Disclosures Consultant: Genentech Skin and soft tissue infections - - PDF document

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Skin and soft tissue infections

Sarah Doernberg, MD, MAS Associate Professor Medical Director of Antimicrobial Stewardship

Disclosures

§ Consultant: Genentech

Outline

§ Cellulitis § Necrotizing infections § Special populations and exposures § Abscess

Case #1: 63 y/o M with DMII, chronic venous stasis, and CHF presents to your clinic with 1 day of LLE erythema and warmth. He lives at home, has no recent hospitalizations, and denies prior history of skin infections. NKDA. Exam: Afebrile, well-appearing, cellulitis of LLE to knee without purulence. What antibiotic would you like to prescribe?

A.

Cephalexin + tmp/smx PO

B.

Clindamycin PO

C.

Linezolid PO

D.

Cephalexin PO

E.

Vancomycin IV

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Is MRSA coverage for non-purulent cellulitis needed #1?

Pallin DJ et al. Clin Infect Dis. 2013 Jun;56(12):1754-62. doi: 10.1093/cid/cit122. Epub 2013 Mar 1.

• >12 y/o
• Cellulitis d/c home
• No abscess
• 3 EDs

(mITT, N = 146)

LEX + PBO (N = 73) LEX + SXT (N = 73)

< 24h CFZ

• r NAF

(~25%)

§ Rx 7-14 dd

1○ endpoint:

• Rx success

2○ endpoints:

• Abscess
• Adverse events

What happened?

30-day cure Failure:

• Hospitalization
• Δ in Abx
• Drainage of abscess
• Recurrence

82% LEX vs. 85% +SXT 2.7% (-9.3 to 15%) Abscess 6.8% LEX vs. 6.8% +SXT 0% (-8.2 to 8.2%) Adverse event

GI effects most common

Pallin DJ et al. Clin Infect Dis. 2013 Jun;56(12):1754-62. doi: 10.1093/cid/cit122. Epub 2013 Mar 1.

53% LEX vs. 49% +SXT −4.1 (−20% to 12%)

Is MRSA coverage for non-purulent cellulitis needed #2?

• >12 y/o
• Cellulitis
• Median 10x13 cm
• Included DM (11%)
• No abscess/pus/wound
• 5 EDs

LEX + PBO (N = 248) LEX + SXT (N = 248)

ultrasound to exclude abscess

§ Rx 7 dd

Cure (superiority) (per protocol)

Absence of:

• D3-4: fever, >25% ↑

erythema, swelling, tenderness

• D8-10: No ↓ erythema,

swelling, tenderness

• D14-21: More than

minimal erythema, swelling, tenderness

Moran GJ et al. JAMA. 2017 May 23;317(20):2088-2096. doi: 10.1001/jama.2017.5653.

What happened?

Cure Per protocol: 86% LEX vs. 84% +SXT

• 2.0% (-9.7 to 5.7%)

mITT-1 69% LEX vs. 76% +SXT 7.3% (-1.0 to 15.5%) Hospitalization 5.2% LEX vs. 7.8% +SXT 2.6% (-2.6 to 7.8) Adverse event

GI effects most common

73.4% LEX vs. 75% +SXT

Moran GJ et al. JAMA. 2017 May 23;317(20):2088-2096. doi: 10.1001/jama.2017.5653.

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Who was left out?

§ DM § Peripheral vascular disease § Renal insufficiency § Requires admission § Purulent discharge § Cellulitis associated with

hardware or device

§ Immunocompromised § Face, perianal, periungual § Bite § Immersion § IVDU § Multifocal infection § Underlying skin disease § Pregnant/lactating

Pallin DJ et al. Clin Infect Dis. 2013 Jun;56(12):1754-62. doi: 10.1093/cid/cit122. Epub 2013 Mar 1. Moran GJ et al. JAMA. 2017 May 23;317(20):2088-2096. doi: 10.1001/jama.2017.5653.

How long should you treat?

Randomized, double blind RCT

5 days (n = 43) 10 days (n = 44)

Could get 24h of another drug Inpatient or outpatient Sickest excluded

Resolution @ 14 days without relapse @ 28 days

98% 98%

Most subjects still had mild residual signs of cellulitis at day 5 that resolved without further antibiotics

Hepburn MJ et al. Arch Intern Med. 2004 Aug 9-23;164(15):1669-74.

