Bacterial Infections Chapter 14

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Bacterial InfectionsChapter 14

• Infections Caused by Gram Positive Organisms.
• Michael Hohnadel, D.O.
• 02/07/2006

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Staphylococcal Infections

• General
• 20 of adults are nasal carriers.
• HIV infected are more frequent carriers.
• Lesions are usually pustules, furuncles or
  erosions with honey colored crust.
• Bullae, erythema, widespread desquamation
  possible.
• Embolic phenomena with endocarditis
• Olser nodes
• Janeway Lesions

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Embolic Phenomena With Endocarditis

Osler nodes
Janeway lesion
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Superficial Pustular Folliculitis

• Also known as Impetigo of Bockhart
• Presentation Superficial folliculitis with thin
  wall, fragile pustules at follicular orifices.
• Develops in crops and heal in a few days.
• Favored locations
• Extremities and scalp
• Face (esp periorally)
• Etiology S. Aureus.

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Sycosis Vulgaris(Sycosis Barbae)

• Perifollicular, Chronic , pustular staph
  infection of the bearded region.
• Presentation Itch/burn followed by small,
  perifollicular pustules which rupture. New crops
  of pustules frequently appear esp after shaving.
• Slow spread.
• Distinguishing feature is upper lip location and
  persistence.
• Tinea is lower.
• Herpes short lived
• Pseudofolliculitis Barbea ingrown hair and
  papules.

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Sycosis Vulgaris
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Sycosis Lupoides

• Etiology Staph. Aureus infection that, through
  extension, results in a central hairless scar
  surrounded by pustules.
• Histopathology Pyogenic folliculitis and
  perifolliculitis with deep extension into hair
  follicles often with edema.
• Thought to resemble lupus vulgaris in appearance.

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Treatment of Folliculitis

• Cleansing with soap and water.
• Bactroban (Mupirocin)
• Burrows solution for acute inflammation.
• Antibiotics cephalosporin, penicillinase
  resistant PCN.

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Furunculosis

• Presentation A perifollicular, round, tender
  abscess that ends in central suppuration.
• Etiology S. Aureus
• Breaks in skin integrity is important.
• Various systemic disorders may predispose.
• Hospital epidemics of abx resistant staph. may
  occur
• Meticulous hand washing is essential.

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Furuncle
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Furuncle / Carbuncle

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Furunculosis

• Treatment of acute lesions
• ABX may arrest early furuncles.
• Incision and drainage AFTER furuncle is localized
  with definite fluctuation.
• No incision of EAC or nasal furuncles. TX with
  ABX.
• Upper lip and nose, danger triangle, requires
  prompt treatment with ABX to avoid possible
  venous sinus thrombosis, septicemia, meningitis.

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Treatment of Chronic Furunculosis

• (Avoid auto-inoculation, Eliminate carrier
  state.)
• Sites of colonization Nares, axilla, groin and
  perianal.
• Use Anti-staph cleansers soap, chlorhexidine.
• Frequent laundering.
• Bactroban to nares of pt and family members
• BID to nares for one week (q 4th week.).
• Rifampin 600mg QD for 10 days with cloxacillin
  500 mg QID (or Clindamycin 150mg qd for 3 mo)

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Pyogenic Paronychia

• Presentation Tender painful swelling involving
  the skin surrounding the fingernail.
• Etiology Moisture induced separation of
  eponychium from nail plate by trauma or moisture
  leading to secondary infection.
• Often work related
• Bacteria acute abscess formation.
  Candida chronic swelling.
• Treatment
• Avoid maceration / trauma
• ID of abscess
• PCN, 1st Gen Cephalosporin, augmentin.
• Chronic infection requires fungicide and a
  bactericide.

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Pyogenic Paronychia

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Pyogenic Paronychia

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Other predominately Staph Infections.

• Botryomycosis
• Presentation Chronic, indolent d/o characterized
  by nodular, crusted, purulent lesions.
• Sinus tracts discharge sulfur granules. Scaring.
• Uncommon. Assoc with altered immune
  function.
• S. Aureus most common. (Pseudo, E-coli, Proteus,
  Bacteroides, Strep.)
• Pyomyositis
• S. aureus abcess in deep, large striated muscle.
• Most frequent location is thigh
• Occurs in tropics. More frequent in children and
  AIDS pts.
• May not be associated with previous laceration.

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Impetigo Contagiosa

• Presentation 2mm erythematous papule develops
  into vesicles and bullae. Upon rupture a straw
  colored seropurulent discharge dries to form
  yellow, friable crust.
• Etiology S. Aureus gt S. Pyogenes.
• Lesions located on exposed parts of body.
• Group A Strep can cause AGN
• Children lt6 yrs old.
• 2 to 5 of infections
• Serotytpes 49, 55, 57, 60 strain M2 most
  associated
• Good prognosis in children.

