1. Kurt A. Wargo, Pharm.D., BCPS (AQ-ID) Associate Clinical Professor Auburn University Harrison School of Pharmacy Fall CE Program November 6, 2011 Management of Skin and Skin Structure Infections (SSSIs)

2. Disclosure I have nothing to disclose, no potential or actual conflicts of interests exist

3. Objectives Identify common pathogens Link symptoms to pathogens Determine antibiotics effective against common pathogens Become familiar with bioterrorism threats Develop treatment plans Presentation developed from: Clinical Infectious Diseases 2005; 41:1373–406

4. Necrotizing infections Rapidly progressing infections Patients show systemic signs: Fever Hypotension Tachycardia Elevated white blood cells Impetigo Erysipelas Cellulitis Abscesses Patients have very little to no systemic signs Uncomplicated vs. Complicated SSSIs Uncomplicated SSSIsComplicated SSSIs

5. Uncomplicated SSSIs Organisms – S. aureus / MRSA Definite area of induration Furuncles, carbuncles, or abscesses “If you see pus, think Staph!” – Group A Streptococci No defined area of induration Extensive erythema and warmth http://www.gslabs.com/photomicroscopy.html http://bioweb.uwlax.edu/bio203/s2007/falk_pete/identification.htm

6. Categories of Uncomplicated SSSIs Impetigo Erysipelas Cellulitis Abscesses Bioterrorism threats

7. Impetigo Characteristics: Consists of several purulent lesions, usually on face and exposed areas of skin Occurs most frequently among economically disadvantaged children in tropical or subtropical regions Also prevalent in northern climates during the summer months Caused by Staphylococcus aureus or Streptococcus pyogenes (Group A Strept) http://drugster.info/ail/pathography/105/

8. Treatment of impetigo Systemic or topical antibiotics that target Streptococcus and Staphylococcus for 7 days Clindamycin ± Sulfamethoxazole/trimethoprim Amoxicillin/clavulanate, dicloxacillin, and cephalexin if MRSA is not suspected Topical Mupirocin TID

9. Erysipelas and Cellulitis Terms used interchangeably Both have the following characteristics: Rapid spreading Edema Erythema Warmth

10. Extends into deeper tissue (involves dermis and subcutaneous tissue) Skin may resemble an orange peel due to edema around hair follicles causing skin dimpling Can be anywhere on the body Caused by Streptococcus, Group A and Staphylococcus Involves epidermis Lesions are raised above the level of the surrounding skin Clear line of demarcation between involved and uninvolved tissue Usually on face and extremities Most commonly caused by Streptococcus, Group A Erysipelas versus Cellulitis Erysipelas Cellulitis

11. ErysipelasCellulitis http://www.the-hospitalist.org/details/article/262691/What_is_the_best_empiric_therapy_for_community- acquired_cellulitis.html http://www.sciencephoto.com/image/256250/530wm/M1500109- View_of_reddening_due_to_erysipelas_on_womans_face-SPL.jpg

12. Risk Factors for Cellulitis and Erysipelas Skin breach Fungal infections Prior skin infection (impetigo) Spider bites Eczema Surgery Fragile skin / host defense ineffective Obesity Venous insufficiency Lymphedema

13. Special Situations Animal (Dogs / Cats) Bites Pasteurella multocida and Capnocytophaga canimorsus (gram negative rods) Spider Bites (Brown recluse or Black widow) MRSA Fresh water Aeromonas hydrophila (gram negative rod) Salt water Vibrio vulnificus (gram negative rod) Periorbital cellulitis Haemophilus influenzae (gram negative rod)

14. Community-Acquired MRSA MRSA now a threat in the community Characterized by production of toxins (PVL) that lyse WBCs and cause areas of skin necrosis Hospital-acquired isolates tend to be more resistant to antibiotics than CA-MRSA Known risk factors: Children Participants of contact sports Prisoners IV drug users MSM

15. Huntsville Hospital MRSA Data Year % MRSA inpatient % MRSA ED 200248NR 200348NR 200456NR 200555NR 200661NR 20076379 20086275 20096075 20105666

16. Bioterrorism Threats Anthrax Bubonic Plague Tularemia

17. Anthrax (Bacillus anthracis) Gram-positive, spore-forming, rod After exposure, there is an incubation period of 1–12 days Pruritus begins at the entry site, followed by a papule, development of vesicles on top of the papule, and, finally, a painless ulcer with a black scab This eschar generally separates and sloughs after 12–14 days Swelling surrounding the lesion can be minor or severe Mild-to-moderate fever, headaches, and malaise often accompany the illness. http://textbookofbacteriology.net/Anthrax.html

