Bacterial and Viral infections Flashcards Preview

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Flashcards in Bacterial and Viral infections Deck (56)
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1
Q

Characteristics of impetigo? What may follow impetigo?

A
  • 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
2
Q

What will you see on PE of impetigo?

A
  • 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
3
Q

Tx of impetigo?

A
  • 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)
4
Q

Characteristics of meningococcemia - Bug?

What ages?

A
  • Neisseria meningitidis
  • highest incidence b/t 6 mos. and 3 yo
  • highest incidence, midwinter, early spring
  • most rapidly lethal form of septic shock
5
Q

When should you suspect meningococcemia?

A
  • high fever, tachycardia, mild hypotension, signs of meningeal irritation (neck stiffness, HA, photophobia), pt appears acutely ill
6
Q

Early exanthem of meningococcemia?

A
  • 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
7
Q

later lesions presentation of meningococcemia?

A
  • petechiae in center of macules
  • lesion become hemorrhagic w/in hours, purpura
  • purpura fulminans, hemorrhagic bullae
8
Q

Dx and tx for menigococcemia?

A
  • blood cultures
  • pus from nodular leion shows gram neg. diplococci
  • d-dimers

tx:
cefotaxine (claforin)
ceftriaxone (rocephin)
hemodynamic stabilization

9
Q

Characteristics of bacterial endocarditis?

A
  • 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
10
Q

History and PE findings of bacterial endocarditis?

A

Hx:
fever, chills/sweats. anorexia/wt loss malaise
PE:
heart murmur, arterial emboli, splenomegaly

11
Q

Skin lesion findings of bacterial endocarditis?

A
  • 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
12
Q

Dx and tx of bacterial endocarditis?

A
  • 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
13
Q

Characteristics of Rocky Mountain Spotted Fever (RMSF) -
bug?
when is it common?

A
  • Rickettsia ricketsii spirochete - Rocky Mountain Wood tick
  • common May thru Sept
  • can be fatal if not tx, especially in elderly
14
Q

hx and PE findings in RMSF?

A

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

15
Q

Skin lesions of RMSF?

A
  • 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*
16
Q

Tx of RMSF? Mortality if left untx in elderly?

A
- 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%
17
Q

Lyme Disease - cause?

A
  • multi-stage, multi-system bacterial infection caused by the spirochete Borrelia burgdorferi from a tick bite ( blacklegged tick)
18
Q

What does the rash of lyme disease look like?

A
  • 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
19
Q

Presentation of lyme disease several days to weeks after bite?

A

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
20
Q

How is lyme disease dx?

A
  • 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
21
Q

Tx of lyme disease?

A
  • 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
22
Q

Characteristics of cellulitis?

A
  • 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
23
Q

PE findings of cellulitis?

A
  • warmth, erythema, edema and tenderness of affected area
  • the margin of cellulitis will NOT be palpable
  • cellulitis characterized by violaceous color and bullae suggets infection with strep pneumoniae (pneumococcus)
24
Q

Dx of cellulitis?

A

no workup is reqd in uncomplicated cases that meet the following criteria:

  • small area of involvement
  • minimal pain
  • no systemic signs of illness (fever, chills, dehydration, alt. mental status, tachypnea, tachycardia, hypotension)
  • no RFs for serious illness

if complicated with signs of systemic involvement:
CBC
blood cultures
chem panel

25
Q

Tx of cellulitis?

A
  • empiric coverage for staph and strep

mild:
bactrim, clinda, Doxy: cover MRSA
Keflex
Dicloxacillin

complicated: 
hospitalization for IV abx (cover MRSA plus)
- Ancef (cephalexin)
- ceftriaxone (rocephin)
- ampicillin-sulbactam
- zyvox
26
Q

Characteristics of Erysipelas? What diff it from cellulitus?

A
  • Group A beta hemolytic strep
  • it begins as small erythematous patch that progresses to a fiery-red, indurated, tense and shiny plaque, known as *St. Anthony’s fire
  • lesion classically exhibits raised sharply demarcated advancing margins, this differenciates it from cellulitis. Cellulitis has no lymphatic component and exhibits indiscreet margins
  • inflammation, such as warmth, edema, and extreme tenderness
  • lymphatic involvement often is manifested by overlying skin streaking and regional lymphadenopathy. More severe infections may exhibit numerous vesicles and bullae
27
Q

Prodrome and progression of erysipelas?

A
  • malaise, chills, fever

- several spots of redness and tenderness, increase in size to form a tense, red, hot, uniformly elevated shiny patch

28
Q

Tx of eryispelas?

