Week 12 Flashcards
Staphylococcus Aureus - causes 4 diseases
1) Localized abscess (skin/bone)
2) Sepsis + acute endocarditis
3) hospital-aquirred and post-influenzal pneumonia
4) toxin-associated syndromes
Abscess to bone
Osteomyelitis
Staphylococcus Aureus - shape
cocci
Staphylococcus Aureus - gram status
gram positive
Staphylococcus Aureus - virulence factors (3)
- cell wall
- protein A (inhibits phagocytosis)
- membrane damaging exotoxins
Folliculitis - what
when hair follicles become inflammed
Folliculitis - cause
bacterial or fungal infection
Folliculitis - symptoms
- small red bumps or white headed pimbles around hair follicles
- can spread and turn into nonhealing crusty sores
- tenderness/itchiness at site
Folliculitis - complications
- Furnicle (abscess/deep pustule)
- Carbuncle (a group of follicles that coalece into one painful infected area)
Folliculitis - common names (3)
- hot tub rash
- razor bumps
- barber’s itch
Staphyloccocal Scaled Skin Syndrome - what
- diffuse, scarlet fever-like rash
- deeper skin infection
Staphyloccocal Scaled Skin Syndrome - pathogenesis
superficial layers of epidermis are separated and shed in sheds
- caused by hematologic spread of toxins from focal infection (nasopharynx, superficial skin abrasion)
Staphyloccocal Scaled Skin Syndrome - at risk population
children under 5
Staphyloccocal Scaled Skin Syndrome - symptoms (5)
- scarlet fever-like rash
- malaise
- fever
- irritability
- extreme tenderness over the skin
Bullous Impetigo - pathogenesis
- a thin blister that erupts and appears to be cloudy
- eventually rupture and crust
- caused by staphylococcus
Where are Bullous Impetigo found (4)
- trunk
- axilla
- extremities
- diaper area
Methicillin Resistant Staph Aureus - what
a bacteria resistant to several antibiotics
Methicillin Resistant Staph Aureus - complications
- pneumonia
- surgical site infections
- sepsis
- death
Methicillin Resistant Staph Aureus - risk
areas like hospital and nursing home - causes outbreaks
Methicillin Resistant Staph Aureus - transmission
- direct contact with an infected wound
- contaminated hands (of HCP)
- contact with MRSA carriers
Methicillin Resistant Staph Aureus - diagnosis
culture of bacteria
Group A beta-hemolytic streptococci - infects what
- skin and soft tissue infections
Group A beta-hemolytic streptococci - types of skin infections
1) impetigo
2) celulitis
3) erysipelas
4) necrotizing faciitis, non gas forming
impetigo
reddish sores on the face, especially around the nose and mouth and on the hands and feet.
Celulitis
a common bacterial skin infection that causes redness, swelling, and pain in the infected area of the skin
erysipelas
a skin infection involving the dermis layer of the skin, but it may also extend to the superficial cutaneous lymphatics. It is characterized by an area of erythema that is well demarcated, raised, and often affects the lower extremities, with the face being the second most commonly affected site.
