Skin, Bone, and Joint Infections - PowerPoint PPT Presentation

1 / 61
About This Presentation
Title:

Skin, Bone, and Joint Infections

Description:

Caused by S. aureus of phage group II (usually type 71) ... A severe reaction to S. aureus strains producing exfoliative toxins ... S. aureus the usual pathogen ... – PowerPoint PPT presentation

Number of Views:614
Avg rating:3.0/5.0
Slides: 62
Provided by: bry978
Category:
Tags: bone | infections | joint | skin

less

Transcript and Presenter's Notes

Title: Skin, Bone, and Joint Infections


1
Skin, Bone, and Joint Infections
  • Charles S. Bryan, M.D.
  • November 26, 2007

2
(No Transcript)
3
Overview of skin infections
  • Pyodermas
  • Secondary bacterial infections complicating
    pre-existing lesions of the skin
  • Skin lesions in septicemias
  • Infectious gangrene, gangrenous cellulitis, gas
    forming infections, and other surgical
    infections

4
Overview of the pyodermas
  • Impetigo
  • Staphylococcal scalded skin syndrome
  • Folliculitis, furuncles, and carbuncles
  • Ecthyma
  • Erysipelas and cellulitis
  • Erythrasma

5
(No Transcript)
6
Non-bullous impetigo
  • Superficial (intraepidermal)
  • Initially vesicular, then becomes crusted
  • Unit lesion intraepidermal, unilocular
    vesicopustule
  • Stuck-on honey-colored crust
  • S. pyogenes (90) also S. aureus
  • Mainly children highly communicable

7
(No Transcript)
8
Ecthyma
  • Begins in the epidermis (like impetigo), but
    penetrates down in to the dermis to form
    punched-out ulcers covered by greenish-yellow
    crusts and surrounded by raised violaceous
    margins
  • Group A streptococci can cause as primary or
    secondary infection
  • See also ecthyma gangrenosum (below)

9
Bullous impetigo
  • Mainly newborn and younger children
  • About 10 of all cases of impetigo
  • Caused by S. aureus of phage group II (usually
    type 71)
  • Exfoliative toxins explain formation of bullae

10
Staphylococcal scalded skin syndrome
  • Younger children can cause epidemics in
    nurseries (pemphigus neonatorum or Ritters
    disease)
  • A severe reaction to S. aureus strains producing
    exfoliative toxins
  • Large, flaccid bullae rupture, causing same
    effect as a third-degree burn

11
(No Transcript)
12
(No Transcript)
13
Folliculitis
  • A pyoderma involving the hair follicles of the
    apocrine regions
  • Small papules evolve into pustules
  • S. aureus the usual cause
  • Pseudomonas aeruginosa (pools whirlpools)
  • Candida species in hospitalized patients
  • Malassezia furfur (diabetes, steroids)

14
Furuncles (boils) and furunculosis
  • Usually arise from folliculitis
  • S. aureus the usual pathogen
  • Some persons have a tendency to develop multiple,
    recurrent furuncles (furunculosis) most are
    chronic nasal carriers of S. aureus but otherwise
    the predisposition is largely unexplained

15
Carbuncles
  • Similar to furuncles but larger, deeper, and more
    extensive
  • Usually at nape of the neck, on the back, or on
    the thighs
  • Usually due to S. aureus
  • Can produce significant systemic symptoms

16
Hidradenitis suppurativa
  • Chronic infections of the apocrine glands in the
    axillae (hidradenitis suppurativa axillary),
    groin (hidradenitis suppurativa inguinalis), or
    perianal lesions
  • Primary lesion probably non-infectious
  • Usually refractory to antibiotic therapy

17
Cellulitis
  • An acute spreading infection involving the dermis
  • Erysipelas is a type of cellulitis involving
    mainly the dermis other forms of cellulitis
    extend to the subcutaneous tissues
  • Most cases are due to S. aureus and/or group A
    streptococci

18
(No Transcript)
19
(No Transcript)
20
(No Transcript)
21
Erysipelas
  • A dramatic, rapidly-spreading cellulitis nearly
    always caused by group A streptococci
  • Lymphangitic streaks and tender regional
    lymphadenopathy
  • Lower extremities in 80 of cases face in 5 to
    20 of cases
  • Tends to recur after first episodes

22
(No Transcript)
23
(No Transcript)
24
(No Transcript)
25
72 y.o. retired nurse
  • CC swelling of left side of face X 1 day
  • One day PTA Sore throat, then swelling of left
    side of face Dx cellulitis, Rx antibiotics
  • Day of admission pain, left side of face with
    further swelling. Fever not a complaint.
  • PMH atrial fibrillation syncopal disorder
    hypertension type I allergy to PCN remote
    history of breast cancer (1991) meds digoxin,
    Lopressor, warfarin, Lasix, ASA

