Approach to Fever in Infants and Children

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Approach to Fever in Infants and Children

• DR. ELIZABETH KE
• MD, DCH, Ph D, FIAP

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DEFINITION OF FEVER

• Fever is an elevation of body temperature that
  exceeds the normal daily variation, in
  conjunction with an increase in hypothalamic set
  point

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Fever Phobia

• Fever is the most common pediatric complaint,
  second only to routine care for clinic visits,
  and the most common reason kids are brought to
  the ER.
• Some feel true fever is harmful all thought
  brain damage gt41ºC(106ºF).
• 5-20 have no localizing signs with no history to
  explain the fever.
• The majority of kids with fever do not have a
  serious illness, although a small percentage
  harbor or may develop a serious bacterial
  infection.

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NORMAL BODY TEMPERATURE

• Maximum normal oral temperature
• At 6 AM 37.2
• At 4 PM 37.7
• Normal circadian rhythm, which is highest (up to
  2ºC, 3ºF) 6pm and lowest at 6am. This accounts
  for increased volume of ER visits that peaks in
  the evening. Most true fevers follow this
  diurnal pattern

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True Fever

• Pyrogens
• Exogenous pyrogens
• Bacteria, Virus, Fungus, Allergen,
• Endogenous pyrogen
• Immune complex, lymphokine,
• Major EPs IL1, TNF, IL6

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HYPERTHERMIA

• Heat production exceeds heat loss, and the
  temperature exceeds the individuals set point,
  Normal causes of temperature elevation include
  physical activity, ovulation, and environmental
  temperature.
• Heat stroke Exercise, Anticholinergic
• Drug induced Cocaine, Amphetamine,MAO inh.
• Neuroleptic malignant syndromePhenothiazine
• Malignant hyperthermia Inhalational anesthetics
• Endocrinopathy throtoxicosis, pheochromocytoma

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Reliable Temperature Measurement

• All measurements are estimates of the bodys true
  core tempcentral circulationaorta and pulmonary
  artery.
• RECTALgold standard
• Esophagealaccurate but impractical
• Tactile and axillaryinaccurate, varies
  considerably with environmental temperature
• Tympanicinaccurate in age lt3 years
• Newborns- same as axillary temp.

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Benefits of fever

• The hypothalamus will not allow the temp to rise
  above 41.5ºC(107ºF).
• WBCs work best and kill the most bacteria at
  38-40ºC(100.4-104ºF).
• Neutrophils make more superoxide anion, and there
  is more and increased activity of interferon.
• Coxsackie and polio virus replication is directly
  inhibited.

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FEVER

• Associated Symptoms
• Shaking chills
• Ear pain Ear drainage, Hearing loss
• Visual and Eye Symptoms
• Sore Throat
• Chest and Pulmonary Symptoms
• Abdominal Symptoms
• Back pain, Joint or Skeletal pain

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Fever Patterns

• Sustained (Continuous) Fever
• Intermittent Fever (Hectic Fever)
• Remittent Fever
• Relapsing Fever
• Tertian Fever
• Quartan Fever
• Days of Fever Followed by a Several Days Afebrile
• Pel Ebstein Fever
• Fever Every 21 Day

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Approach to Fever

• Physical Examination
• Vital Signs
• Neurological Exam.
• Skin Lesions, Mucous Membrane, Petichiae
• Eyes
• ENT
• Lymphadenopathy
• Lungs and Heart
• Abdominal Region (Hepatomegaly, Splenomegaly)
• Musculoskeletal

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Approach to Fever

• Assess the extent and severity of the
  inflammatory response to infection
• Determine the site(s) and complications of organ
  involvement by the process
• Determine the etiology of the infectious disease

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Fever without a source/ focus (FWS/ FWF)

• 5 to 20 of febrile children have no localizing
  signs on PE and nothing in the history to explain
  the fever. By definition, less than 7 days.
• FWS (like fever) is most common in children
  younger than age 5, with a peak prevalence
  between 6 and 24 months of age.
• Those lt6 months retain protective maternal
  antibodies against common organisms, while those
  18-24 months old are more immune competent, and
  are at a lower risk of developing bacteremia

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PUO/FUO

• Classic FUO
• Nosocomial FUO
• Neutropenic FUO
• HIV-Associated FUO

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Classic FUO

• Definition
• Fever of 38.3 C or higher on several occasions
• Fever of more than 3 weeks duration
• Diagnosis uncertain, despite appropriate
  investigations after at least 3 outpatient visits
  or at least 3 days in hospital