A
  • PCN G
  • PCN VK
  • Dicloxacillin (Dynapen)
  • Keflex (cephalexin)
  • clindamycin
  • erythromycin
  • may need alangesics for pain
29
Q

Human bites - what bug should you think of?
Common in what pops?
Types of injury?
lab and imaging studies done?

A
  • think anaerobes
  • common in young males:
    closed fist injuries, chomping type injury, puncture wound on head
  • routine lab tests: generally not indicated b/c the injured pop is usually young and healthy, dx of infection is clinical
  • xray: osteomyelitis, metacarpal head fracture
30
Q

Tx of human bites?

A
  • Augmentin
  • Moxifloxin (Avelox): over 18
  • clindamycin
  • Don’t forget a tetanus shot (give in opp. extremity)
  • pt must f/u in 1-2 days
31
Q

What hold risk for higher infection: cat or dog bite? What should be considered as tx for all of these wounds?

A
  • cats - higher risk of infection b/c more penetrating wounds - sharp teeth carry Pasteurella multocida
  • consider tetanus and rabies prophylaxis for all wounds
32
Q

Tx for dog and cat bites?

A
  • inspect, debride, irrigate:
  • primary closure for wounds that can be cleaned effectively but more often left open to heal
  • facial wounds can be closed
  • lower extremity wounds need delayed closure
  • pt f/u in 1-2 days
  • abx tx:
    augmentin
    erythromycin
    bactrim DS, Septra DS
    clinda
    cipro
33
Q

Characteristics of necrotizing fasciitis? Where does it move along? What bacteria is present?

A
  • referred to as hemolytic streptococcal gangrene
  • progressive, rapidly spreading, inflammatory infection located in deep fascia, with secondary necrosis of subq tissues
  • moves along deep fascial plane
  • have anaerobic bacteria present, usually in combo with aerobic gram - organisms
  • GAS, staph, alone or together are frequently the initiating infecting bacteria
  • mean age of 38-44
34
Q

Hx that is suspicous of necrotizing fasciitis?

A
  • trauma, or recent surgery to the involved area is often present
  • insect bites, surgical procedures (infectious), IM injections and IV infusions
  • Idiopathic cases are not uncommon
  • a sudden onset of pain and swelling at site of trauma or recent surgery
  • over next several hours to days - local pain progresses to anesthesia
35
Q

PE findings of necrotizing fasciitis?

A
  • begins with area of erythema that quickly spreads over a course of hours to days
  • redness quickly spreads
  • the margins of infection move out into normal skin w.o being raised or sharply demarcated
  • with progression - dusky or purplish skin discoloration near the site of insult
  • multiple identical patches develop, produce a large area of gangrenous skin as the erythema continues to spread
  • if skin is open, gloved fingers can pass easily b/t 2 layers and may reveal yellowish-green fascia
36
Q

Most impt signs of necrotizing fasciitis?

A
  • tissue necrosis
  • putrid d/c
  • bullae
  • severe pain
  • gas production
  • rapid burrowing through fascial planes
  • lack of classic tissue inflammatory signs (dying tissue)
37
Q

Workup for necrotizing fasciitis?

A
  • CBC with diff
  • chem panel
  • blood and tissue cultures
  • UA
  • ABGs
  • xray
  • CT
  • bx best to use when dx
38
Q

Tx of necrotizigng fasciitis?

A
  • aggressive abx
  • hemodynamic stabilization
  • surgical consult for debriding
  • infectious disease specialist
  • hyperbaric specialist
39
Q

Abx used in tx of necrotizing fasciitis?

A
  • ceftriaxone (rocephin)
  • PCN-G
  • clindamycin
  • flagyl
  • gentamycin
  • chloramphenicol
  • ampicillin
40
Q

Characteristics of Hidradenitis suppurativa? Predisposing factors?Common sites?

A
  • chronic, suppurative (production of pus) disease of apocrine gland-bearing skin
  • onset from puberty to climacteric
  • predisposing factors: obesity, genetic disposition to acne, apocrine duct obstruction
  • common sites:
    axilla
    anogenital region
41
Q

Hx and PE of Hidradenitis suppurativa?

A
hx: 
intermittent pain and marked pt tenderness related to abscess formation
 PE: 
- very tender, red inflammatory nodules
- may drain purulent/seropurulent material
- open comedones/double comedones
- fibrosis/bridge scars
- lesions may become infected
42
Q

Tx of Hidradenitis suppurativa?

A
combo of:
- intralesional glucocorticoids (triamsinolone)
- PO steroids: predisone
- surgery: I&D abscess is last resort
- oral abx:
erythromycin
tetracyclin
minocycline
- isotretinion
43
Q

Viral causes of derm manifestations?

