Board review - Viral infections

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Board review - Viral infections
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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

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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

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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

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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

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rubeola (nine-day or red measles)
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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

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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

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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

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rubella (german Measles)
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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

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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

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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

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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

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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

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varicella (chickenpox)
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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

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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

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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

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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

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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

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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

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erythema infectiosum (fifth disease)
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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

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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

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roseola infantum (exanthem subitum)
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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

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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

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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

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Infectious mononucleosis

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

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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

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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

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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

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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

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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

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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

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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

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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

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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

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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

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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

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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

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Eczema herpeticum (kaposi varicelliform eruption)
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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

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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

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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)

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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

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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

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herpes zoster (shingles)
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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

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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

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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

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gianotti-crosti syndrome