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Bacterial DiseasesFungal Infections


Bacterial Diseases (continued)

 

 

 

 

 

 

Neisseria meningitidis
Neisseria meningitidis

    Meningococcal Infection Types A, B, C 
    Severe disease:

     

    Transmitted by droplets via upper respiratory tract

    Mainly children < 10 yrs. old

    Acute meningococcal septicemia & meningitis

    Rash:

     

    40-90% of cases

    Pink macules - purpura nearly any site
    Purpuric eruption - trunk, limbs

    Severe cases: Extensive ecchymoses or necrotic ulcers; associated with high mortality
    Diagnosis: Blood/CSF culture

     

 

 

Erythrasma
Erythrasma

Erythrasma
Erythrasma

 

Coryneform bacteria

Corynebacterium minutissimum: Causative agent of erythrasma
Erythrasma: Sharply marginated erythematous patches with fine scale of axillae and groin
Diagnosis: Wood's light exam (reveals coral red fluorescence)

 

 

Pseudomonas
Pseudomonas

Pseudomonas
Pseudomonas

Pseudomonas
Pseudomonas

 

Pseudomonas

Pigment formation: Blue-green pyocyanin; greenish-yellow fluorescein

Colonizes burns, ulcers, moist skin lesions, and nails

Infancy: Periumbilical
Burns: Leading to secondary septicemia
Hot tub folliculitis: Worse in areas covered by bathing suit

Settles spontaneously 7-10 days

Hot tubs/whirlpool; chlorination no help

"Tropical immersion foot": Toe webs, maceration

Sharply demarcated maceration tinged with green

Pseudomonas septicemia: Severely compromised host

Bullae (moist areas: axillae/perineum/buttocks) -> necrotic ulcers: ecthyma gangrenosum

Prognosis grave even with early treatment


  

 

Lyme Disease
Lyme Disease

 

 

 

 

 

 

 

 

 

 

 

 

 

    Spirochetes

    Borrelia burgdorferi

    Tick bites: Ixodes dammini/pacificus
    Lyme Disease:

     

    Skin disease plus a disease of nervous system, heart and joints
    Erythema chronicum migrans (ECM):

     

    1-36 days after bite.  Untreated lesion fades within a few weeks.  

    Dissemination of infection is from days to weeks after inoculation. 

    Arthritis/neural (meningitis, cranial nerve palsies), myocarditis, conduction defects.

    Other cutaneous manifestations: 2 lesions of ECM in 10% of patients.  Lesions are smaller and less migratory.

    Lymphocytoma

    Acrodermatitis chronica atrophicans

    ?Morphea/LSA

    Diagnosis: Serology, tissue culture
  
 

Syphilis
Syphilis

Syphilis
Syphilis

Syphilis
Syphilis

Syphilis
Syphilis

Syphilis
Syphilis

 

Treponema pallidum

Increasing incidence
Incubation: 9-90 days
Cutaneous manifestations:
1 lesion: "Chancre" - painless ulcer with indurated edge
2 lesions: Macules, papules of trunk, palms, and soles; condylomata; hair loss
3 lesions: Gumma (full thickness tissue destruction)
Congenital syphilis: "Snuffles"

Stigmata of congenital syphilis (Hutchinson's teeth, sabre shins)

Rapid course in HIV+ patients: May have negative serology & may not respond to conventional treatment
In HIV: Primary chancre may be painful secondary to Staph. super-infection
Diagnosis: Dark field examination, serology (VDRL, RPR, FTA-ABS, ELISA)

 

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