Necrotizing facitis
- flesh eating disease
Group A beta-hemolytic streptococci - gram status
gram positive
Group A beta-hemolytic streptococci - oxygen status
aerotolerant (no oxygen)
Group A beta-hemolytic streptococci - virulence factors (3)
- capsule containing hyaluronic acid
- fimbriae
- exotoxins
impetigo - common group
infants and young children
impetigo - common season
warm summer months, warm moist climates
impetigo - contributing factors (2)
- overcrowded housing
- poor hygeine
impetigo - presentation
small vesicle or pustule or bulla on the face (can occur elsewhere)
impetigo - pathogenesis (3)
- small vesicle or pustule or bulla on the face (can occur elsewhere)
- primary lesion ruptures and leaves area that discharges honoey coloured liquid that hardens and crusts
- new vessicles erupt in hours, and pruitis causes scratching to multiply infection sites
Erysipelas - what
- infection of upper layers of the skin
- group a streptococcus
- fiery red rask with raised edges
- warm to touch
Erysipelas - pathogenesis
- minor traua (bruise, burn, wound, incision)
- rash then appears on trunk, arm, legs at localized lesion
Erysipelas - symptoms
- firery rash
- high fever
- chills
- headache
- nausea
- malaise
Cellulitis - what
- deper infection affecting dermis and subcutaneous tissues
Cellulitis - common sites
legs
hands
pinnae of ears
Cellulitis - rash
lesion consisting of expanding red, swollen, tender plaque with indefinite border, covering a small to wide area
Cellulitis - accompaning symptoms
- lesion
- fever
- erythema
- heat
- edema
- papin
Cellulitis - complications
- septicemia
- nephritis
- death
Measles: which virus
morbillivirus
Scarlet fever: which bacteria
streptococcus pyogenes
Rubella: which virus
togavirus
Erethema infectiosum: which virus
Panovirus B19
Roseola infantum - which virus
HHV-6 HHV-7
Measles (Rubeola) - genetic material
RNA
Measles (Rubeola) - rash
- macular and blotchy
- begins on face and spreads to apendages
Measles (Rubeola) - transmission
- direct contact with discharge from nose and throat
- air-borne droplets from infected person
Measles (Rubeola) - symptoms
- rash
- fever
- Cough
- Coryza
- Conjuncivitis
- Koplik spots in mouth
Coryza
inflammation of mucus membrane in the nose
Koplik spots
- tiny, bluish white spots on erethematous base
- cluster adjacent to molars on buccal mucosa
Measles (Rubeola) - prevention
proper immunization with vaccine
Rubella - rash characteristics
- diffuse, pinkish macular rash
- begins on trunk and spreads to arms and legs
Rubella - symptoms (4)
- mild fever
- rash
- postauricular, suboccipital and cervical lymphadenopathy is common
- cold-like symptoms
Rubella - transmission (2)
- pregnant mother to unborn child
- contact with secretions from another infected person
Rubella - prevention
proper immunization with vaccine
Rubella - long-lasting consequences
- none for adults and children
Rubella - pregnant woman early in gestation - complication
- congenital rubella syndrome
- miscarriage
congenital rubella syndrome - symptoms (12)
- cataracts
- microcephaly
- mental retardation
- deafness
- Cardiac defects
- patent ductus arteriosus
- tetralogy of fallot (VSD with RV outflow obstruction)
- pulmonic stenosis
- glaucoma
- bone defects
- tetralogy of fallot (VSD with RV outflow obstruction)
- pulmonic stenosis
- overriding aorta
Roseola Infantum - virus
Human Herpesvirus Type 6 (HHV-6)
Roseola Infantum - age
- 95% below age 3
- peak age = 9 months
Roseola Infantum - why the target age?
- transplacental antibodies protect infants until 6 months of age
- develop own immune system after age 3
Roseola Infantum - type of rash
- maculopapular rash
- cover trunk, spread to appendges
Roseola Infantum - symptoms
- rash
- abrupt onset of high fever (40)
- irritability
Roseola Infantum - complication
febrile seizures
Erythema Infectiosum - which virus
Human Parovirus B19
Erythema Infectiosum - transmission
- direct contact with nasal/throat discharge
- also through blood
- vertical transmission (mother and fetus)
Erythema Infectiosum - symptoms (3)
- rash
- pruitis (itchy)
- rarely has a high fever
Erythema Infectiosum - pathogenesis
- bright erethematous rash at first on cheeks and forhead, circumoral pallor
- may reappear as child is exposed to sunlight, extremes in temp, or trauma for the skin