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Impetigo Contagiosa

• Treatment
• PCN, 1st Gen. Cephalosporin.
• Topical bacitracin or mupirocin after soaking
  off crust.
• Topical ABX prophylaxis of traumatic injury.
• Reduced infection 47
• Treatment of nares for carriers.

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Impetigo Contagiosa

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Impetigo Contagiosa
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Impetigo Contagiosa
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Bullous Impetigo

• Presentation Large, fragile bullae, suggestive
  of pemphigus. Rupture leaves a circinate, weepy
  crusted lesion (impetigo circinata). Collarette
  of scale present.
• Affects newborns at the 4-10th days of life.
  Adults in warm climates.
• Organism present in the lesions.

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Bullous Impetigo
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Bullous Impetigo
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Staphylococcal Scalded Skin Syndrome.

• Presentation Febrile, rapidly evolving
  generalized desquamation of the skin.
• Primarily affects neonates and children.
  Begins with skin tenderness and erythema of neck
  groin, axillae with sparing of palm and soles
• Blistering occurs just beneath granular layer.
• Positive Nikolskys sign
• Etiology Exotoxin from S. Aureus infection
  located at a mucosal surface (not in lesions).
• Differentiate from TENS
• Treatment as before. Prognosis is good.

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Staphylococcal Scalded Skin Syndrome

Blister plane in granular layer
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Staphylococcal Scalded Skin Syndrome
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Toxic Shock Syndrome

• Presentation
• Acute, febrile, multi-system disease.
• One diagnostic criteria is widespread
  maculopapular eruption.
• Causes
• S. Aureus
• Cervical mucosa historically in early 1980s.
• Also seen with wounds, catheters, nasal packing.
  Mortality 12 .
• Group A Strep
• necrotizing fasciitis. Mortality 30.

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Toxic Shock Syndrome

• Diagnosis CDC
• Temp gt38.9C, erythematous eruption with
  desquamation of palms and soles 1-2 wks after
  onset. Hypotension
• AND involvement of three of more other systems
• GI, muscular, renal, CNS.
• AND Test for RMSF, Leptospirosis and rubeola as
  well as blood urine and CSF should be negative.
• Treatment
• Systemic ABX,
• Fluid therapy
• Drainage of S. Aureus infected site.

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• Streptococcal Skin Infections

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Ecthyma

• Presentation Vesicle/pustule which enlarges
  over several days and becomes thickly crusted.
  When crust is removed a superficial saucer shaped
  ulcer remains with elevated edges.
• Nearly always on shins or dorsal feet.
• Heals in a few weeks with scarring.
• Agent Staph or Strep.
• Heals with scaring
• Gangrene in predisposed individuals.
• Treatment Clean, topical and systemic ABX.

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Ecthyma
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Ecthyma

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Scarlet Fever

• Presentation 24 48 hrs after Strep. Pharyngitis
  onset.
• Cutaneous
• Widespread erythema with 1-2 mm papules. Begins
  on neck and spreads to trunk then extremities.
• Pastias lines accentuation over skin folds
  with petechia.
• Circumoral pallor
• Desquamation of palms and soles at appox two wks.
• May be only evidence of disease.
• Other strawberry tongue
• Causes erythrogenic exotoxin of group A Strep.
• Culture to recover organism or use streptolysin O
  titer if testing is late.
• TX PCN, E-mycin, Cloxacillin.

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Scarlet Fever
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Scarlet Fever
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Scarlet Fever
Rash with circumoral pallor
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Scarlet Fever
Sandpaper Rash
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Erysipelas

• Presentation erythematous patch with a
  distinctive raised, indurated, advancing border.
  Affected skin is very painful and is warm to
  touch. Freq. associated with fever , Headache
  and leukocytosis gt20,000.
• Face and Legs are most common sites.
• Involves superficial dermal lymphatics
• Cause Group A strep., (Group B in newborns)
• Differential
• Contact derm more itching little pain.
• Scarlet fever widespread punctate erythema
• Malar rash of Lupus and Acute tuberculoid
  Leprosy Absence of fever pain and
  leukocytosis.
• Treatment Oral or Systemic abx depending on
  severity.

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Erysipelas
Sharp, raised border.
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Erysipelas

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Erysipelas
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Cellulitis

• Presentation Local erythema and tenderness which
  intensifies and spreads. Often associated with a
  discernable wound. Lymphangitis, fever and
  streaking may accompany the infection.
• Less defined border than erythrasma
• Etiology Group A strep and S. Aureus
• Gangrene and sepsis possible particularly in
  compromised pt.
• Treatment Culture. PCNase resistant PCN, 1st
  Gen Ceph.

