SKIN AND SOFT TISSUE INFECTIONS ZAIN CHAGLA SEA COURSES - PATAGONIA
COPYRIGHT 2017 BY SEA COURSES INC. All rights reserved. No part of this document may be reproduced, copied, stored, or transmitted in any form or by any means graphic, electronic, or mechanical, including photocopying, recording, or information storage and retrieval systems without prior written permission of Sea Courses Inc. except where permitted by law. Sea Courses is not responsible for any speaker or participant s statements, materials, acts or omissions.
AGENDA Cutaneous mycosis Cellulitis Boils and abscesses Diabetic foot infections Rash Trivia!
CASE 1 70 year old diabetic male Presents with fever, malaise, acute left leg pain and redness On exam 38.1, mild pain on palpation, otherwise normal exam
SKIN AND SOFT TISSUE INFECTIONS Huge morbidity particularly in outpatient settings Diagnostic conundrums Further testing In inpatient -? Necrotizing infection Non resolution Recurrence Although single entities - there can be overlap or one causing the other Ex - Athletes foot leading to cellulitis
CUTANEOUS MYCOSIS Very common in practice Lots of cosmetic morbidity, some significant Affects young to old
MANAGEMENT If possible can send skin scrapings - take the back of a scalpel and brush the scrapings onto back filter paper and send to lab Fungi is subsequently cultured / Ided Certain bugs respond better to certain topical therapies If not cultured then consider topical Miconazole, Ketoconazole, Clotrimazole Terbinafine as second line Should respond in 4-6 weeks If non response get cultures and consider derm referral or systemic(terbinafine or Iitraconazole) with liver enzyme monitoring
MIMICKERS
ERYTHRASMA Corynebacterium infection of skin Wood lamp Coral red Can send skin scrapings for gram stain to confirm Treat: Topical Clinda or Fuscidin, Macrolide, oral imidazole (miconazole)
MIMICKERS
NUMULAR / DISHYDROITIC eczema Treat with topical steroids
SUMMARY Cutaneous mycosis common Treat with topical Skin scrapings for fungal and gram stain If not responding - think of a mimicker or re-sample Derm referral +/- systemic therapy if high suspicion of fungal
Furuncle Impetigo carbuncle
IMPETIGO Easy to diagnose and treat Topical vs. systemic not particularly different Staph and strep predominantly
BOILS AND ABSCESSES Do you need systemic treatment? Controversial Early studies (prior to MRSA era) suggested incision and drainage alone similar to placebo Post MRSA era small studies showed no difference Duong M, et al. Ann Emerg Med. 2010. -- 162 children Schmitz GR, et al. Ann Emerg Med 2010 -- 212 adults Talan et al. NEJM 2016 used a fairly large study (1265 patients) > 12 year olds, with clinical failure defined as worsening day 3-4 (size, induration, systemic symptoms) Septra vs. Placebo
INTERPRETATION May need to consider septra for abscesses particularly in high MRSA settings (around 45% of the trial population) Still unclear if benefit is antimicrobial activity vs. anti-inflammatory activity of the antimicrobials (clinical outcome was mainly symptom derived)? Some protection for household contacts Consider if no contraindications a course of TMP-SMX Allergic and MSSA - Keflex, Clavulin Allergic and MRSA - Clindamycin (Some risk of failure), Linezolid, doxycycline, vancomycin, once weekly injectables
Erysipelas Cellulitis
CELLULITIS Non purulent vs Purulent / ulcer Non purulent / most ulcer related are typically streps Group A, Group C, occ Group B/G Even in patients with MRSA Treat with cefazolin or cephalexin, clindamycin if REALLY allergic Purulent cellulitis Usually staph - consider I+D plus antimicrobial therapy as above, Septra or Clinda if MRSA Non resolution - leg redness / edema may persist for weeks, check for position, consider compression Look for mimickers - venous stasis, candida, allergic reactions Recurrence - look for nidus (nails, candida, ulcer) For MRSA in healthy outpatients - refer to ID eventually for decolonization
SUMMARY Purulent skin and soft tissue infections Predominantly STAPH - consider I+D and secondary therapy Non purulent SSTI Cellulitis vs. Erysipelas Treat with beta lactam Watch for mimickers / non resolvers Consider nidus of infection
CASE 2 You are seeing the same patient 3 months later In interim, poor sugar control, diabetic neuropathy Developed a 1 st MTP ulceration on the first toe secondary to a new pair of shoes Started 3 weeks ago Covered with a band aid Now purulent with surrounding erythema You swab it and start antibiotics, and send off a foot Xray Report No osteolytic changes - cannot rule out osteomyelitis, consider bone/wbc scan Bone scan shows reactive changes in the 5 th MTP
ULCERS More complex Particularly in legs interplay between vascular, infection, neuropathy Not all ulcers need to be treated - only foul smelling, erythema, pus, induration Don t swab anything that isn t infected - there will be bacteria in it Good examination including vascular/neuropathy and depth/probing Treat based on duration Keflex / Clinda if acute (<2 weeks) Consider adding fluoroquinolone if chronic Duration until it looks non infected - not necessarily re-epithelization Wound care and optimization of other risk factors (sugars, offloading, mobility if on sacrum)
OSTEOMYELITIS Consider in adults if wound looks close to bone or recurrence of ulcer infection repeatedly despite therapy For continuous osteomyelitis (i.e. diabetic feet) the infection needs to go through all layers to get to bone - therefore superficial ulcers cannot be osteomyelitis Should I order further testing When bone exposed and dirty wound - this is OM, no need to test further When very superficial wound/responded to therapy - no need to test further In a deepish wound close to bone or recurrence after therapy - consider Pre-test probability of 25-75%
WHAT TO ORDER? Likelihood ratio WBC scan (+) 2.6, (-) 0.235 Bone scan (+) 1.1, (-) 0.72 MRI (+) 9, (-) 0.11 Bottom line - Order the testing if you re unsure - Start with an Xray - If you re still unsure move on to MRI - If MRI contraindicated then consider bone/wbc scan - ONLY consider osteomyelitis if it lights up where the ulcer is - Be prepared for false positives
WHEN TO REFER Osteomyelitis (most) Recurrent cellulitis All hematogenous or traumatic non diabetic osteomyelitis (dog / cat bites) Still consider trying treatment as still is usually 2-4 weeks minimum wait Bony uptake of quinolones, septra, and clindamycin are high
SUMMARY Evaluate the wound base If superficial treat until resolution of infectious changes If deep try to probe to bone If probable stop workup If unclear order Xrays then MRI Avoid bone scans unless necessary Treat with fluoroquinolones, septra, parenteral B-lactams
RASH TRIVIA
Stasis Dermatitis or Chronic Venous Insuffiency -Bilateral (rare in cellulitis) - Edema + chronic changes -Painful / inflammatory -sometimes associated HF -can occasionally become superinfected but one side -Tx - mobilize fluid, stockings, diuresis
Varicella vesicles at different ages intensely pruritic Dewdrop on a leaflet AIRBORNE PRECAUTIONS Dx - unroof - culture/pcr Tx - Valtrex/Acyclovir if early!