26
On admission
  • NAD uncomfortable
  • Temp. 96.9, BP 97/54 SP02 98
  • WBC 10.2K BUN 19, creatinine 1.8 mg/dL
  • CT scan diffuse swelling, no deep inflammatory
    process, cavernous sinus area OK
  • Rx vancomycin, aztreonam, metronidazole (per
    2007 Sanford guide)

27
Day 2
  • BP dropped to 60 systolic atrial fibrillation
    with rapid ventricular response
  • Transferred to ICU BP quickly restored
    increased neck swelling (sublingual/submandibular)
  • WBC 11.9 K blood cultures sterile
  • Tracheostomy done aspirates of
    submandibular/sublingual spaces no indication of
    abscess

28
Day 3
  • Eye culture from admission group A streptococcus
    (preliminary)
  • Temp. 99.4, BP 87-103/55-72, SP02 92-100
  • WBC 11.4K, platelets 114K
  • Dx Probable early streptococcal toxic shock
    syndrome
  • Rx Clindamycin IVIG

29
Subsequent course
  • Day 4 Improved
  • Day 5 Worse SP02 91-92 on ventilator WBC 18.7
    K, BUN 40, creatinine 1.1, anion gap 21 with
    lactic acid 3.5, AST 300, ALT 208, prothrombin
    time 45.6 seconds
  • Day 6 Expired

30
Unusual causes of cellulitis
  • Aeromonas hydrophila wounds fresh water
  • Vibrio species wounds salt water
  • Erysipelothrix rhusiopathiae salt-water fish,
    meat, poultry, hides
  • H. influenzae young children
  • Cryptococcus neoformans immunocompromised

31
(No Transcript)
32
(No Transcript)
33
Erythrasma
  • A common superficial infection
  • Slowly-spreading, reddish-brown, finely-wrinkled
    macule, often quite pruritic
  • Usually in the genitocrural area, especially men
    who are often obese or who have diabetes
  • Corynebacterium minutissimum coral-red
    fluorescence under Woods light

34
Chronic superficial skin ulcers
  • Decubitus ulcers
  • Diabetic foot ulcers
  • Venous stasis ulcers
  • Classically these become infected with a
    combination of aerobic and anaerobic pathogens
    extensive skin and bone involvement can occur

35
Skin infections in immunocompromised patients
  • Can occur after minor trauma
  • Can be due to virulent pathogens or
    opportunistic pathogens
  • Examples include the less-pathogenic fungi (e.g.,
    Alternaria, Trichophyton, Penicillium),
    mycobacteria, and even algae

36
(No Transcript)
37
Myositis
  • Pyomyositis uncommon usually due to S. aureus
    (95) especially seen in tropics
  • Clostridial myonecrosis (true gas gangrene)
  • Nonclostridial (crepitant) myositis Includes
    anaerobic infections synergistic (mixed)
    infections infected vascular gangrene Aeromonas
    hydrophila infection

38
Septic arthritis overview
  • Incidence 2 to 10 per 100,000 in general
    population but 30 to 70 per 100,000 in patients
    with rheumatoid arthritis and/or joint prostheses
  • Irreversible loss of joint function develops in
    25 to 50 of patients
  • Mortality 5 to 15

39
Septic arthritis overview (2)
  • Usually hematogenous
  • Can result from wounds or from intra-articular
    injection of mediations
  • Predisposing factors trauma endocrine notably
    with gonococcal arthritis underlying joint
    disease

40
Acute bacterial arthritis
  • Usually monoarticular (90)
  • Knee most common (50) then hip
  • Children also ankle and elbow
  • Adults also shoulder, sacroiliac joints,
    sternoclavicular joints

41
Acute bacterial arthritis (2)
  • Children under 2 Haemophilus influenzae
  • Sexually-active adults under 30 N. gonorrhoeae
  • S. aureus important in all age groups most
    common agent in adults 30 usual cause (80)
    with rheumatoid arthritis
  • others Enterobacteriaceae, Pseudomonas sp., S.
    pneumoniae

42
Chronic monoarticular arthritis with
granulomatous histology
  • Mycobacteria
  • Nocardia
  • Sporotrichosis
  • Other fungi
  • Brucellosis

43
Lyme disease and arthritis
  • Months after the onset of late infection, about
    60 of patients who have received no antibiotics
    develop frank arthritis, typically intermittent
    attacks of oligoarticular arthritis in large
    joints.
  • A high percentage of these patients have the
    class II MHA complex allele HLA-DR4

