7. Diseases of the skin, soft tissue and wounds

  1. natural defenses of the skin and eye
    • outer thick layer of keratinized dead cells
    • sebaceous glands
    • endogenous organisms
    • lysozyme
  2. cause of ringworm
    dermatophytes - species of fungi
  3. ringworm reservoir and transmission
    reservoir - humans, animals, soil

    transmission - direct contact with reservoir or fomites
  4. ringworm pathogenesis
    • grow only in the dead, keratinized outer layer
    • cannot grow internally
    • grow best in moist areas
  5. ringworm diagnosis
    wood's light - fungi flouresce at UV wavelength of the light

    skin scrapings are looked at under the microscope - morphology
  6. ringworm host defense
    very poor - inhabit outer layer where there is no blood supply
  7. ringworm treatment
    • topical ointment
    • systemic treatment - griseofulvin
  8. ringworm prevention
    • elimination of excess skin moisture
    • powders
    • anti-fungal ointments
  9. cause of pyodermas
    staphylococcus aureus
  10. pydomeras reservoir and transmission
    reservoir - humans

    transmission - direct contact or fomites
  11. pyodermas pathogenesis
    • main carriage is in the nose
    • causes noscomial infections
    • penicillin-resistant strains
  12. pyodermas clinical manifestations
    • boil or pimple
    • impetigo - lesions
    • sty
    • abcesses, cellulitis
  13. pyodermas diagnosis
    • laboratory - morphology, gram staining reaction, ability to produce coagulase
    • antibiotic sensitivity testing
  14. pyodermas host defense
    immune response is not good - infections too superficial to get into blood and stimulate response
  15. pyodermas treatment
    • drainage of large lesions
    • antibiotic taken orally or intravenously
    • antibacterial ointment
  16. pyodermas prevention
    • good hygiene
    • elimination of carriers among hospital personnel by treating with antibiotic ointment
    • - disinfection of hospital surfaces
    • there is no vaccine
  17. cold sore cause
    herpes simplex virus type I
  18. cold sore reservoir and transmission
    • humans
    • direct contact - usually kissing
  19. cold sore host defense
    no protective immune response
  20. cold sore treatment
    • generally not treated - resolve on their own
    • acyclovir may be used
  21. cold sore prevention
    • usually secondary - avoid triggering factors
    • avoid kissing people with cold sores - only transmissible from the sore
  22. bacteria and the wound infections they cause
    • clostridium perfringes - gas gangrene
    • bacteroides species - perirectal abcesses
    • streptococcus pyogenes - flesh-eating bacteria
    • staphylococcus aureus and peptostreptococcus species - necrotizing fasciitis
    • pseudomonas aeruginosa - burn infections and severe eye infections
  23. wound infections pathogenesis
    • invasiveness
    • infect tissue that has become anaerobic through loss of blood supply from injury, surgical wounds, or diseases that result in poor circulation
    • multiply and produce enzymes that destroy the tissue and becomes anaerobic - spreads rapidly
  24. wound infections diagnosis
    signs, culture and identification of organisms isolated
  25. wound infections treatment
    • antibiotics of peripheral area
    • amputation or excision of infected tissue
    • oxygenation of tissue with hydrogen peroxide
  26. Leprosy or Hansen's Disease cause
    mycobacterium leprae
  27. Hansen's disease reservoir and transmission
    • humans
    • not known for certain - incubation period is long
  28. clinical forms of Hansen's disease
    tuberculoid form - less severe, scaling/ discoloration of the skin, more common

    lepromatous form - more severe, disfigurement, less common

    depends on immune response
  29. Hansen's disease pathogenesis
    • obligate intracellular parasite - destroys cells it multiplies in
    • destroys nerves - leads to lack of feeling
  30. Hansen's disease diagnosis
    • appearance of lesions and lack of feeling in lesions
    • laboratory diagnosis
  31. Hansen's disease host defense
    CMI because intracellular
  32. Hansen's disease treatment
    multidrug therapy with dapsone
  33. Hansen's disease prevention
    • dapsone treatment of exposed genetically susceptible persons
    • treatment of patients helps prevent spread to others
Card Set
7. Diseases of the skin, soft tissue and wounds
public health microbiology midterm 2 lecture 7