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Cellulitis
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Cellulitis
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Cellulitis
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Necrotizing Fasciitis

• Presentation Following surgery or trauma (24 to
  48 hours) - erythema, pain and edema which
  quickly progress to central patches of dusky blue
  discoloration.
• Anesthesia of the involved skin is very
  characteristic.
• By day 4-5 the involved area becomes gangrenous.
• Infection of the fascia.
• Many causative agents. Aerobic and anaerobic
  cultures should be taken.

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Necrotizing Fasciitis

• Treatment Early debridement. ABX.
• 20 mortality in best cases.
• Poor prognostic factors
• Age gt50,
• DM,
• Atherosclerosis,
• Involvement of trunk,
• Delay of surgery gt7 days.

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Necrotizing Fasciitis
Necrosis of the subcutaneous fat and fascia of
the inner aspect of the upper arm in an elderly
patient with diabetes mellitus.
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More Staph and Strep Infections

• Blistering Distal dactylitis
• Superficial blisters on volar fat pads
• Typical pt is 2-16 yrs old
• Perianal Dermatitis
• Superficial, perianal, well demarcated rim of
  erythema which is often confused with irritant
  dermatitis.
• Typical pt is 1-8 yrs old.
• Group B infection
• Consider in any neonates. Also seen in adults
  with DM and peripheral vascular disease.
• Staph Iniae
• 1997 first reported
• Cellulitis of hands assoc with preparation of
  tilapia fish.

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Perianal Dermatitis
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• Other Gram Positive Infections.

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Erysipeloid of Rosenbach.

• Presentation Purple, often polygonal, sharply
  marginated patches occurring on the hands. The
  central portion of the lesion may fade as the
  border advances. New purplish patches appear at
  nearby sites ( or possibly distant sites).
  Painful.
• Causative agent Erysipelothrix Rhusopathiae.
  Rod shaped grm () that forms long branching
  filaments. Culture on media fortified with serum
  at room temp.
• Organism found on dead animal matter and the
  affliction is seen most commonly among fishermen
  (crabs, shrimp), veterinarians, and in the meat
  packing industry (esp pork)
• Treatment PCN 1.0 gm/day 5-10 days.

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Erysipeloid
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Anthrax

• Three forms
• Cutaneous 95 of cases.
• Inhalation
• GI
• Cutaneous presentation Inflammatory papule
  rapidly becomes a bulla surrounded by intense
  erythema which spontaneously ruptures purulent or
  sanguineous contents. A dark brown eschar
  surrounded by vesicles then develops with
  induration. Regional lymph glands then enlarge
  and frequently suppurate. The lesion is not
  tender or painful.
• Mild cases - gangrenous skin sloughs and eschar
  heals.
• In severe cases erythema and extensive edema
  develops. Lesions appear at other sites. Fever,
  prostration and death (20 of untreated cases.)

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Anthrax

• Human infection generally from infected animals.
  Human to human transmission is possible.
• Diagnosis smear with gram stain. Cultures of
  wound.
• Gamma bacteriophage to identify
• Mice serum titer.
• Electrophoretic immunoblots.
• Treatment PCN G 2 million units IV q 6 hours for
  4-6 days followed by oral PCN for 7-10 days.

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Anthrax
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Anthrax
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Anthrax
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Anthrax
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Listeriosis

• Listeria Monocytogenes
• Ubiquitous organism which usually causes
  meningitis of encephalitis.
• Rare cutaneous affliction causing erythematous,
  tender papules and pustules with lymphadenopathy,
  fever and malaise.
• Risk to immunosuppressed
• Neonates Granulomatosis infanta peptica.
• May be missed on bacteriologic exam. Serologic
  test useful.
• Treatment sensitive to most ABX.

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Cutaneous Diphtheria

• Corynebacterium Diphtheriae infection in
  unimmunized individual
• Presentation
• Ulcer with a hard rolled border with a pale blue
  tinge. A leathery gray membrane often coves the
  lesion.
• Eczematous, impetinginous, vesicular or pustular
  scratches.
• Paralysis and cardiac complications from
  diphtheria toxin are possible.
• Common in tropical areas with most U.S. cases
  from non-immunized migrant workers.
• Treatment Diphtheria antitoxin, E-mycin is DOC.
  Also rifampin and PCN.

