Bacterial Infections. Ron Rapini MD Chernosky Chair Dept Dermatology Professor of Pathology Univ of Texas and MD Anderson Cancer Cntr Houston, Texas

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1 Bacterial Infections Ron Rapini MD Chernosky Chair Dept Dermatology Professor of Pathology Univ of Texas and MD Anderson Cancer Cntr Houston, Texas

2 Conflict of interest statement: Book royalties- Elsevier Also no stock in grocery stores that sell Rapini

3 Many of the systemic bacterial infections are more likely to be picked up on blood culture than on skin biopsy Send skin biopsy for culture in sterile cup with moist sterile saline on gauze, not floating in liquid AFB, fungus, bacteria Get blood cultures Fungi more likely to be present on skin biopsy rather than in the blood

4 Blood cultures results are faster nowadays Our hospital: Gram stain of positive culture Verigene (rapid PCR) 3 hours If Verigene neg, then MALDI (matrixassisted laser desorption/ionization) uses mass spectra to indentify Then final identification and antibiotic susceptibilities in 3 to 5 days.

5 Bacterial colonization not infection Don t just swab specimens if systemic infection

6 Fat necrosis with bacteria MRSA and Pseudomonas

7 Rashes at the hospital most are one of five things 1. Drug rash 2. Infection 3. Reactive to something else (vasculitis, blood products, contact, tumor antigens, unknown) 4. Leukemia, lymphoma, solid tumor in skin 5. Graft-vs-Host disease

8 INFECTIONS not always as they seem

9 Cellulitis-like leg edema from gemcitabine (Gemzar)

10 Vasculitis causes Infection (hepatitis C, fungus) Connective tissue disease (lupus, cryoglobulinemia, etc) Drug Idiopathic

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13 Candida sepsis GMS stain of yeast

14 Purpura, especially palpable always consider fungus but can also be bacteria

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16 Meningococcemia!

17 Vasculitis Xeloda(capecitabine)

18 Staph septic vasculitis

19 Beta-hemolytic streptococcal vasculitis

20 Gram negative vasculitis

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22 Streptococcus viridans endocarditis

23 Morbilliform = maculopapular = exanthematous The most common type of (1) drug rash Resembles (2) viral eruptions and secondary (3) syphilis Usually less dangerous than urticarial eruptions or vasculitis

24 Drug NOT infection

25 Secondary syphilis

26 Forearm ulcer after local trauma in Mexico DP

27 DP

28 DP Gram stain

29 DP GMS

30 Nocardia asteroides Nocardia braziliensis Pulmonary, CNS, Skin Gram+, GMS+, AFB+ Sulfur granules sometimes Grows is 2-5 days in blood agar or routine culture, but lab has to hold it longer Aerobic, unlike Actinomyces

31 Nocardiosis Primary innoculation nonsystemic form often resolves spontaneously Trimethoprim-sulfamethoxazole DS bid for 2 to 4 weeks F/U on this case healed readily with above Rx

32 Disseminated nocardiosis

33 A papulosquamous eruption psoriasis?

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38 Eosinophils is it drug?

39 Lymphocytes plasma cells

40 Differential diagnosis? What definitive tests?

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43 Warthin-Starry spirochete

44 Spirochete immunostain is about 80% reliable

45 Secondary syphilis histologic patterns Perivascular Psoriasiform Lichenoid Granulomatous Interstitial granulomatous dermatitis Vasculitis ( lues maligna )

46 Plasma cells Common on mucous membranes, including perinasal Infectious diseases Morphea Lyme disease Folliculitis 1 / 3 of secondary syphilis cases: no plasma cells

47 Secondary syphilis usually is NOT Usually NO pruritus Usually NO eosinophils (like LE) Usually NOT vesicular in adults

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53 Secondary syphilis Not a zebra everyone knows about it, not just for syphilologists Just a reminder that if you re not seeing it much, you probably are missing it Either the clinician or the pathologist has to think of it I initially missed the one that looked like interstitial GA with no plasma cells

54 Syphilis - palms

55 Granulomatous late secondary syphilis

56 Lues maligna = syphilitic vasculitis

57 Patient was found in a Houston park, inebriated, lying on a fire ant hill

58 Fire ant pustules with pseudomonas superinfection

59 Rapini R, Ralston J: Fire ant stings

60 Stasis ulcer with pseudomonas

61 Pseudomonas

62 Zebra vs horse: Lumpy jaw (actinomyocis)? Actually was Staph aureus Common things are common

63 Actinomycosis sulfur granule

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65 Dental sinus tract need dentist

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67 Abscess with osteomyelitis

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69 SSSS = Staph scalded skin syndrome

70 Staph scalded skin syndrome

71 SSSS

72 Need stat frozen section for SSSS vs TEN per some books? Usually you can tell just by walking in the room SSSS usually young children, not so much in adults unless renal insufficiency If you need biopsy, you can just roll up some of the peeling skin into a ball and submit as biopsy rather than cutting the patient

73 TEN

74 Infectious cellulitis

75 Patient with hand eczema!

76 Patient with hand eczema! had red streak of lymphangitis

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78 Cellulitis abscess - Staph

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80 Erysipelas usually strept

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82 Erysipeloid in a meat packer

83 Erysipelothrix rhusiopathiae If localized, may be self-limited Some patients have systemic symptoms and it can disseminate endocarditis, etc Rx penicillins, cephalosporins, ceftriaxone Resistant to vancomycin

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85 Syphilitic alopecia had NO RASH!

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87 Syphilis more often annular with darker skin types

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89 Gonococcemia (with arthritis) - more likely to find organism in genital area

90 Gonoccocemia necrotic pustule

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92 Meningococcemia

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94 Ecthyma gangrenosum = pseudomonas sepsis

95 Ecthyma gangrenosum (pseudomonas)

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