44
Viral arthritis
  • Rubella joint involvement is usually
    polyarticular
  • Mumps polyarticular arthritis
  • Hepatitis B symmetric arthritis related to
    immune complexes
  • Parvovirus B19 in adults pauciarticular
    arthritis with rash
  • HIV disease

45
Whats your diagnosis?
46
Post-infectious arthritis syndrome
  • Reactive arthritis
  • Apparently due to immune complexes
  • Especially common in persons with
    histocompatibility antigen HLA-B27
  • Tends to occur after gastrointestinal symptoms
    with Shigella, Salmonella, Campylobacter, and
    Yersinia

47
(No Transcript)
48
Osteomyelitis (overview)
  • A difficult-to-treat infection characterized by
    the progressive inflammatory destruction and new
    apposition of bone
  • Three clinical types hematogenous osteomyelitis
    osteomyelitis secondary to a contiguous focus of
    infection and osteomyelitis secondary to
    vascular insufficiency

49
Osteomyelitis pathogenesis
  • Normal bone resists infection
  • Certain pathogens, notably S. aureus, adhere to
    bone by expressing receptors (adhesins) for
    components of bone matrix and cartilage.
  • S. aureus can survive intracelluarly in
    osteoblasts

50
Osteomyelitis pathogenesis (2)
  • Normal bone remodeling requires coordinated
    interplay of osteoblasts and osteoclasts
  • Cytokines (e.g., IL-1, IL-6, TNF) are potent
    osteolytic factors
  • Arachidonic acid metabolites (e.g., PGE2 decrease
    the amount of inoculum need to cause infection

51
Osteomyelitis pathogenesis (3)
  • Pus spreads through vascular channels, raising
    intraosseous pressure and impairing blood flow
  • Ischemic necrosis causes separation of
    devascularized fragments (sequestra)
  • Necrotic bone (recognized by absence of living
    osteocytes) is a hallmark of chronic osteomyelitis

52
Osteomyelitis microbiology
  • Salmonella or Streptococcus pneumoniae sickle
    cell disease
  • Coagulase-negative staphylococci or
    Propionibacterium sp. foreign bodies
  • S. aureus most common pathogen
  • Enterobacteriaceae or Pseudomonas aeruginosa
    nosocomial infections

53
Osteomyelitis microbiology (2)
  • Pasteurella multocida animal bites
  • Eikenella corrodens human bites
  • Bartonella henselae HIV disease
  • Aspergillus, Candida albicans, MAC
    immunocompromised patients
  • M. tuberculosis, Brucella, Coxiella burnettii (Q
    fever), and fungi certain high-prevalence
    populations

54
Hematogenous osteomyelitis
  • Usually affects the metaphysis of growing bones
  • The sharp loops formed by nutrient arteries as
    they approach the epiphyseal growth plates
    results in metaphyseal capillaries where blood
    flow is sluggish and phagocytic lining cells are
    absent (afferent loops) or functionally inactive
    (efferent loops)

55
Hematogenous osteomyelitis (2)
  • Most commonly occurs in children, prior to fusion
    of epiphyseal plates in growth ends of long bones
  • In adults, especially over age 50, tends to occur
    in the spine (vertebral osteomyelitis--an
    important and difficult disease to recognize)

56
Hematogenous osteomyelitis (3)
  • S. aureus the most common pathogen. Often there
    is a history of preceding minor trauma, setting
    up a locus minoris resistentiae
  • Other pathogens include streptococci (especially
    neonates), Salmonella species (especially in
    sickle cell disease) and Pseudomonas species (IV
    drug users)

57
Vertebral osteomyelitis
  • Nearly always represents hematogenous
    osteomyelitis
  • Typically involves two adjacent vertebrae and the
    disk space between them
  • Neck or back pain and fever are the main symptoms
  • Physical exam localized spinous tenderness

58
Osteomyelitis due to a contiguous focus of
infection
  • Predispose trauma, surgery, bite wounds,
    puncture wounds
  • Typical patient someone who has had undergone
    ORIF for fracture
  • Often polymicrobial
  • Associations Pseudomonas aeruginosa nail
    puncture Pasteurella multocida animal bites
    anaerobes trauma or decubitus ulcers

59
(No Transcript)
60
(No Transcript)
61
Osteomyelitis associated with vascular
insufficiency
  • Mainly polymicrobial osteomyelitis of the small
    bones of the feet in patients with advanced
    diabetes mellitus and sensory polyneuropathy
    (neuropathy
    --ulcers--bone penetration)
  • On average, 6 bacterial species per case, evenly
    distributed among aerobes and anaerobes
Write a Comment
User Comments (0)
About PowerShow.com