Bottom line

§ Cephalexin is first-line for uncomplicated outpt cellulitis § 5 days unless slow resolution or complicated course § In those patients, even if failure, invasive infection rare

• Often failure due to unrecognized abscess

§ May need to consider MRSA or other coverage if:

• Immunocompromised
• IVDU
• Associated with ulceration or hardware
• Animal exposure
• Immersion

Case, con’t: Your patient returns to clinic two days later for a scheduled wound check. He reports excellent adherence with the antibiotics, but states that his leg is not improved. On exam, temp is 38, other vitals stable; well-appearing, erythema now extends 2 inches above the knee. No purulence noted. What is your next step?

• A. Switch to linezolid and schedule a follow-up in 2 days
• B. Switch to linezolid, obtain an ultrasound, and schedule a

follow-up in 2 days

• C. Admit, obtain an ultrasound, switch to vancomycin
• D. Admit, obtain an ultrasound, switch to vancomycin and

piperacillin/tazobactam

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IDSA recommendations

Patients who have failed oral antibiotic treatment Treat as a severe infection (i.e. vancomycin + piptazo)

§ Is this really needed?

Stevens DL et al. CID 2014; 59(2), e10–e52

Reasons for failing outpatient therapy

§ Medication nonadherence or malabsorption § Wrong diagnosis § Resistant bacteria § Nonbacterial infection § Abscess/deep infection § Anatomic issues (e.g. lymphedema, venous stasis) slowing

response

§ Organism is eradicated but inflammation persists

DDx to revisit in a stable patient

§

Drug reaction

§

Contact dermatitis

§

Venous stasis dermatitis

§

DVT

§

Superficial thrombophlebitis

§

Hematoma

§

Gout

§

Vasculitis

§

Erythema nodosum

§

Sarcoidosis

§

Eosinophilic cellulitis

§

Panniculitis

§

Neoplasia (Paget’s dz

• f the breast, CTCL)

§

Insect bite reaction

§

Injection site reaction

§

Pyoderma gangrenosum

§

IV line infiltration

§

Erythema migrans

§

HSV, VZV

§

Fungal infection

§

Abscess, septic arthritis/bursitis,

• steomyelitis, mycotic

aneurysm

Raff AB and Korshinsky D. JAMA. 2016;316(3):325-337. doi:10.1001/jama.2016.8825

Cellulitis can be challenging to diagnose

§ Retrospective study of 74 Dermatology consults for cellulitis at

4 academic medical centers

• 55 (74%) diagnosed with pseudocellulitis
• Common final diagnoses:

§ stasis dermatitis (31%) § contact dermatitis (15%) § inflammatory tinea (9%)

Strazzula L et al. J Am Acad Derm 2015; 73(1): 70-75

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Dermatology consults for cellulitis in the office setting

• Cellulitis dx’d by PCP
• Stable
• No immunocompromise

Derm consult (N = 20) Blinded derm eval (N = 9) 2 (10%) dx’d with cellulitis

• 2 (10%)àabx
• All better @ 1 wk

f/u 3 (33%) dx’d with cellulitis

• 9 (100%)àabx

Arakaki RY et al. JAMA Dermatol. 2014;150(10):1056-1061. doi:10.1001/jamadermatol.2014.1085

ID consults can help, too

§ Outpatients with cellulitis deemed to need IV abx

• Pre period: ED-staffed clinic
• Post period: ID-staffed clinic

Jain SR et al. Diag Micro and ID 2017; 87(4): 371-375

ED (149) ID (136) P value Cellulitis confirmed 133 (89%) 82 (60%) < 0.0001 Antibiotics stopped 0 16 (11%) <0.0001 Admission 11 (7%) 2 (1.5%) 0.01

Oral antibiotic failure risk factors

N = 497 pts discharged from ED with cellulitis Failure = hospitalization or Δ of antibiotics for worsening ifxn

102 (21%) failed

• 78% for Δ abx
• 22% for hospitalization

Risk factors for failure (OR, 95% CI)

• Fever @ initial triage: 4.3 (1.6-11.7)
• Leg ulcers: 2.5 (1.1-5.2)
• Lymphedema: OR 2.5 (1.5-4.2)
• Prior cellulitis: OR 2.1 (1.3-3.5)

Quirke M et al. BMJ Open. 2015 Jun 25;5(6):e008150. doi: 10.1136/bmjopen-2015-008150.

