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Board review - Viral infections

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Title: Board review - Viral infections


1
Board review - Viral infections
2
Rubeola (nine-day or red measles)
  • Prodromal symptoms - fever, malaise, dry
    (occasional croupy) cough, coryza, conjunctivitis
    c clear d/c, marked photophobia
  • 1-2 days p prodromal symptoms - Koplik spots on
    the buccal mucosa
  • Koplik spots - tiny, bluish-white dots surrounded
    by red halos

3
rubeola (nine-day or red measles)
  • Day 3 or 4 - blotchy, erythematous, blanching,
    maculopapular exanthem appears
  • Rash begins at the hairline and spreads
    cephalocaudally and involves palms and soles
  • Rash typically lasts 5 - 6 days
  • Can see desquimation in severe cases

4
rubeola (nine-day or red measles)
  • Patients can be systemically ill
  • Incubation period 9-10 days
  • Patients contagious from 4 days prior to the rash
    until 4 days after the resolution of the rash
  • Highly contagious - 90 for susceptible people

5
rubeola (nine-day or red measles)
  • High morbidity and mortality common in children
    in underdeveloped countries
  • Peak season is late winter to early spring
  • Potential complications - OM, PNA, obstructive
    laryngotracheitis, acute encephalitis
  • Vaccination is highly effective in preventing
    disease

6
rubeola (nine-day or red measles)
7
Rubella (german measles)
  • Little or no prodrome in children
  • In adolescents - 1-5 days of low-grade fever,
    malaise, headache, adenopathy, sore throat,
    coryza
  • Exanthem - discrete, pinkish red, fine
    maculopapular eruption - begins on the face and
    spreads cephalocaudally
  • Rash becomes generalized in 24 hours and clears
    by 72 hours

8
rubella (german measles)
  • Forchheimer spots - small reddish spots on the
    soft palate - can sometimes be seen on day 1 of
    the rash
  • Arthritis and arthralgias - frequent in
    adolescents and young women - beginning on day 2
    or 3 lasting 5-10 days
  • Up to 25 of patients are asymptomatic - serology
    testing may be necessary to establish the
    diagnosis

9
rubella (german Measles)
  • Important in establishing the diagnosis if the
    patient is pregnant or has been in contact c a
    pregnant woman
  • Peaks in late winter to early spring
  • Contagious from a few days before the rash to a
    few days after the rash
  • Incubation period 14-21 days
  • Complications - rare in childhood - arthritis,
    purpura c or s thrombocytopenia, mild encephalitis

10
rubella (german Measles)
11
Varicella (chickenpox)
  • Caused by varicella-zoster virus
  • Highly contagious
  • Brief prodrome of low-grade fever, URI symptoms,
    and mild malaise may occur
  • Rapid appearance of puritic exanthem

12
varicella (chickenpox)
  • Lesions appear in crops - typically have 3 crops
  • Crops begin in trunk and scalp, then spread
    peripherally
  • Lesions begin as tiny erythematous papules, then
    become vesicles surrounded by red halos
  • Lesions began to dry - umbilicated appearance,
    then surrounding erythema fades and a scab forms

13
varicella (chickenpox)
  • Hallmark - lesions in all stages of evolution
  • All scabs slough off 10-14 days
  • Scarring not typical unless superinfected
  • Cluster in areas of previous skin irritation
  • Puritic lesions on the skin
  • Painful lesions along the oral, rectal, and
    vaginal mucosa, external auditory canal, tympanic
    membrane

14
varicella (chickenpox)
  • Occurs year-round, peaks in late autumn and late
    winter through early spring
  • Incubation period ranges from 10-20 days
  • Contagious 1-2 days prior to rash until all
    lesions are crusted over
  • Complications - secondary bacterial skin
    infections (GAS), pneumonia, hepatitis,
    encephalitis, Reye syndrome

15
varicella (chickenpox)
  • Severe in the immunocompromised host - can be
    fatal
  • Can have severe CNS, pulmonary, generalized
    visceral involvement (often hemorrhagic)
  • Need to get varicella-zoster immunogloblin 96
    hours post-exposure to possible varicella

16
varicella (chickenpox)
17
Adenovirus
  • 30 distinct types
  • Variety of infections including conjunctivitis,
    URIs, pharyngitis, croup, bronchitis,
    bronchiolitis, pneumonia (occ fulminant),
    gastroenteritis, myocarditis, cystitis,
    encephalitis
  • Can be accompanied by a rash - variable in nature
  • Typically can see - conjunctivitis, rhinitis,
    pharyngitis c or s exudate, discrete, blanching,
    maculopapular rash

18
adenovirus
  • Can see anterior cervical and preauricular LAD,
    low-grade fever, malaise
  • Peak season is late winter through early summer
  • Contagious during first few days
  • Incubation period 6-9 days

19
Coxsackie hand-foot-and-mouth disease
  • Brief prodome - low-grade fever, malaise, sore
    mouth, anorexia
  • 1-2 days later, rash appears
  • Oral lesions - shallow, yellow ulcers surrounded
    by red halos
  • Cutaneous lesions - begin as erythematous macules
    then evolve to small, thick-walled, grey vesicles
    on an erythematous base