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Causes of Classic FUO

• Infections 22-58
• Neoplasms up to 30
• Noninfectious inflammatory diseases up to
  25
• Miscellaneous causes up to 25
• Undiagnosed up to 30

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FUO

• Localized pyogenic infections
• Intravascular infections
• Systemic bacterial infections (Tuberculosis,
  Brucellosis,)
• Fungal infections
• Viral infections
• Parasitic infections

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Non Infectious Causes

• Collagen vascular/ hypersensitivity diseases
• Lupus
• Stills disease
• Temporal arteritis (Giant cell arteritis)

• Granulomatouse diseases
• Crohns disease
• Sarcoidosis
• Idiopathic granulomatouse disease

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Drug Fever

• PATHOGENEGIS
• Contamination of the drug with a pyrogen or
  microorganism
• Pharmacologic action of the drug itself
• Allergic (hypersensitivity) reaction to the drug

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Factitious fever

• Diagnosis should be considered in any FUO,
  especially in
• Young women
• Persons with medical training
• If the patients clinically well
• Disparity between temperature and pulse
• Absence of the normal diurnal pattern

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Work up of Fever

• Blood , Urine,
• Cultures
• Serology
• Imaging
• Biopsies

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Investigations

• 1-3 days Routine Blood Urine tests
• 4-6 days Cultures, Imaging
• 7-14 days Serology
• gt 14 days - Biopsies

• Well child may wait up to 5 days for viral
  fevers and exanthems to evolve
• Sick child Empiric antibiotic therapy

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Acute Phase Reactants

• Altered hepatocyte function (Acute phase
  reactants)
• C reactive protein(increased)
• Serum amyloid A(increased)
• Fibrinogen(increased)
• Fibronectin(increased)
• Haptoglobin(increased)
• Ceruloplasmin(increased)
• Ferritin(increased)
• Albumin(decreased)
• Transferrin(decreased)

• Metabolic changes
• Negative nitrogene balance
• Loss of body weight
• Altered synthesis of hormones
• Hematologic alterations
• Leukocytosis
• Thrombocytosis
• Decreased erythrocytosis

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Altered Fever Response

• Fever may not be present despite infection in
• Newborn
• Elderly
• Uremia
• Significant malnourished individual
• Taking corticosteroids

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Neonatal

• PE is felt to be unreliable in detecting many
  serious bacterial infections. Meningitis should
  always be consideredup to 10 appear well, only
  15 have a bulging fontanelle, and 10-15 have
  nuchal rigidity. So, a high index of suspicion
  is important!!! 20 will not have fever
  initially.
• Hyperthermia or hypothermia
• Lethargy or irritability
• Poor feeding or vomiting
• Apnea, Dyspnea
• Jaundice
• Hypotension
• Diarrhea or abdominal distension
• Bulging fontanelle
• Seizures
• Bleeding manifestations, DIC

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Case study

• 2 month old infant fever 5 days
• Febrile
• Poor feeding
• Rash over the body
• So what ?

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Infants 1 to 3 months

• Infants who are toxic and febrile have a much
  higher risk of serious bacterial infection. They
  should be admitted, have a full sepsis workup,
  and given antibiotics/antivirals?Ampicillin and
  Cefotaxime.
• Infants who are nontoxic and febrile who meet all
  Rochester criteria can safely be treated as an
  outpatient. Generally, 1-2.9 of children
  meeting these criteria will develop a serious
  bacterial infection, 0.7 bacteremia, 0.14
  meningitis.

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Infants 1 to 3 months

• Rochester Criteria/Low Risk Criteria
• Nontoxicmost critical and difficult
• Previously healthy, not low birth weight
• No focal bacterial infection on PE except Otitis
  Media
• WBC 5,000-15,000/mm3 (normal)
• Bandslt1500/mm3 (normal)
• Normal urinalysis, including gram stain
• If diarrhea, must be non-bloody and WBClt5/hpf.
• If respiratory symptoms present, normal CXR
• Negative predictive value 98.9

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Infants 1 to 3 months

• If all of the criteria are met, then there are 2
  options for outpatient management
• 1) Blood, Urine Cultures, LP, Ceftriaxone
  50mg/kg IM (to 1g), and return for reevaluation
  within 24 hours.
• 2) Blood, Urine Cultures and careful
  observation.
• Parents should have mature judgement, can return
  within 30 minutes and have a thermometer and a
  phone.
• IF NO LP IS DONE, DO NOT GIVE CEFTRIAXONE AS IT
  WILL COMPROMISE F/U IF THE PATIENT IS STILL
  FEBRILE

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Infants 1 to 3 months

• Follow-up of low risk infants
• If all cultures negative afebrile, well
  appearing?Careful observation
• Blood cultures negative well appearing,
  febrile?Careful observation, may consider second
  dose of Ceftriaxone
• Blood culture positive?admit for sepsis workup
  and parenteral antibiotics pending results
• Urine culture positive if persistent
  fever?admit for sepsis workup, parenteral
  antibiotics pending results. If afebrile and
  well?outpatient antibiotics

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Case Study

• 3 year old child
• Treated for fever
• 3rd day developed rash over legs
• Thought as drug allergy
• Collapsed in the evening, hypotension
• So what ?