Microbiology of oral antibiotic failure

§ Multicenter retrospective cohort of inpatients with SSTIs (N = 533)

• 179/533 (34%) got prior abx

§ Those failing outpatient abx had fewer comorbidities, less fever, and

lower WBCs and CRP

§ 100% of those failing outpatient PO rx survived to discharge

Jenkins TC et al. Am J Emerg Med. 2016 Jun;34(6):957-62. doi: 10.1016/j.ajem.2016.02.013. Epub 2016 Feb 12.

Organism No PO abx (354) PO abx (179) P value Any 139 (39) 63 (35) 0.4 MRSA 38 (27) 26 (41) 0.05 GNR 18 (13) 2 (3) 0.03

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Key interventions if outpatient rx fails

§ Revisit the diagnosis § Ensure adequate drainage § Address underlying anatomical issues

• Edema, tinea

§ Coverage of MRSA

• GNR coverage probably not needed unless unstable

When is MRSA coverage indicated for cellulitis?

§ Hemodynamic instability § Overlying/associated with an indwelling medical device § Known MRSA colonization § Recent prior MRSA infection § Heavy hospital exposure (including dialysis, longterm care) § Injection drug use § Lack of response to a regimen not covering MRSA

Case, con’t: You switch your patient to IV vancomycin, and he responds well to therapy with regression of the erythema and resolution of the fever. On day #3, he is ready to go home. What

• ral antibiotic will you give him and for what duration?
• A. Cephalexin; 5 days from admission
• B. Cephalexin; 10 days from admission
• C. TMP/SMX plus amoxicillin; 5 days from admission
• D. TMP/SMX plus amoxicillin; 10 days from admission
• E. Oritavancin x 1 dose
• F. Place a PICC and administer vancomycin x 10 days

What about these new long-acting abx?

§ Dalbavancin and oritavancin = long-acting lipoglycopeptides

Boucher HW et al. N Engl J Med. 2014 Jun 5;370(23):2169-79. doi: 10.1056/NEJMoa1310480. Corey GR et al. N Engl J Med. 2014 Jun 5;370(23):2180-90. doi: 10.1056/NEJMoa1310422. Corey GR et al. Clin Infect Dis. 2015 Jan 15;60(2):254-62. doi: 10.1093/cid/ciu778.

Study Drug Comparator Outcome DISCOVER I and II Dalbavancin day 1 and 8 VANàLZD x 10-14 days Noninferior SOLO I and II Oritavancin x 1 VAN x 7-10 days Noninferior Dalba dosing trial Dalbavancin 1500 mg x 1 Dalba 1000 mg day 1 and 500 mg day 8 Noninferior

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Case, con’t: Your patient recovers from his infection and does well. He is diligent about wearing compression stockings and has treated his tinea pedis. However, over the next several months, he presents with another episode of cellulitis of the same leg on 3 different occasions. He has complete resolution

• f symptoms between episodes. He wants to know if there’s anything he

can do to prevent this in the future. What do you recommend?

• A. Swab nares for MRSA and treat with chlorhexidine if positive
• B. Obtain an MRI to look for bone infection
• C. Obtain a skin biopsy
• D. Start penicillin VK 250 mg po twice daily
• E. Start erythromycin 250 mg po twice daily

Pathophysiology of recurrent cellulitis

Risk factors:

• Tinea
• Lymphedema
• Venous stasis
• Obesity

Cellulitis Impaired drainage, worsening anatomic issues

Dalal A et al. Cochrane Database Syst Rev. 2017 Jun 20;6:CD009758. doi: 10.1002/14651858.CD009758.pub2.

Prophylaxis for recurrent cellulitis

• ↑adverse events with erythromycin
• No difference in hospitalizations
• Effect disappeared after prophylaxis stopped

Erythromycin Penicillin

Options for prophylaxis

§

Penicillin V 250 mg po twice daily (preferred)

§

Benzathine PCN G 1.2 million units q2-4 weeks (600,000 units if < 27 kg)

§

PCN allergy: erythromycin 250 mg po twice daily

• ↑ risk of AEs

§

Alternative: Early patient-initiated therapy, not well studied

§

Do not forget non-antibiotic interventions!

• Treat tinea
• Address edema
• Weight loss

Thomas KS et al. N Engl J Med. 2013 May 2;368(18):1695-703. doi: 10.1056/NEJMoa1206300; Kremer M, et al. J Infect. 1991 Jan;22(1):37-40; Dalal A et al. Cochrane Database Syst Rev. 2017 Jun 20;6:CD009758. doi: 10.1002/14651858.CD009758.pub2.