20
Coxsackie hand-foot-and-mouth disease
  • Highly contagious
  • Incubation period 2-6 days
  • Lasts 2-7 days
  • Peak season summer through early fall
  • If no cutaneous lesions - herpangina
  • less painful and less intense than herpes
    gingivostomatitis

21
erythema infectiosum (fifth disease)
  • Caused by Parvovirus B19
  • Affects preschool and young school aged children
  • Peak incidence in late winter and early spring,
    but it is seen year round
  • Characterized by rash - large, bright red,
    erythematous patches over both cheeks - warm, but
    non-tender

22
erythema infectiosum (fifth disease)
  • Facial rash fades, then see a symmetrical,
    macular, lacy, erythematous rash on the
    extremities
  • Resolution occurs within 3-7 days of onset
  • Transmitted by respiratory secretions, replicates
    in the RBC precursors in the bone marrow
  • Can cause aplastic crisis in patients with sickle
    cell disease, other hemogloblinopathies, and
    other forms in hemolytic anemia

23
erythema infectiosum (fifth disease)
24
roseola infantum (exanthem subitum)
  • Febrile illness affecting children 6-36 months
  • Human herpesvirus 6 is causative agent
  • Symptoms include
  • fever, usually gt39
  • anorexia
  • irritability
  • these symptoms subside in 72 hours

25
roseola infantum (exanthem subitum)
  • As fever defervenscences, usually an
    erythematous, maculopapular rash that appear on
    the trunk and then spread to the extremities,
    face, scalp, and neck
  • Occurs year-round
  • More common in late fall and early spring
  • Incubation period thought to be 10-15 days

26
roseola infantum (exanthem subitum)
27
Infectious mononucleosis
  • Acute self-limiting illness of children and young
    adults
  • Caused by EBV
  • Transmission by oral contact, sharing eating
    utensils, transfusion, or transplantation
  • Incubation period 30-50 days (shorter, 14-20
    days, in transfusion-acquired infection)
  • Dont usually see classic mono in young children

28
Infectious mononucleosis
  • Prodrome - fatigue, malaise, anorexia, HA,
    sweats, chills lasting 3-5 days
  • Symptoms
  • fever - can have wide daily fluctuations
  • pharyngitis c tonsillar and adenoidal enlargement
    c or s exudate, halitosis, palatal petechiae
  • LAD - anterior cervical and posterior cervical -
    in classic cases, generalized LAD toward end of
    wk 1

29
Infectious mononucleosis
  • Symptoms cont
  • splenomegaly - develops in 50 of patients in
    2nd-3rd wk
  • hepatomegaly in 10 of patients
  • exanthem - erythematous, maculopapular,
    rubelliform rash in 5-10 of patients

30
Infectious mononucleosis
  • Complications
  • pneumonia
  • hemolytic anemia and thrombocytopenia
  • icteric hepatitis
  • acute cerebellar ataxia, encephalitis, aseptic
    meningitis, myletis, Guillain-Barre
  • rarely myocarditis and pericarditis

31
Infectious mononucleosis
  • Complications cont
  • upper airway obstruction from tonsillar and
    adenoidal enlargement
  • seen more often in younger patients
  • children lt 5 yrs of age c obstruction are more
    likely to have secondary OM, recurrent bouts of
    OM, tonsillitis, and sinusitis
  • splenic rupture

32
Infectious mononucleosis
  • Diagnosis
  • classic finding - lymphocytosis (50 or more) c
    10 atypical lymphocytes
  • 80 or more of patients c elevated liver enzymes
  • Monospot - detects heterophil antibodies -
    specific, not as sensitive - 85 of adolescents
    and fewer younger patients
  • specific EBV antibody titers and PCR

33
Infectious mononucleosis
  • DDx
  • If fever and exudative tonsillitis predominate
  • GAS, diphtheria, viral pharyngitis
  • If LAD and splenomegaly predominate
  • CMV, toxo, malignancy, drug-induced mono
  • If severe hepatic involvement
  • viral hepatitis, leptospirosis

34
herpes simplex infections
  • Primarily involve the skin and mucous surfaces
  • Can be disseminated in neonates and
    immunocompromised hosts
  • Produces primary infection - enters a latent or
    dormant stage, residing in the sensory ganglia -
    can be reactivated at any time

35
herpes simplex infections
  • HSV-1
  • gt90 of primary infections caused by HSV-1 are
    subclinical
  • more common
  • HSV-2
  • usually the genital pathogen
  • usual pathogen of neonatal herpes

36
herpes simplex infection
  • Diagnosis
  • usually made clinically
  • can scrap base of vesicle and a special stain -
    Giemsa-stained (Tzanck)
  • ballooned epithelial cells c intranuclear
    inclusions and multinucleated giant
  • viral cultures take 24-72 hours