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Desert Sore

• Ulcerative disease endemic amongst bushmen and
  soldiers in Australia.
• Presentaion Grouped vesicles on extremities
  which rupture to form superficial, indolent
  ulcers that may be 2.0 cm in diameter.
• Cause Staph, Strep and Corynebacterium
  Diphtheria.
• Treatment Diphtheria antitoxin if organism
  present and topical ABX with oral PCN or E-mycin.

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Tropical Ulcer

• Presentation
• Inflammatory papule with vesiculation and ulcer
  formation frequently with undermined edges.
• Pseudomembrane may be present or simply crusting.
  
• Minimal distress other then mild itching.
• Usually single lesion on one extremity.
• Auto inoculation spreads infection.
• Most common in native laborers or school children
  during the rainy season.
• Usually occur at sites of cutaneous injury.
• Etiology Many organisms found under description
  of topical ulcer
• Bacteriodes Fusiformis, spirochetes, anaerobes.

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Tropical Ulcer

• Differential
• Vascular ulcers
• Arteriosclerotic ulcer deep to expose fascia
  and tendons.
• HTN ischemic ulcer shallow, painful mid to
  lower legs.
• Venous ulcers shallow, varicosities. Above
  medial malleolus.
• Other
• Desert ulcer C diptheriae
• Gummatous ulcer punched out, other syphilis
  signs.
• Tuberculous ulcer not usually on leg.
• Mycotic ulcer nodular with fungi on inspection.
• Buruli ulcer Mycobacterium ulcerans.
• Leshmania ulcer contans Leishmania tropicans,
  not on leg.
• Ulcer of blood abnormalities.

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Tropical Ulcer
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Tropical Ulcer
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Erythrasma

• Presentation sharply delineated, dry, brown,
  slightly scaling patches located in intertrignous
  areas. (axillae, genitocrural crease and webs of
  4-5 toes). Rarely, widespread lesions will occur
  with lamellated plaques.
• Lesion are generally asymtomatic except for the
  groin where minor itching may be reported.
• Extensive involvement is assoc. with DM
• Etiology Corynebacterium Minutissimum.
• Diagnosis Woods lamp coral red.
• Treatment e-mycin 250 qid x 7 days. Tolnaftate,
  miconazole, e-mycin, clindamycin topicals also
  effective.

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Erythrasma
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Intertrigo

• Presentation Superficial inflammatory dermatitis
  where two skin surfaces are in apposition.
• Etiology Friction and moisture allows infection
  by bacteria (Staph, Strep, Pseudo.) or fungi or
  both.

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Intertrigo
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Intertrigo
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Intertrigo
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Pitted Keratolysis

• Presentation Thick, weight bearing portions of
  the soles gradually covered by asymptomatic round
  pits 1-3 mm in diameter. Pits may become
  confluent forming furrows. Rarely, palms may be
  affected.
• Etiology unknown. Micrococcus sedentarius in
  synergy with corynebacteria is suspected
• Men with sweaty feet are most susceptible.
• Treatment Topical E-mycin, clindamycin.
  Miconazole, benzoyl perioxide gel, AlCl solution.

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Pitted Keratolysis
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Pitted Keratolysis
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Gas Gangrene

• Presentation Several hours after a patient
  receives a deep laceration, severe pain and wound
  site crepitance develop as well as fever, chills
  and prostration. A mousy odor is characteristic.
• Etiology (2 types)
• Clostridium types perfringens, oedematiens,
  septicum and haemolyticum. Acute onset !
• Peptostreptococcus. Delayed onset up to several
  days.
• Treatment
• Clostridium Wide debridement and PCN G,
  hyperbaric
• Peptostreptococcus Surgical debridement limited
  to glossy necrotic muscle.

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Gas Gangrene
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Chronic Undermining Burrowing Ulcers ( Meleneys
Gangrene)

• Presentation Pt who recently (1-2 wks)
  underwent surgical drainage of a peritoneal or
  lung abscess develops carbunculoid appearance at
  the sutures or wound site. Pain is excruciating.
• The lesion then differentiates into three zones
• outer zone - bright red,
• middle zone - dusky purple,
• inner zone - gangrenous with central areas of
  granulation tissue.

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Chronic Undermining Burrowing Ulcers

• Etiology Peptostreptococcus in periphery. S.
  Aureus or Enterobacteriaceae in zone of gangrene.
• Bacterial synergetic gangrene
• Treatment Wide excision with ABX (PCN and
  aminoglycoside).

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Fourniers Gangrene of the Penis and Scrotum

• Presentation Gangrenous infection of penis,
  scrotum or perineum which spreads along fascial
  planes.
• Etiology Group A Strep or mixed organism.
• Ages 20-50
• Culture for aerobic and anaerobic organisms.
• Treatment ABX as indicated.