- symetric “lacey” maculopapular rash on trunk happens next
Erythema Infectiosum - pregnancy complication
- fetal hydrops
- death of fetus
fetal hydrops
large amounts of fluid build up in a baby’s tissues and organs, causing extensive swelling (edema
Chicken pox - virus
varicella-zoster virus (form of herpes virus)
Varicella - stagers of skin
1) Papular stage
2) vesicle stage
3) ulcer/scabbing stage
Varicella - Papular stage (2)
- stage 1
- development of papules over the trunk, spreading to limbs, buccal mucosa, scalp, axillae, URT, conjunctiva
Varicella - Vesicle stage (2)
- stage 2
- Papules formed in stage 1 turn into vesicles (fluid)
Varicella - ulcer stage (2)
- stage 3
- vesicles from stage 2 break open and scab over
Varicella - symptoms
- various stages of lesions
- mild to extreme pruitis (leading to scratching and complicated bacterial infections)
- mild fever
Varicella - transmission
- direct contact
- airborne droplet particles
Varicella - complications (7)
- secondary bacterial infections
- pneumonia
- encephalitis (brain inflammation)
- cerebellar ataxia (decreased muscle coordination)
- transverse myelitis (inflammation of spinal cord)
- Reye syndrome (serious multi-system condition)
- Death
Varicella - susceptible populations (5)
- infants
- adults
- pregnant women
- unborn babies if mother had not had chicken pox
- immunocompromised people
Herpes Zoster - common name
shingles
Shingles: virus
varicella-zoster
Shingles - pathogenesis
- result of reactivation of latent varicella-zoster virus infection
- infection that has been dormant in sensory dorsal root ganglia since primary infection
Shingles - contagious? (2)
- YES. contagious.
- passes on Chickenpox NOT shingles to non-immune individual
At-risk population for shingles (4)
- people aged 50+ (due to impaired t-cell mediated immunity)
- Immunocompomized (HIV infected, chemo)
- certain malignancies
- chronic corticosteroid users
Progression of Shingles (2)
1) prodrome (burning, tingling, neuropathic pain, extreme sensitivity of the skin to touch, pruitis)
2) lesions appear as eruption of vesicles with erethamous base
Shingles complications
- Eye involvement (blindness,)
- postherepetic neuraligia (pain 1-3 months after rash)
Shingles prevention
- live attenuated vaccine for herpes zoster for people 50+
Hand Foot and Mouth disease - what (2)
- ulcers inside a child’s mouth,
- AND a rash/blister on hands, feet, legs, buttocks
Hand Foot and Mouth disease - which virus
coxsackievirus A5
Hand Foot and Mouth disease - severity
painful, but isnt serious
Hand Foot and Mouth disease - common age
children under 5
Hand Foot and Mouth disease - transmission (4)
- droplets
- contact with infectious material
- fecal-oral transmission
Fungal skin infections - classifications (2)
deep or superficial
Superficial fungal infections - pathogenesis
- invade only superficial keratinized tissue of skin, hair, nails
- emit an enzyme that can digest keratin
Superficial fungal infections - examples
- tinea/ringworm
Superficial fungal infections - symptoms (3)
- superficial sk in scalding
- nail disintegration
- hair breakage
d/t breakdown of keratin
Deep fungal infections - pathogenesis
- invade epidermis, dermis, and subcutaneous tissue
Diagnosis of superficial fungal infections (4)
- skin scrapings
- potassium hydroxide (KOH) disintegrates human tissue
- KOH leaves behind hyphae
- examine under microscope
Dermatophyte infections - what
- superficial fungal infection
- confined to keratin layer of epidermis
Dermatophyte infections - 3 genera
- microsporum
- epidermophyton
- tychophyton
Dermatophyte infections - types (7)
- tinea coporus = ringworm, body
- tinea faciale = face
- tiniea capitis = scalp
- tinea manus = hands
- tinea pedis = feet
- tinea unquium = nails
- tinea cruris = genitalia
Candida Albicans - what
fungal infection - yeast
Candida Albicans - pathogenesis
Candida Albicans refleases irritating toxins on skin surface
Candida Albicans - risk populations (5)
- antibiotic therapy
- pregnancy
- oral contraceptive use
- poor nutrition
- immunosuppressive diseases
Candida Albicans - location on body
- warm, moist areas of the body
Candida Albicans - rash characteristics (2)
red with well-defined border
Candida Albicans - symptoms (3)
- red rash
- mild to severe itching/burning
- satellite lesions (macopapular and found outside border of infection)