A
  • HIV/AIDS: kaposi’s, oral hairy leukoplakia (precancerous)
  • HSV
  • HPV - condyloma Acuminata
  • molluscum contagiosum
  • primary varicella
  • varicella-zoster (shingles)
44
Q

HSV - cause and sxs?

A
  • caused by HSV 1 and 2
  • can occur anywhere on the body
  • can be asx or sx
  • can be spread by direct contact or fluid
    sxs occur 3-7 days after contact:
  • tenderness
  • pain
  • mild paresthesias or burning
  • grouped vesicles on an erythematous base
  • centers become depressed
  • crusts form and heal w/o scarring
  • the virus enters the nerve endings, runs through peripheral nerves to the dorsal root ganglia
45
Q

Diff HSV infections - where do they manifest? Cause of onset?

A
- recurrent infection/ reactivation of the virus: 
due to  - local skin trauma esp UV, systemic changes: fever, infection, stress
- type 1:
oral and labial HSV
whitlow-fingers
- type 2: Genital herpes
primary
recurrent
may mimic zoster in sacral distributions
46
Q

Dx of HSV?

A
  • inspection (usually enough for dx)
  • Tzanck smear
  • direct immuno fluorescence ab
  • culture (viral)
47
Q

Tx of HSV?

A
  • cool compresses
  • air or heat lamp drying of lesions
  • penciclovir (denavir) - topical agent
  • famciclovir (famvir) or valacyclovir (valtrex)
  • acyclovir: less expensive alt
  • pain control PRN
48
Q

Characteristics of Chicken pox? How does rash appear?

A
  • highly contagious: 2 days b/f onset of rash, until all lesions have crusted
  • appear on face and scalp, spread inferiorly to trunk (centripetal)
  • vesicles appear as small “drops of water” on a red base. Delicate “dew drops on a rose petal” like lesion
  • pruritic
  • becomes pustules and crusts over
49
Q

Tx of Varicella (Chicken Pox)?

A
  • usually is self limiting
  • sx: benadryl for pruritus, tylenol for fever
  • systemic: acyclovir (zovirax)
50
Q

Characteristics of Herpes Zoster (shingles)?

A
  • more than 60% are older than 50 yo
  • involves dermatomes
  • reactivation of varicella virus in cutaneous nerves from earlier varicella
  • triggering factors
  • unilateral
  • very painful
  • flu like prodrome
51
Q

Skin lesion- common areas and complications?

A
  • common areas: thoracic, trigeminal, lumbosacral, cervical

skin lesions:

  • papules to vesicles-bullae
  • pustules to crusts
  • erythematous, edematous base with superimposed clear vesicles, sometimes hemorrhagic
  • vesicle is oval or round
  • can have regional lymphadenopathy

complications:
postherpetic neuralgia
temporary motor paresis

52
Q

Tx of shingles?

A
  • famvir, valtrex, or acyclovir 800 mg 5xd for 7-10 days
  • oral steroids controversial +/-
  • abx cream to prevent secondary infections
  • if extremely painful: burrow’s soln or cool tap water compresses, ultram PO
53
Q

Genital warts:

cause? Characteristics of the warts?

A
  • condyloma acuminata/venereal warts
  • papilloma virus
  • evidence of relationship with genital cancer is overwhelming
  • spread rapidly over moist areas
  • small papules to large verrucous lesions
  • warts may extend into vaginal tract, urethra, rectum
  • genital warts in kids (if less than 1 - probably infected during birth)
    est that 50% are from sexual abuse, can be obtained w/o sexual, auto-inoculation
54
Q

Tx of genital warts?

A
  • all genital warts should be tx
  • podophyllum, 20% in tincture of benzoin varies in effectiveness: tx small areas, notify pathologist if sending bx previously tx
  • trichloroacetic acid 25-50% (particularly helpful for vaginal)
  • cryosurgery
  • carbon dioxide laser
  • electrosurgery
  • tx doesn’t insure elimination of wart virus from area
55
Q

Cause of molluscum contagiosum? Spread, common areas?

A
  • pox virus
  • discrete, 2-5 mm, umbilicated, dome-shaped papules
  • spread by autoinoculation, scratching, or touching a lesion
  • common on face, trunk, extremities in kids
  • common in genital and pubic areas in adults
56
Q

Tx of molluscum contagiosum?

A
  • tx: not necessary to tx in children, as they are self limited
  • curettage
  • cryosurgery
  • TCA/podophyllin
  • retin A cream
  • cantharidin