37
Primary herpes simplex infections
  • Herpetic gingivostomatitis
  • high fever, irritability, anorexia, mouth pain,
    drooling in infants and toddlers
  • gingivae becomes intensely erythematous,
    edematous, friable and tends to bleed
  • small yellow ulcerations c red halos seen on
    buccal and labial mucosa, tongue, gingivae,
    palate, tonsils

38
primary herpes simplex infections
  • Herpetic gingivostomatitis
  • yellowish white debris builds on the mucosal
    surfaces causing halitosis
  • vesiculopustular lesions on perioral surfaces
  • anterior cervical and tonsillar LAD
  • symptoms last 5-14 days, but virus can be shed
    for weeks following resolution

39
primary herpes simplex infections
  • Skin infections
  • fever, malaise, localized lesions, regional LAD
  • direct inoculation (usually cold sores)
  • lesions are deep, thick-walled, painful vesicles
    on an erythematous base - usually grouped, but
    may be single
  • lesions evolve over several days - pustular,
    coalesce, ulcerate, then crust over

40
primary herpes simplex infections
  • Skin infections
  • most common sites are lips and fingers or thumbs
    (herpes whitlow)
  • eyelids and periorbital tissue infection can lead
    to keratoconjunctivitis - dx by dendritic
    ulcerations on slit lamp exam
  • can lead to visual impairment - consult ophtho

41
Eczema herpeticum (kaposi varicelliform eruption)
  • Onset of high fever, irritability, and discomfort
  • Lesions appear in crops in areas of currently or
    recently affected skin (for those with atopic
    eczema or chronic dermatitis)
  • Lesions begin as pustules, then rupture and crust
    over the course of a couple of days
  • Lesions can become hemorrhagic

42
Eczema herpeticum (kaposi varicelliform eruption)
  • Multiple crops can appear over 7-10 days (like
    varicella)
  • Can be mild or fulminant, depending (in part) on
    the underlying dermatitis
  • If area of involvement is large, can be lots of
    fluid loss and potentially fatal
  • Treat promptly c acyclovir
  • Risk of secondary bacterial infections

43
Eczema herpeticum (kaposi varicelliform eruption)
44
Recurrent herpes simplex infection
  • Triggers include fever, sunlight, local trauma,
    menses, emotional stress
  • Seen most commonly as cold sores
  • Prodrome of localized burning, itching or
    stinging before eruption of grouped vesicles

45
recurrent herpes simplex infection
  • Vesicles contain yellow, serous fluid and are
    often smaller and less thick-walled than the
    primary lesions
  • Vesicular fluid becomes cloudy after 2-3 days,
    then crusts over
  • Regional, tender LAD

46
herpes zoster (shingles)
  • Caused by varicella-zoster virus
  • After primary infection, virus lies dormant in
    genome of sensory nerve root cell
  • Postulated triggers include mechanical and
    thermal trauma, infection, debilitation as well
    as immunosuppression
  • Lesions are grouped, thin-walled vesicles on an
    erythematous base distributed along the course of
    a spinal or cranial nerve root (dermatome)

47
herpes zoster (shingles)
  • Lesions evolve from macule to papule to vesicle
    then crusted over a few days
  • May have associated nerve root pain - not common
    in pediatrics - usually short-lived unless it
    involves a cranial nerve root dermatome
  • /- fever or constitutional symptoms
  • Regional LAD common

48
herpes zoster (shingles)
  • Thoracic, cervical, trigeminal, lumbar, facial
    nerve dermatomes (order of frequency)
  • If cranial nerve involvement - prodrome of severe
    HA, facial pain, or auricular pain prior to the
    eruption
  • Affected patients can transmit varicella, but
    less of a problem b/c lesions are often covered
    by clothing and the o/p is not involved in most
    cases

49
herpes zoster (shingles)
50
gianotti-crosti syndrome
  • Papular acrodermatitis
  • Associated c amicteric hepatitis B, EBV,
    echovirus, coxasckievirus, parainfluenza virus,
    CMV, and RSV
  • Most patients between 1-6 years old (range 3
    months to 15 years)
  • Prodrome of low-grade fever and malaise
  • May be associated c generalized LAD,
    hepatomegaly, URI symptoms, and diarrhea

51
gianotti-crosti syndrome
  • Lesions appear within a few days - discrete,
    firm, lichenois papules c flat tops ranging from
    1-10 mm (larger in infants and smaller in older
    children)
  • Papules can be flesh colored, pink, red, dusky,
    coppery, or purpuric
  • Distributed symmetrically over extremities
    (including palms and soles), buttocks, and face -
    relative sparing of the trunk and scalp
  • No mucosal involvement and non-purtitic

52
gianotti-crosti syndrome
  • Usually clears in 2-3 weeks, but can last for 8
    weeks or more
  • Lab studies are generally non-specific, but liver
    enzymes should be obtained and if abnormal -
    hepatitis B or EBV serology should be done
  • Treatment is supportive
  • Steroid creams contraindicated b/c they can make
    the rash worse

53
gianotti-crosti syndrome
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