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Outline

ü Cellulitis § Necrotizing infections § Special populations and exposures § Abscess

Case, con’t. You start your patient on penicillin VK, and he does

• well. The next time you see him, though, is in the ICU where he is

visiting his wife. She has presented to the hospital with erythema

• f her elbow after falling while playing tennis, resulting in an
• abrasion. On PE: T39C, HR 120s, BP 100/50. She appears

uncomfortable and is disoriented. Her elbow is erythematous, swollen, and exquisitely tender to palpation. What is the most important next step?

• A. Start vancomycin, piperacillin/tazobactam, and clindamycin
• B. Start vancomycin and meropenem
• C. Obtain a stat CT scan
• D. Obtain a surgical consultation

Wong CH and Wang YS. Curr Opin Infect Dis. 2005 Apr;18(2):101-6. https://commons.wikimedia.org/wiki/File:Beginning_of_Necrotizing_Fasciitis_01.jpg https://upload.wikimedia.org/wikipedia/commons/b/b3/Very_early_symptom_of_NF.jpg https://upload.wikimedia.org/wikipedia/commons/6/6a/Necrotizing_fasciitis_left_leg.JPEG

Necrotizing soft tissue infection features

Stage I

• Tenderness
• Erythema
• Warmth
• Swelling

Stage II

• Serous

blister/bullae

• Fluctuance
• Woody

induration

• Antibiotic failure

Stage III

• Hemorrhagic

bullae

• Skin anesthesia
• Crepitus
• Skin necrosis
• Duskiness
• Gangrene

Increasing systemic toxicity

Wong CH et al. Crit Care Med. 2004 Jul;32(7):1535-41.

LRINEC score

Incorporates CRP , WBC, Hb, Cr, Na, glucose Score ≥ 6: PPV 92% (95% CI, 84-96), NPV 96% (95% CI, 93-98). Can help in cases where clinical suspicion is equivocal Should NOT replace clinical judgement

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Anaya DA and Dellinger EP. Clin Infect Dis. 2007 Mar 1;44(5):705-10.

Other diagnostic modalities

Xray: Gas=Sp, not Sn CT: Can evaluate for abscess MRI: Can be helpful but slow Frozen section @ bedside: requires Path presence If high suspicion àdo not delay surgery

Stevens DL et al. CID 2014; 59(2), e10–e52

Necrotizing infection microbiology

Monomicrobial (type II)

• S. pyogenes
• S. aureus
• V. vulnificus
• A. hydrophila

Clostridium spp Anaerobic strep spp. (Peptostreptococcus) Polymicrobial (type I) GI/GU/perianal source Incl Fournier’s gangrene Decubitus ulcers IDU injection sites

Stevens DL et al. CID 2014; 59(2), e10–e52 Anaya DA and Dellinger EP. Clin Infect Dis. 2007 Mar 1;44(5):705-10. Kadri SS et al. Clin Infect Dis. 2017 Apr 1;64(7):877-885. doi: 10.1093/cid/ciw871. Darenberg J et al. Clin Infect Dis 2003 37 333 40

Management

Source control

• Without it, mortality close to 100%
• Aggressive debridementàbetter outcomes

Antibiotics

• Until 48-72h after source control
• Cover MRSA, GNRs, anaerobes
• Clinda if GAS or clostridium

Zimbelman J et al. Pediatr Infect Dis J. 1999 Dec;18(12):1096-100. Carpetis JR et al. Clin Infect Dis. 2014 Aug 1;59(3):358-65. doi: 10.1093/cid/ciu304 Andrenoi F et al. J Infect Dis. 2017 Jan 15;215(2):269-277. doi: 10.1093/infdis/jiw229. Linner A et al. Clin Infect Dis. 2014 Sep 15;59(6):851-7. doi: 10.1093/cid/ciu449. Epub 2014 Jun 13.

