Skin and eye infections Flashcards
Characteristics of MRSA?
- skin and soft tissue infections
- caused by Staphylococcus aureus
- G+, cluster growth, nonmotile
- can be highly virulent but considered normal biota
of skin in 1/3 population
- common cause of skin lesions in non-hospitalised people
- strains are resistant to multiple antibiotics
- withstands 7.5-10% salt, extreme pH, and high temps
- remains viable after air drying
-resists the effects of many disinfectants/antibiotics
Signs/symptoms of MRSA?
- raised, red, tender, localized lesions
- features pus and feels hot to touch
- occur easily in breaks in skin and may localize around hair follicle
- fever common
Transmission/epidemiology of MRSA?
- contaminant of all kinds of surfaces
- persons with active MRSA infections should keep them covered to avoid transmission
MRSA culture/diagnosis?
- isolation on blood agar or MSA
- outer and inner zone of hemolysis on plate
- polymerase chain reaction (PCR)
MRSA prevention and treatment?
- prevention via good hygiene
- treatment through incision of lesion and pus drainage
- antimicrobial treatment via more than one antibiotic (vancomycin is recommended in US)
Characteristics/cause of Cellulitis?
Caused by fast-spreading infection in the dermis and in the subcutaneous tissues
- Healthy individuals: staphylococcus aureus or streptococcus pyogenes
- immunocompromised individuals: almost any bacterium and some fungi
- bacteremia could develop, but uncomplicated cellulitis has a good prognosis
Cellulitis signs and symptoms?
- pain, tenderness, swelling, warmth
- fever
- swelling of lymph nodes in area
- lymphangitis: red lines leading away from the area are visible ( the result of microbes and inflammatory products being carried by lymphatic symptoms)
Cellulitis transmission/epidemiology?
Generally follows the introduction of bacteria or fungi into the dermis:
- trauma
- subtle means; no obvious break in skin
Cellulitis culture and diagnosis?
diagnosis through clinical signs and symptoms
Cellulitis prevention and treatment?
- Mild cellulitis responds well to oral antibiotics effective against S. aureus and S. pyogenes
- more involved infections/infections in immunocompromised patients require IV antibiotics
- surgical debridement is required w/ extensive tissue damage
Maculopapular rash disease meaning?
Maculopapular:
- skin eruptions caused by a variety of microbes
- Flat, slightly raised colored bumps
Measles (Rubeola)
Rubella
Fifth Disease
Roseola
Maculopapular rash disease meaning?
Maculopapular:
- skin eruptions caused by a variety of microbes
- Flat/slightly raised colored bumps
Measles (Rubeola)
Rubella
Fifth Disease
Roseola
Measles/Rubeola signs and symptoms?
- sore throat
- dry cough
- headache
- conjunctivitis
- fever
- oral lesions called Koplik’s spots
- red maculopapular rash that erupts on the head and progresses to the trunk and extremities
Measles comorbidities/ complications?
- laryngitis
- Pneumonia
- secondary bacterial infections
- subacute sclerosing panencephalitis (progressive neurological degeneration) resulting in CNS changes
Measles transmission?
- transmitted by respiratory droplets
- Humans are the only reservoir
- Person is infectious during the periods of incubation, prodrome phase, and the skin rash but not during convalescence
Measles Culture and diagnosis?
- clinical presentation
- ELISA to test for IgM to measles antigen
Measles prevention/ treatment?
- MMr vaccine contains a live attenuated virus (20 years protection)
- Recommended for healthy children 12-15 months + booster b4 school - supportive treatment to treat symptoms
Vesicular or Pustular rash disease catagories
- chickenpox: common & mostly benign
- Smallpox: eradicated but very serious
- both viral and present generalized rashes - Pox: individual lesions that contain fluid
Chickenpox signs and symptoms?
- fever and abundant rash appear after 10-20 day incubation period
- rash begins on scalp, face, trunk, and radiates to the extremities (centripetal distribution)
- itchy vesicles encrust and drop off after several days; heal completely or may leave a small scar (4-7 days)
- patients are usually considered contagious until all lesions have crusted over
- ~0.1% pf cases followed by encephalopathy which can be fatal
Shingles characteristics?
virus enters the sensory endings of cutaneous spinal nerve branches after recovery from chickenpox
- becomes latent in the ganglia and may reemerge as shingles abruptly after reactivation by psychological stress, immunosuppressive and other drug therapy, surgery, or developing malignancy
Shingles signs and symptoms?
- asymmetrical distribution on the skin of trunk or head
- produces crops of tender persistent vesicles
- Postherpetic neuralgia: inflammation of the ganglia and nerve pathways that cause pain and tenderness and can last several months
- involves spinal nerves
- cranial nerve involvement can lead to eye inflammation and ocular/facial paralysis
Chickenpox/shingles causative agent?
human herpesvirus 3 (HHV-3) AKA varicella
- enveloped DNA virus
Chickenpox/ shingles transmission/epidemiology?
- human = only natural host
- harbored in respiratory tract
- communicable from both respiratory droplets and
fluid from active lesions
-infected persons are infectious 1-2 days prior to development of rash
-highly contagious
Chickenpox/shingles prevention?
- live attenuated vaccine (1995)
- zostavax approved by the FDA (2006) to prevent shingles
