Bacterial and Viral infections Flashcards
Characteristics of impetigo? What may follow impetigo?
- common, contagious, superficial skin infection
- caused by streptococci, staphylococci, or combo
- high incidence in kids
- self limiting, but if not tx may last for weeks or months
- post strep glomerulonephritis may follow impetigo
What will you see on PE of impetigo?
- nonbullous and or bullous
- vesicles and bullae containing clear yellow or slightly turbid fluid w/o surrounding erythema:
superficial small vesicle or pustules, 1-3 cm lesions, and honey crusted
Tx of impetigo?
- bactroban (mupirocin) ointment
- systemic abx - not worried about MRSA - keflex
- in severe cases: oral abx (cover for staph aureus - to cover MRSA: bactrim, clindamycin or Doxy)
Characteristics of meningococcemia - Bug?
What ages?
- Neisseria meningitidis
- highest incidence b/t 6 mos. and 3 yo
- highest incidence, midwinter, early spring
- most rapidly lethal form of septic shock
When should you suspect meningococcemia?
- high fever, tachycardia, mild hypotension, signs of meningeal irritation (neck stiffness, HA, photophobia), pt appears acutely ill
Early exanthem of meningococcemia?
- will occur soon after onset
- pink 2 mm-10 mm macules/papules, sparsely distributed on trunk/lower extremities, face, palate, conjunctivae
- will see petechiae on palate of mouth
later lesions presentation of meningococcemia?
- petechiae in center of macules
- lesion become hemorrhagic w/in hours, purpura
- purpura fulminans, hemorrhagic bullae
Dx and tx for menigococcemia?
- blood cultures
- pus from nodular leion shows gram neg. diplococci
- d-dimers
tx:
cefotaxine (claforin)
ceftriaxone (rocephin)
hemodynamic stabilization
Characteristics of bacterial endocarditis?
- staph aureus, strep viridans
- proliferation of microorganisms on the endocardium of the heart
- incidence is increasing in elderly, IVDU (tricuspid), and those with prosthetic valves
History and PE findings of bacterial endocarditis?
Hx:
fever, chills/sweats. anorexia/wt loss malaise
PE:
heart murmur, arterial emboli, splenomegaly
Skin lesion findings of bacterial endocarditis?
- janeway lesions: nontender, hemorrhagic maculopapular lesions on palms and soles
- osler’s node: painful, red nodules on fingertips
- subungual splinter hemorrhage (more proximal to nail bed)
- petechial lesion: small, non-blanching, reddish-brown merciless on extremities, upper chest, mucus membranres, occur in crops, asx red streaks in nail bed
Dx and tx of bacterial endocarditis?
- pt comes in with new murmur, fever, splenomegaly, hematuria - dx is infective endocarditis until proven otherwise
- ID at risk pts and prophylax
- blood cultures
- CBC, chem panel, coags, echo
- tx:
PCN-G
Nafcillin
Gentamycin
Vanco in MRSA
Zyvox in MRSA
Characteristics of Rocky Mountain Spotted Fever (RMSF) -
bug?
when is it common?
- Rickettsia ricketsii spirochete - Rocky Mountain Wood tick
- common May thru Sept
- can be fatal if not tx, especially in elderly
hx and PE findings in RMSF?
hx:
- hx of tick bite in 60% of cases
- ask about outdoor activity
- prodrome of anorexia, irritability, malaise
PE:
- 1-2 wks after tick bite:
fever (greater than 102), chills, weakness, HA w/ photophobia
Skin lesions of RMSF?
- 49% have rash
- initially 2-6 mm, pink blanching macule begin on extremities and spread centrally: characteristically, rash begins on wrists, forearms, ankles and later on palms*
Tx of RMSF? Mortality if left untx in elderly?
- tx: doxy chloramphenical (for PG) - start abx if dx is even suspected: doxy even in kids now per CDC - less effect on teeth than tetracycline - mortality rate in elderly: 60%
Lyme Disease - cause?
- multi-stage, multi-system bacterial infection caused by the spirochete Borrelia burgdorferi from a tick bite ( blacklegged tick)
What does the rash of lyme disease look like?
- appear several days after infection, or not at all (bulls eye - sig rash)
- can last a few hours or up to several weeks
- can be very small or very large (up to 12 inches)
- can mimic such skin problems as hives, eczema, sunburn, poison ivy, flea bites
- can itch or feel hot, or may not be felt at all
- can disappear and return several weeks later
Presentation of lyme disease several days to weeks after bite?
pt usually experiences flu-like sxs such as:
- HA
- stiff neck
- aches and pains in muscles and jts
- low grade fever and chills
- fatigue
- poor appetite
- sore throat
- swollen glands
- after several months, arthritis like sxs may develop, including painful and swollen jts
How is lyme disease dx?
- difficult to dx b/c sxs are not consistnet and may imitate other conditions. The primary sx is a rash, but it may not be present in up to 10-15% of cases
- dx for lyme disease: clinical one and must be made by provider experienced in recognizing LD
- dx usually based on sxs and hx of tick bite. Testing is generally done to eliminate other conditions and may be supported through blood and lab tests, although these tests are not absolutely reliable for dx LD
Tx of lyme disease?
- oral abx are std tx for early stage lyme disease:
doxy for adults and kids older than 8
amoxicillin for adults, kids, pregnant or breast feeding - these drugs often clear the infection and prevent complications
- a 14-21 day course of ab is usually recommended, but some studies suggest that courses lasting 10-14 days are equally effective. In some cases, longer tx has been linked to serious complications
Characteristics of cellulitis?
- acute, spreading infections of dermal and subq tissues thru a skin portal
- occurs in all ages
- staph aureus and GAS common
- hx of trauma or may be unaware of wound of entry
- don’t forget dog, cat, and human bites
- common with diabetes, PVD but can happen in anyone
