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33 Cards in this Set
- Front
- Back
Natural Defenses of the skin: KSSSL |
Keratin Skin Sloughing Sebum Sweat Lysozyme |
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Keratin: |
Tough waterproof layer |
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Skin sloughing: |
every 20-40 days |
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Sebum: |
Low pH, high lipid |
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Sweat: |
Low pH, high salt |
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Lysozyme: |
which digests peptidoglycan |
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Normal skin flora: |
-Propionibacterium acnes -Corynebacterium spp. (Diphtheroids) -Micrococcus spp. -Staphylococcus app. ---Staphylococcus epidermidi --Staphylococcus aureus -Streptococcus spp -Yeasts -Many others |
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Acne causative agent: Propionibacterium acnes |
Propionibacterium acnes -Gram + rod -digests sebum -attracts neutrophils -Neutrophil digestive enzymes cause lesions, "puss pockets" (pimples) -Most common skin disease in humans -Oil-based cosmetics worsen disease |
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Acne Treatments: |
Benzoyl peroxide dries plugged follicles, kills microbes -Tetracycline (antibiotic) -Accutane- inhibits sebum formation |
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Impetigo |
-Caused by --Staphylococcus aureus --Streptococcus pyogenes * Peeling crusty skin ** Contagious!!!! |
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SSSS: Staphylococcal scalded skin syndrome |
-Caused by: Staphylococcus aureus -Large red blisters that peeled off in sheets -Typically not deadly although very painful |
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Staphylococcus aureus |
is associated with a number of diseases, including impetigo and SSSS -Enzymes are virulence factors -Coagulase (diagnostic test for S.aureus) -Hyaluronidase -Staphylokinase -Lipases ** Most treated pathogen*** |
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Scanning Electron Micrograph (SEM) and colonies of Staphylococcus aureus: |
The causative agent of impetigo |
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Necrotizing Fasciitis "Flesh Eating Strep" GROUP A STREP- |
Streptococcus pyogenes***** -Tissue digesting enzymes: ~Hyaluronidase ~Streptokinase ~Streptolysins *Rapidly spreading cellulitis may lead to loss of limb |
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Necrotizing Fasciitis: |
Disease starts as localized infection. Pain in area, flu-like symptoms. -invasive and spreading -may lead to toxic shock (drop in blood pressure) -incidence 1-20/100,000 -30-70% mortality -surgical removal |
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Rocky Mountain Spotted Fever |
* Fever, skills, headache, muscle pain - Red ---> black rash ~ blackish caused by hemorrhaging ----Petechiae ** Transmitted to humans BY TICK BITES (Vector- biological transmission) Now found mostly in Eastern Atlantic states |
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Rocky mountain spotted fever treatable with... |
antibiotics -diagnosed using fluorescent antibodies on tissue samples, PCR -30% of untreated cases and 5% of treated cases are still fatal |
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Rickettsia rickettsii |
--Gram negative bacillus or coccobacillus ---Obligate intracellular parasite |
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Rickettsia an Obligate Intracellular Parasite: |
-bind to cell surface and are taken into ENDOTHELIAL CELLS -Escape from phagosome into cytoplasm -Have ETC -Obtain nutrients, NAD+ and CoA from host -Cause capillaries to degrade |
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Rickettsia rickettsii vectors: |
Wood Tick and Dog Tick |
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Virus infections of the Skin: Vesicles |
Vesicular or pustular rash (elevated lesions filled with fluid) |
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Cold Sores |
Human simplex 1 and 2 |
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Chickenpox |
human Herpesvirus-3 |
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Smallpox |
-A disease with an interesting history -Very infectious VIRAL disease (epidemic) -The disease has been eliminated due to world-wide vaccine program: --Vaccinia: a Jennerian vaccine named for Edward Jenner, 1796 **Virus has been preserved in government labs by agreement, at CDC in Atlanta and in Russia. Considered a bioterrorism agent*** |
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Smallpox Death rate and history stats: |
-Known for 1000s of years -Overall death rate was 20-80% of those infected --death in children was more common -18th century- 400,000 per year die (Europe) -20th Century -3 to 5 million deaths per year -Global vaccine eradicated the disease globally ---fully eradicated by 1980 |
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Chickenpox "Varicella-Zoster" |
-Common virus; decreasing disease in the USA due to effective childhood vaccine -Benign disease with life long immunity -Life-threatening for immunocompromised individuals -Recuperation can result in life long benign Varicella-zoster virus latency -May re-emerge as shingles (skin lesion) |
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Chickenpox virus in the body: Viral infection through AEROSOL DROPLET; systemic infection---> |
local infection in LYMPH NODE(S) (neck) --lymphocyte associated viremia -----fever, malaise ~spread throughout the body ~shed in respiratory tract secretions and Skin Vesicles (blisters of clear fluid) --Recovery with virus latency in neurons --> life long immunity |
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Chickenpox reemerges as SHINGLES CAUSES: |
Stress, immune suppression, drug therapy? |
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Virus Infections of the Skin: Rashes Spots, Bumps Maculo-papular rashes (flat to slightly raised colored bump) |
Measles virus (Rubeola) Rubella Virus (German Measles) Fifth Disease (Human Parvovirus B19) |
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Measles |
VIRAL infection through AEROSOL DROPLET: one of the MOST communicable viruses |
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Measles: Initial infection of the oro-pharynx |
--> local infection lymph node (s) of the -->lymphocyte associated viremia fever, malaise --> spread throughout the body --> Shed in respiratory tract secretions Koplik's spots Skin rash --> recovery; life long immunity *** Effective childhood vaccine (2-3 doses): MMR (measles, mumps, rubella ), but disease still exists worldwide |
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Measles World Wide |
** Measels is the leading cause of vaccine-preventable death among children ** Millions of children still remain at risk from measles - Developed countries measles death rates range from 1-5%, but among malnourished children, the death rate reaches 10-30% - over 500,000 children under the age of five die/yr -measles causes health complications, including pneumonia, diarrhea, encephalitis ---THE PRIMARY reason for ongoing high childhood death is the failure to deliver at least one dose of measles vaccine. |
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Rubella: Viral infection through AEROSOL DROPLET; systemic infection--> |
A mild rash -serious for a fetus when contracted in the first trimester of pregnancy -disrupts fetus development of the CNS and/or other organs: Congenital Rubella Syndrome ---small birth weight, blindness, hearing loss, mental retardation, heart problems ---infection lasts for months-years in the newborn ** Vaccine highly effective (MMR)** |