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Case study

• 2 year old child with fever, cough
• Developed inconsolable crying in the night
• Refusal of feed
• So what ?

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Infants 3 to 36 months

• UA with micro, CBC with differential, Blood
  Cultures
• LP if meningeal signs, not wanting to be held or
  moved, petechiae, purpura or toxic.
• Antimicrobials
• OM or pneumonia cover for pneumococcus,
  non-typable H. flu and Moraxella
  amoxicillinaugmentin, ceftriaxone
• URI or no focus cover for pneumococcus and
  menigococcus amoxicillin(80-100mg/dg/day),
  ceftriaxone
• Pneumococcemia promptly reassess, if well,
  should at least treat with 1 dose ceftriaxone.
• PCV-7 gt97 protection, thus all pneumococcal
  sepsis will decrease by 90. So CBC and
  antimicrobials for this age group is becoming
  less critical.

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Infants 3 to 36 months

• Infant sepsis syndrome
• Age 3-36 months
• Fevergt39ºC
• ANCgt10,000
• If a child meets all 3 criteria, he has a 3 risk
  for pneumococcemia. If untreated, 3 will
  progress to meningitis.
• Bacteremia risk peaks at 8-12 months
• Pneumococcal sepsis peaks at 1 year, then drops
  off
• Pneumococcal meningitis peaks at 3-5 months
• OM, sinusitis, pneumonia, response to
  antipyretics, and social status do not
  significantly alter risk.
• Other causes HHV6(15), UTI(girls 3, boys
  0.6), menigococcemia(0.1), Salmonella(0.2), H.
  influenza(0.05), Enterovirus(July?October).

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Occult Bacteremia

• Empiric antibiotics should be targeted against S.
  pneumoniae, N. meningitidis, and H. influenza
• Amoxicillin
• Augmentin, Bactrim, 2nd or 3rd gen Cephalosporins
• Single dose Ceftriaxone 50-75mg/kg
• Followup is essential!

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Risk of Occult Bacteremia
Low Risk Age gt3yr Temp lt39.4ºC WBC gt5000 and lt15,000 High Risk lt2yr gt40ºC(104ºF) lt5000 or gt15,000 Hx of contact with H. Flu or N. meningitidis

• OB has a low prevalence, so even though WBC is a
  sensitive and specific screening test, it has a
  low PPV. So the test does not discriminate
  between children who have FWS who are bacteremic
  and those who are not.
• Therefore, blood culture is the gold
  standard?still has a high number of false
  positives, take 24-48hrs, and most cases of
  occult pneumococcal bacteremia clear without
  treatment.

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Pneumococcal

• Streptococcus pneumonia is responsible for 2/3 to
  ¾ of all cases.
• Peak prevalence between 6 and 24 months
• Association with high fever(39.4ºC or 103ºF)
• High WBC count(gt15,000)
• Absence of evident focal soft tissue infection.
• Neisseria meningitidis, Haemophilus influenzae
  type b, and salmonellae account for most of the
  remaining cases.

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Antibiotics

• 5 of children with FWS have OCCULT BACTEREMIA
• The presence of a positive blood culture in kids
  who look well enough to be treated as outpatients
  and in whom the positive results are not
  anticipated.

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Antipyretic

• Acetaminophen is generally a first-line
  antipyretic due to being well tolerated with
  minimal side effects.
• Pediatric dose 10-15mg/kg q4-6h (2400mg/day)
  adult 650mg q 4 h(4000mg)
• Can be hepatotoxic in high doses can upset
  stomach

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Others

• Aspirin
• Ibuprofen
• Mefenamic acid
• Nimuselide _ NO
• Combinations - NO

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CLINICAL PEARLS

• Dont give aspirin to children under 18 years
  (Reyes Syndrome)
• Try tepid water sponge bath (80F or 27C)
• remove blankets and heavy clothing keep room at
  comfortable temp, Avoid ice and alcohol