GAS/toxic shock

§

Most often with invasive GAS infection, including nec fasc

§

Same principles of source control and supportive care

§

Definitive therapy: Penicillin PLUS clindamycin

• At high inocula, beta-lactams may be less effective
• CLI is a protein-synthesis inhibitor, may ↓virulence factors
• Retrospective peds study: 83% vs. 14% “favorable” outcome with CLI + beta-

lactam vs. beta-lactam alone (p < 0.01)

• Prospective surveillance for iGAS in large population in Australia: CLI pts had

more severe dz but ↓ mortality (OR 0.28, 0.01-0.8)

• Swedish prospective surveillance, lack of CLI = OR for death 8.6 (p = 0.007)

§

Some support for IVIG but mixed results and not convincing

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Outline

ü Cellulitis ü Necrotizing infections § Special populations and exposures § Abscess

Lopez FA, Sanders CV. Infect Dis Clin North Am. 2001 Jun;15(2):671-702, xi.

DDx for SSTI in immunocompromised hosts

§ Infection

• Bacterial (usual gm+,

GNRs—ecthyma gangrenosum, Nocardia)

• Fungal (molds, candida,

histo, crypto)

• NTM, TB
• Viral (VZV, HSV)
• Crusted scabies

§ Noninfectious

• Sweets
• Leukemia cutis
• GVHD
• Erythema nodosum
• Pyoderma gangrenosum
• Drug reaction

SSTI management in immunocompromise

§ Dx:

• Dermatology consultation with biopsy
• Fungal markers

§ Rx:

• Prompt empirical therapy: anti-MRSA and broad-

spectrum GNR coverage is appropriate

• +/- anti-fungal coverage based on host + morphology

SSTI association with exposures

Exposure/population Organism Cat bite Pasteurella multocida Human bite Eikenella corrodens, viridans group Strep Dog bite Capnocytophaga, Pasteurella Rat bite Streptobacillus moniliformis Hot tubs Nontuberculous mycobacteria, Pseudomonas Brackish water, cirrhosis Vibrio vulnificus and other species Fresh water Aeromonas Fish/fish tanks Mycobacterium marinum, Erysipelothrix rhusiopathiae

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Stevens DL et al. CID 2014; 59(2), e10–e52

Bites

§

Follow routine wound care, including irrigation

• Discuss rabies vaccine with local health department
• Tetanus vaccine if prior vaccination > 10y ago (clean) or > 5y ago (dirty)

§

Decision to prophylax with antibiotics based on:

• Host factors: Immunocompromised/asplenic/cirrhotic/DM
• Injury mechanism: Severe/deep, location (hand, face, joint), cat>dog (sharp teeth)

§

Drug of choice: amoxicillin/clavulanic acid x 3 days

• Severe β-lactam allergy: TMP/SMX or FQ + clinda (human and dog) or

doxycycline + clinda (cat)

• Severe infection: Consult with ID, many IV options are active

Stevens DL et al. CID 2014; 59(2), e10–e52 Perl B et al. CID 1999; 29(6): 1483-1488

Some other cellulitis points

§ Blood cultures usually unnecessary

• At one center, only 11/710 (2%) of Bcx sent for cellulitis yielded a

pathogen (73% strep) with contaminants in 20/710 (4%)

• Exceptions: Immunocompromised, bites, immersion, surgical

debridement needed

§ Elevate the affected area aggressively § Search for onychomycosis and treat § Treat anatomic factors like edema, eczema

Stevens DL et al. CID 2014; 59(2), e10–e52

Nonpurulent cellulitis summary

MRSA risk factors:

• Unstable
• Device-assoc
• MRSA colonization
• Recent MRSA ifxn
• Hospital exposure (dialysis, LTCF)
• Injection drug use
• Lack of response to a regimen not

covering MRSA

Jenkins TC et al. Clin Infect Dis 2010; 51(8): 895-903

Real-world opportunities

0% 20% 40% 60% Cellulitis Absce ss Complica ted infection

N = 322

GNR coverage rarely needed:

• 150 (47%) had + Micro
• 97% Staph or Strep
• Aerobic GNR coverage: 231 (72%)

Duration can be shortened:

• Median duration: ~2 weeks

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Cellulitis pathways can help improve rx

Yarbrough PM et al. J Hosp Med 2015; 10(12: 780-6

Cellulitis pathway outcomes

59% (71% to 41%) ↓ broad-spectrum abx 44% (52% to 35%) ↓ lab costs Similar LOS and 30d readmissions

Yarbrough PM et al. J Hosp Med 2015; 10(12: 780-6

Outline

ü Cellulitis ü Necrotizing infections ü Special populations and exposures § Abscess

Case #2. 32 y/o F presents with a “spider bite” on her L thigh. You examine her and note a 3 cm abscess with minimal surrounding erythema so perform an I+D in your office and send the material for culture. She is otherwise healthy, has no allergies, and is hemodynamically stable. What would you like to do next?

