Bacterial and Viral Skin Infection Flashcards
Impetigo:
- cause
- transmission
- PE findings
- Tx
Cause: streptococci, staphylococci
Transmission: touch, contagious superficial skin infection.
PE:
- nonbullous or bullous
- vesicles and bullae containing clear yellow or slightly turbid fluid without surrounding erythema.
- golden yellow (honey) crusted
- Post streptococcal (GABS) glomerulonephritis may follow
Tx:
- bactroban (Mupirocin) ointment
- Severe cases: oral abx; cover for staph aureus Bactrim, clindamycin, or doxy
Meningococcemia
- cause
- MC age
- prognosis
- PE findings
- dx
- tx
Cause: neisseria meningitidis
MC age is 6mo-3yrs
Prognosis: rapidly lethal form of septic shock d/t waterhouse-friderichsen syndrome.
PE findings:
-high fever, tachycardia, mild hypotension, meningeal irritation (knees drawn up, cant move head much, and appears acutely ill)
- exanthem: pink 2mm-10mm macules/papules, sparsely distributed on trunk/lower extremities, face, palate, and conjunctivae.
- late lesions: petechiae in center of macules, lesions become hemorrhagic within hours, purpura fulminans(rapidly expanding purpura), hemorrhagic bullae
Dx:
- blood cultures
- pus from nodular lesion shows gram neg diplococci
- D-dimer +
Tx:
- Cefotaxine (Claforin)
- Ceftriaxone (Rocephin)
- Hemodynamic stabalization
What is Waterhous- Friderichsen syndrome?
is defined as adrenal gland failure due to bleeding into the adrenal glands. It is characterized by overwhelming bacterial infection meningococcemia leading to massive blood invasion, organ failure, coma, low blood pressure and shock, disseminated intravascular coagulation (DIC) with widespread purpura, rapidly developing adrenocortical insufficiency and death.
Bacterial Endocarditis:
- cause
- MC in who?
- sx
- PE
- skin lesions
- dx
- tx
Cause: staph aureus, strep viridans
MC in IVDU, elderly, prosthetic valves
Sx: fever, chills/sweats, anorexxia, wt loss, malaise
PE: heart murmur, arterial emboli, splenomegaly
Skin lesions:
- Janeway Lesions: non-tender hemorrhagic maculopapular lesions on palms and soles
- Oslers nodes: painful, red nodules on fingertips
- Subungual splinter hemorrhage
- Petechial lesions; small non-blanching, reddish brown macules on extremities, upper chest, mucous membranes, occurs in crops, may be asymptomatic red streaks in nail bed.
dx: blood cultures, CBC, chem panel, coags, echo
Tx:
- PCN G
- Nafcillin
- Gentamycin
- Vanco or Zyvox in MRSA
Rocky Mountain Spotted Fever:
- cause
- vector
- sx
- skin lesions
- Tx
Cause: rickettsie rickettsii spirochete
Vector: tick bite
Sx:
- prodrome: anorexia, irritability, malaise
- fever (102), chills, weakness
- HA, photophobia
Skin lesions:
- 2-6mm pink blanching macules begin on extremities and spread centrally, later on palms
- evolve to papules & petechiae over hours to couple of days
Tx:
- Doxycycline or chlorampheical (except if pregnant)
- *start abx if dz is even suspected.
- *Doxy even in children now per the CDC.
Lyme Dz ;
- cause
- describe the rash
- sx
Cause: bacterial infection by spirochete Borrelia burgdorgeri (tick bite)
Rash:
- appears several days after infection, or not at all
- can last few hours or up to several weeks
- can be very small or large (up to 12 inches across)
- can itch or feel hot
- can disappear and return after several wks later.
- bullseye rash
Sx:
- HA
- stiff neck
- myalgias and arthralgias
- low grade fever
- fatigue
- sore throat
- after several months arthritis-like sx may develop including painful and swollen joints.
Lymes:
- dx
- tx
Dx:
- clinical, may mimic other conditions
- Hx of tick bite is useful.
