streptococcus pyogenes Bite wounds Lymphangitis Erysipelas Blistering distal dactylitis The microbiology of bite wounds (human and animal) is quite different from other SSTI. Human bites typically involve polymicrobial infection with oral flora such as: Eikenella corrodens Streptococci (including Streptococcus pyogenes) Oral anaerobes Dog and Cat bites also polymicrobial Pasteurella multocida (and P. canis) Recommended therapy (and prophylaxis) for bite wounds (human or animal) is amoxicillin-clavulanate. If PCN allergic, TMP-SMX + clindamycin 2

3 Case #2 A 4yo girl is brought to your office by her parents with fever and dysuria. Urine dipstick analysis reveals large leukocyte esterase and positive nitrite. Urinary Tract Infections are more common in children <1 year of age but can be seen at any age. Most are caused by enteric flora E. coli is the most common urinary pathogen Less common organisms include Klebsiella, Proteus, Enterococcus, Pseudomonas, and Enterobacter Staphylococcus saprophyticus causes >15% of in adolescent females Urinary tract pathogens including E. coli are becoming increasingly resistant to amoxicillin, amoxicillin-clavulanate, and Tmp-Smx. Oral cephalosporins and nitrofurantoin are significantly more reliable against E. coli Nitrofurantoin is very reliably active and shares no cross-resistance with other antimicrobial classes Nitrofurantoin should NOT be used for suspected upper tract infection due to subtherapeutic serum and renal concentrations Active only in the urine Cefdinir or Cefixime are the most reliably active oral agents that also reach therapeutic levels in the blood and renal parenchyma When culture results are available Appropriate to step down to a narrower spectrum agent based on susceptibility data, especially if there is any intolerance or side effect from the initial regimen, but most would continue the initial drug if active. What about ESBL producing organisms? Nitrofurantoin if lower tract disease and susceptible 3

4 Streptococcal Pharyngitis Streptococcal pharyngitis There is no role for medications other than IM benzathine penicillin, penicillin V, or amoxicillin in the treatment of streptococcal pharyngitis except for those with penicillin allergies. Amoxicillin 50 mg/kg (max 1 gram) once daily x 10 days For the penicillin allergic patient: If no history of anaphylaxis, a narrow spectrum cephalosporin such as cephalexin x 10 days is recommended For patients with anaphylactic reactions, clindamycin 30 mg/kg/day divided TID (to a max of 900 mg/day) x 10 days Macrolides are an acceptable alternative but have been associated with treatment failures (up to 20% resistance in some studies) Respiratory Tract Infections Respiratory Tract Infections Respiratory Tract Infections Acute otitis media and acute sinusitis share identical microbiology. Streptococcus pneumoniae Non-typeable Haemophilus influenzae Moraxella catarrhalis Penicillin non-susceptible pneumococcus is becoming increasingly common and has led to AAP recommendations for high dose amoxicillin (90 mg/kg/day) or IM ceftriaxone for treatment of AOM. Oral cephalosporins reach levels in the middle ear sufficient only to treat penicillin susceptible strains of pneumococcus Increasing resistance to macrolides 4

5 Respiratory Tract Infections Note that when using ceftriaxone for otitis media, there are 2 different regimens For initial therapy of uncomplicated AOM, a single IM dose of ceftriaxone 50 mg/kg can be given as definitive therapy For children with treatment failure or relapse ceftriaxone should be given as a 3 day regimen of 50 mg/kg each day Pneumonia Sinusitis Recommendations (found in the text) are nearly identical as those for otitis media and sinusitis with amoxicillin or amoxicillin-clavulanate. For penicillin allergy: cephalosporin +/- clindamycin (no anaphylaxis) or potentially levofloxacin for those with anaphylaxis. HSV A quick note on Herpes (the gift that keeps on giving) Acyclovir is poorly absorbed across the GI tract, therefore oral doses must be higher than those given IV for similar effect My recommended dose for PO treatment of orolabial HSV infection or HSV stomatitis Acyclovir 80 mg/kg/day divided Q6 hours x 5-10 days (5-7 days is usually more than enough) For those >/= 12yo: Valacyclovir 2 grams PO Q12 hours x 1 day Suppressive therapy for recurrent mucocutaneous HSV Acyclovir 30 mg/kg/day divided Q8 hours For those >/= 12yo: Valacyclovir mg once daily 5

6 Questions? 6