• A. Observation only with clinical follow-up in 7 days
• B. TMP/SMX 1 DS tab po twice daily x 5 days
• C. TMP/SMX 1 DS tab po twice daily x 10 days
• D. Clindamycin 300 mg po three times daily x 5 days
• E. Clindamycin 300 mg po three times daily x 10 days

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Antibiotics for abscess? Con

376 pts w/ 450 infections undergoing drainage

~60% associated with IV drug use

259/284 (91.2%) of MRSA cultures and 4/157 (2.5%) MSSA cultures got inappropriate antibiotics Failure = persistence of infection requiring further treatment Failure: 2/166 (1.2%) appropriate vs 1/242 (0.4%) inappropriate rx Loss to f/u: 33/441 (7.5%)

Paydar KZ et al. Arch Surg. 2006;141(9):850-856. doi:10.1001/archsurg.141.9.850

Antibiotics for abscess? Pro #1

1247 ED patients w/ abscess requiring drainage

Multicenter, double-blind, placebo-controlled superiority RCT

Placebo TMP/SMX 2 DS tabs BID

Population TMP/SMX Placebo Diff (95% CI) mITT 80.5% 73.6% 6.9% (2.1 to 11.7) Additional surgical drainage 8.0% 13.0%

• 4.9% (-8.8 to -1.1)

Hospitalization 3.6% 6.4%

• 2.8% (-5.6 to 0.1)

New ifxn @ diff site 10.9% 19.1%

• 8.3% (-12.7 to -3.8)

Talan DA et al. N Engl J Med 2016; 374:823-832 Daum RS et al. N Engl J Med. 2017 Jun 29;376(26):2545-2555. doi: 10.1056/NEJMoa1607033.

Antibiotics for abscess? Pro #2

Population Clinda (266) TMP/SMX (263) Placebo (257) ITT 83.1% (78.3-87.9) 81.7% (76.8-86.7) 68.9% (62.0-74.9) SA isolated 83.5% (77.9-89.1) 83.2% (77.5-89.0) 63.8% (56.0-71.5) No SA isolated 83.8% (74.3-93.3) 81.9% (72.4-91.5) 83.1% (74.5-91.8) Adverse event 21.9% 11.1% 12.5%

N = 786 w/ skin abscess ≤ 5 cm

§

Staph aureus present in 67% (74% of those MRSA)

Cellulitis Abscess TMP/SMX Clindamycin

10 days

Antibiotics for abscess? Pro #3

Miller LG et al. N Engl J Med 2015; 372:1093-1103

Abscess: 30.5%, cellulitis: 53.4%, both:15.6% Drainage done in 44.5%

Superiority: Clinical cure

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Pro #3 results: TMP/SMX okay, maybe even for cellulitis

Population Clinda (264) TMP/SMX (260) Diff ITT 80.3% 77.7%

• 2.6% (-10.2 to 4.9)

Cellulitis alone ITT 80.9% 76.4%

• 4.5% (-15.1 to 6.1)

Abscess alone ITT 78.8% 80.0% 1.3% (-12.9 to 15.4) Mixed ifxn ITT 83.0% 80.0%

• 3.0% (-23.0 to 17.0)

Clinda-R MRSA 73.3% 91.7% p = 0.06

Miller LG et al. N Engl J Med 2015; 372:1093-1103

Summary of antibiotics for abscess

§ Most people (>70%) will get better without antibiotics § Antibiotics add a quantifiable benefit § TMP/SMX and clinda both reasonable options

• More clinda resistance
• More GI intolerability with clinda

§ Patient-centered decision-making about antibiotics appropriate

Case, con’t. You drain your patient’s abscess and provide tmp/smx x 10 days. She does well. At her follow-up visit 6 months later, she mentions she has been to the ED three more times to have small abscesses drained. She has grown MRSA when cultured. Besides careful attention to cleaning personal hygiene items and surfaces around the house, she wants to know if there’s anything she can do to prevent further infections?