Tx:
- doxycycline for adults and children older than 8YO
- amoxicillin for adults, children, pregnant or breast feeding.
Cellulitis:
- cause
- what is this?
- PE
- dx
- tx
Cause: Staph aureus and Group A strep, trauma/tissue compromise.
What: infection of dermal and subQ tissue
PE:
- warmth, erythema, edema, and tenderness
- flat, non-palpable margins
- violaceous color and bullae suggest strep pneumo infection
Dx:
- clinical
- no workup is required if small area of involvement, minimal pain, no systemic signs of illness
- if complicated: CBC, blood cultures, chem panel
Tx:
- mild: bactrim, clinda, doxy*—cover MRSA
- complicated: IV abx
- -Ancef (Cefazoline)
- -Ceftriaxone
- -ampicillin-sublactam
Erysipelas:
- cause
- describe rash
- sx
- Tx
Cause: Group A hemolytic strep
Rash:
- begins small erythematous patch that progresses to a fiery red* indurated, tense, and shiney plaque. (St Anthonys Fire)
- raised and sharply demarcated advancing margins
- spread via lymphatics
Sx:
- warmth, edema, tenderness
- prodrome: malaise, chills fever
- painful
- rash gradually increases in size.
Tx:
- PCN G or PCN VK
- Dicloxacillin
- Keflex
- Clinda
- Erythro
Human Bites
- MC bacteria
- MC in who
- dx
- tx
MC anerobes
MC in young males
Dx:
- clinical
- XRAY to r/o osteomyelitis, metacarpal head fx
Tx:
- Augmentin
- Moxifloxin
- Clinda
- TETANUS SHOT!!!
Dog and Cat Bites
- MC bacteria from cat bites?
- tx
MC bacteria is Pasturella
Tx:
- inspect, debride, irrigate
- -primary closure for wounds that can be cleaned effectively
- -facial wounds can be closed
- -lower extremity wounds need delayed closure
- TETANUS SHOT
- Abx:
- -augmentin
- -erythromycin
- -bactrim
- -clinda
- -cipro
Necrotizing Fasciitis:
- bacterial cause
- what is this?
- how does the bacteria get inside you?
- sx
Cause: group A hemolytic streptococci, staph
What: progressive, rapidly spreading, inflammatory infection of deep fascia w/ 2ndry necrosis of subQ tissue.
How: trauma, recent surgery, insect bites, IM injections, IV infusions, idiopathic
sx:
- suddden onset of pain, swelling, and redness at site of trauma or recent surgery that quickly spreads
- local pain progresses to anesthesia
- margins of infection move out into normal skin without being raised or sharply demarcated
- progresses to dusky or purplish skin discoloration near site of insult. (beginning of gangrene)
Necrotizing fasciitis
- signs and sx
- work up
- tx
Signs and sx:
- tissue necrosis
- putrid discharge
- bullae
- severe pain
- gas production
- rapid burrowing through fascial planes
- lack of classical inflamm signs
Work up:
- CBC w/ diff
- chem panel
- blood and tissue cultures
- UA
- ABGs
- Xray
- CT
- bx to dx*
Tx: agressive ABX, hemodynamic stabilization, surgical consult for debridement, hyperbaric after debridement
- ceftriaxone
- PCN-G
- Clinda
- Flagyl (anerobes)
- gentamycin
- chloramphenical
Hidradenitis Suppurativa
- what is this?
- onset
- sx
- tx
What: chronic suppurative dz of apocrine gland-bearing skin, especially in the groin and axilla.
Onset: puberty
Sx:
- intermittent pain and marked point tenderness related to abscess formation
- red inflamm nodules
- drain purulent/seropurulent materal
- open comedones
- lesion may become infected
Tx:
- combo of:
- -intralesional glucocorticoids: Triamsinolone
- -PO steroid: prednisone
- -Surgery: I&D as last resort
- -PO Abx: erythro, tetracycline, minocycline
- -Isotretinoin (Acutane)
grouped vesicles on an erythematous base and very contagious..what is this?
HERPES SIMPLEX VIRUS!!!!