18. Cutaneous Anthrax http://bepast.org/docs/photos/anthrax/Cutaneous anthrax with ulceration.jpg

19. Bubonic Plague (Yersinia pesitis) Facultative, anaerobic, gram-negative coccobacilli Primarily affects rodents and their fleas Three plague syndromes occur in humans: septicemic, pneumonic, and bubonic Bubonic plague develops when humans are bitten by infected fleas or have a breach in the skin when handling infected animals Domestic cat scratches or bites may also transmit bubonic plague Patients usually develop fever, headache, chills, and tender regional lymphadenopathy (buboes) 2–6 days after contact with the organism A skin lesion at the portal of entry is sometimes present

20. Bubonic Plague http://en.wikipedia.org/wiki/File:Yersinia_pestis. jpg http://science.howstuffworks.com/ environmental/life/zoology/insects- arachnids/flea3.htm

21. Tularemia (Francisella tularensis) Gram-negative coccobacillus Transmitted via ticks; rodents and rabbits serve as the reservoir After being bitten, there is an incubation period of 3–10 days The skin lesion (an ulcer or an eschar) will develop at the entry site of the organism, along with tender regional adenopathy in the lymph nodes (ulceroglandular) In some patients, the skin lesion is inconspicuous or healed by the time that they seek medical care, resulting in “glandular” tularemia The illness is often associated with substantial fever, chills, headache, and malaise

22. Tularemia http://www.healthy.arkansas.gov/programsServices /infectiousDisease/zoonoticDisease/Pages/Tick- BorneDisease.aspx http://www.upmc- biosecurity.org/website/our_work/biological-threats- and-epidemics/fact_sheets/tularemia.html

23. Treatment of SSTIs 1.Incision and Debridement (if area of induration) 2.Antibiotics a.If S. aureus suspected, TREAT MRSA: Clindamycin 300 mg PO q8h + TMP/SMX 2 DS PO BID suspected b.If Group A Streptococcus suspected: a.The world… b.Cephalosporins, Clindamycin, Tetracyclines, Levofloxacin

24. Antimicrobial options Infection (Organism)Outpatient AntibioticAdult Dosage Impetigo, Erysipelas (Group A Strept) Cephalexin250 – 500 mg PO q6h Clindamycin300 – 450 mg PO q8h Amox/Clav875/125 mg PO q12h Mupirocin ointmentApply to lesions q8h Cellulitis (S. aureus - MRSA) Clindamycin300 – 450 mg PO q8h TMP/SMX2 DS tablets PO q12h Doxycycline100 mg PO q12h Linezolid600 mg PO q12h Animal Bites (Pasteurella multocida and Capnocytophaga canimorsus) Amox/Clav875/125 mg PO q12h

25. Antimicrobial options for Bioterrorism Infection (Organism)Outpatient TreatmentAdult Dosage Anthrax (Bacillus anthracis) Doxycycline100 mg PO q12h Ciprofloxacin500 mg PO q12h Bubonic Plague (Yersinia pestis) Streptomycin1 g IM q12h Doxycycline100 mg PO q12h Ciprofloxacin500 mg PO q12h Tularemia (Francisella tularensis) Doxycycline100 mg PO q12h Ciprofloxacin750 mg PO q12h

26. Approach to the patient with SSSIs 1.Look at the skin 2.Get a good history of the patient PMH Exposures / bites 3.Decide if you think it is infected 4.Call the MD if you have a recommendation or refer the patient

27. Name That Bug…

32. A patient with no past medical history presents to your pharmacy after stating he had a recent spider bite on his leg that he thinks is infected. Upon examination, you see that the wound looks to be red and is draining pus. 1.What is the most likely organism? a.Staphylococcus aureus b.Group A Streptococcus c.Francisella tularensis d.Yersinia pesitis

33. A patient with no past medical history presents to your pharmacy after stating he had a recent spider bite on his leg that he thinks is infected. Upon examination, you see that the wound looks to be red and is draining pus. 2.What would be the most appropriate antimicrobial therapy to recommend to the physician? a.Ciprofloxacin 500 mg PO q12h b.Amox/Clav 875/125 mg PO q12h c.TMP/SMX 800/160 mg 2 tablets PO q12h d.Streptomycin 1 g IM q12h

34. A woman comes to your pharmacy in Orange Beach complaining of an infection on her leg. Upon questioning her, you find out she was swimming in the gulf and “rubbed up against something.” As you inspect the leg you see that it clearly looks infected and you tell her to go directly to the hospital. 3.What is the most likely cause of the infected leg? a.Bacillus anthracis b.Vibrio vulnificus c.Aeromonas hydrophila d.Group B Streptococcus

35. A man presented to your pharmacy with some redness on his face. He stated it started about 2 days ago, but doesn’t remember anything in particular that happened. As you look at his face you notice there is a clear line of demarcation around his cheek, without any pus. 4.What is the best antimicrobial to treat his infection? a.TMP/SMX b.Ciprofloxacin c.Metronidazole d.Cephalexin

36. Kurt A. Wargo, Pharm.D., BCPS (AQ-ID) Associate Clinical Professor Auburn University Harrison School of Pharmacy Fall CE Program November 6, 2011 Management of Skin and Skin Structure Infections (SSSIs)