• A. Doxycycline and rifampin x 10 days
• B. Mupirocin ointment to nares and chlorhexidine baths for 10 days
• C. TMP/SMX x 5 days monthly x 3-6 months
• D. Dilute bleach baths x 3 months
• E. Mupirocin ointment to nares and chlorhexidine baths x 10 days

for her and all family members

Stevens DL et al. CID 2014; 59(2), e10–e52 Liu C et al. Clin Infect Dis. 2011 Feb 1;52(3):e18-55. doi: 10.1093/cid/ciq146. Epub 2011 Jan 4.

Recurrent MRSA SSTI workup

§

Same anatomic siteàis there a local defect? (e.g. pilonidal cleft cyst, hidradenitis suppurativa)

§

Screening for HIV, DM, injection drug use

§

Recurrent infections at a young age or recurrent severe/deep infectionsàimmunological w/u

• Granulocyte disorders: CBC/diff, neutrophil function testing (CGD)
• Quantitative immunoglobulins (hyper IgE syndrome)
• Lymphocyte subsets

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Liu C et al. Clin Infect Dis. 2011 Feb 1;52(3):e18-55. doi: 10.1093/cid/ciq146. Epub 2011 Jan 4. Creech B, Al-Zubeidi DN, and Fritz S. Infect Dis Clin North Am. 2015 Sep; 29(3): 429–464.

Recurrent MRSA SSTI management

§ Clean surfaces that contact affected skin

• More info: https://www.cdc.gov/mrsa/community/environment/index.html

§ Cover infected skin/draining wounds § Do not share personal items (razors, towels, bottles of

lotion, etc.)

§ Launder linens at least weekly, towels more frequently

Decolonization options

(limited data)

§ Mupirocin 2% nasal BID x 5-10 days § Mupirocin 2% x 5-10 days + chlorhexidine 4% baths x 5-10 days § Dilute bleach baths (1/4 cup per 1/4 tub) twice weekly x 3 mths § Retapamulin 1% nasal BID x 5 days § PO TMP/SMX or doxycycline PLUS rifampin x 5-10 days

Stevens DL et al. CID 2014; 59(2), e10–e52 Liu C et al. Clin Infect Dis. 2011 Feb 1;52(3):e18-55. doi: 10.1093/cid/ciq146. Epub 2011 Jan 4. Fritz FA et al. Clin Infect Dis. 2012 Mar;54(6):743-51. doi: 10.1093/cid/cir919.

Household eradication

§ Open-label RCT of 183 children with MRSA or MSSA SSTIs

(healed) and ongoing colonization

• All got mupirocin and chlorhexidine x 5 days
• Families randomized to also get treated or not

§ Results: No significant diff in eradication @ any time point

• Household group: fewer recurrent SSTIs @ 3 months (28% vs

47%; P = .02), 6 months (38% vs 61%; P = .008), and 12 months (52% vs 72%; P = .02)

• Household contacts also had fewer SSTIs

Fritz SA et al. Infect Control Hosp Epidemiol. 2011 Sep;32(9):872-80. doi: 10.1086/661285.

Bleach is an inexpensive alternative

§ Open-label RCT of 300 pts with CA-SSTI and SA colonization

(~45% had recurrent SSTI)

• 1. Hygiene education only
• 2. Education + mupirocin x 5 days
• 3. Education + mupirocin + CHG washes x 5 days
• 4. Education + mupirocin + bleach washes (1/4 cup/bath) x 5 dd

§ Results (1 vs. 2, 3, and 4):

• 1 mth eradication: 38% vs. 56% (0.03) vs. 55% (0.05) vs. 63% (0.006)
• 4 mth eradication: 48% vs. 56% (0.4) vs. 54% (0.51) vs. 71% (0.02)
• Recurrent SSTI in 20% @ 1 mth, 36% @ 4 mths, 49% @ 6 mths, no

difference by arm

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Creech B, Al-Zubeidi DN, and Fritz S. Infect Dis Clin North Am. 2015 Sep; 29(3): 429–464.

Topical antibiotic resistance

§

Mupirocin resistance: 2.5%-15% of CA-MRSA

§

Chlorhexidine resistance: 1-17% or CA-MRSA

§

Resistance to retapamulin also reported

§

Genes for resistance carried on plasmids, which can confer resistance to systemic antibiotics

§

Stewardship of topical antibiotics should not be overlooked

Approach to recurrent Staph infections

Creech B, Al-Zubeidi DN, and Fritz S. Infect Dis Clin North Am. 2015 Sep; 29(3): 429–464. Stevens DL et al. CID 2014; 59(2), e10–e52

Purulent cellulitis summary

Thank you! Questions?

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