Fever and Infections of Infancy and Childhood

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					                        Fever and Infections of Infancy and Childhood
                  Delane Shingadia, Senior Lecturer in Paediatric Infectious Diseases
Objectives
What causes fever
How to measure of body temperature
Signs and symptoms of infection in children
Diagnosis, investigation and management of febrile child
Fever of unknown origin
Use of antipyretics and antibiotics

What is Fever?

Temperature Regulation
Humans are homeothermic (body temperature maintained within narrow limits)
Thermostat that modulates heat production and heat loss to maintain core temperature within narrow limits

Stability of core temperature

Thermoregulatory Centre in the Brain

Hypothalamic thermostat

Heat gain and loss

Too hot. Too cold

Changes in External Temperature

What causes fever?
Fever is a centrally regulated rise in body temperature in response to a pathologic stimulus
Set point is raised and therefore equilibrium is upset
Caused by ‘endogenous pyrogens’ or products of the inflammatory cell response

Pyrogens and fever

But remember that not all fevers are due to infections (endogenous pyrogens)
Malignancy e.g. leukaemia
Inflammatory diseases e.g. rheumatoid arthritis
Unknown                                               Mercury Thermometers
                                                      Most accurate
Measurement of Body Temperature                       Take 2-4 minutes to read
Core temperature                                      Risk of breakage and mercury ingestion
         rectal thermometer                           Mouth, rectum or armpit
         0.5 ºC above oral and 1-1.5ºC above axillary
         Most accurate                                Electronic Thermometers
Oral temperature (mouth)                              Quicker to read (30 secs)
Axillary temperature (armpit)                         Reasonably accurate when used by someone with experience
Ear temperature                                       May underestimate core temperature
Forehead temperature
                                                      Infrared Ear thermometers
Relative size of body shell                           Popular
                                                      Less accurate
Skin Temperature measurements                         Estimate temperature of tympanic membrane
Temperature-sensitive crystals
Inaccurate because they only estimate skin temp and not core temp

Fever in Children
Lower limit of 38.0°C (rectal)
However serious and life-threatening infections can occur with normal to low temperatures
Young infants/ neonates may be hypothermic with infection

Causes of Fever in Children
Bacterial infection     Fungal infection
Viral infection         Parasitic infection
Common Causes of Infection in Childhood
Bacteria
                                   Virology
   Gram Positive bacteria
                                       RSV
        Staphylococcus aureus
                                       Varicella
        Streptococcus pneumoniae
                                       Rotavirus
   Gram Negative bacteria
                                       Adenovirus
        Bordetella pertussis
                                       Enterovirus
        Haemophilus influenza
                                       Herpesvirus
        Neisseria meningitidis
                                       Parvovirus
        Salmonella spp.

Fever in children
65% of children <2 years will visit a physician for an acute febrile illness
19-30% of encounters in clinical practice
Most commonly caused by self-limited viral illness and localized bacterial infection, but may be presenting feature of
something more serious infection e.g. meningitis

Diagnosis of Febrile Visits

History
How many days of fever?                                                More History
How high was fever?                                                    Anyone else sick in the family?
Any other symptoms?                                                    Contact with animals?
        Cough/runny nose/difficulty in breathing                       Any history of travel?
        Irritability/fits                                              Past medical history
        Diarrhoea/vomiting                                             Family history
        Pain on passing urine                                          Drug history
        Tugging at ears
        Limping/not weight-bearing
        Skin rash

Examination
Does child look well or unwell?
Ear, nose, and throat
Respiratory system
Cardiovascular system including measurement of pulse and blood pressure
Abdominal system for palpable liver or spleen
Skin examination for rash
Bones and joints for swelling, redness or pain
Central nervous system including neck stiffness, irritability or full fontanelle

Newborns and children <1 year age
May have nonspecific symptoms such as poor feeding or lethargy
May have minimal symptoms and signs
May not have fever (may be hypothermic)
May fall ill rapidly

Fever in Children – different clinical spectrum
Fever with source or clinical signs
        Common infections
        Rash
        Lymphadenopathy
        Hepatosplenomegaly
Toxic appearing child or septic shock
Fever without source
Fever of unknown origin

Common Causes of Fever in Children
Ear infections (otitis media)
Throat/upper respiratory tract infections (pharyngitis, tonsilitis, laryngitis)
Meningitis
Lower respiratory tract infections (pneumonia/empyema)
Abdominal infections (gastroenteritis)
Urinary tract infections                                    Skin infections (cellulitis/impetigo)
Bone and joint infections (arthritis/septic arthritis)
Ear Infections
Two year old boy with left ear pain                               Fever with lymphadenopathy
                                                                  Infections
Cellulitis                                                        Viral (HIV, EBV, CMV)
14 year old boy with left eye swelling and fever                      Tuberculosis
                                                                      Toxoplasmosis
Meningitis                                                        Connective tissue disorders (JRA, SLE)
                                                                  Neoplasm (leukaemia, lymphoma)
Tonsillitis                                                       Drug reaction (phenytoin)
Six year old girl with difficulty swallowing                      Miscellaneous (sarcoidosis, histiocytosis)
Urinary Tract Infections                                          Infectious Mononucleosis
9 month old girl with fever and poor feeding                      13 year old boy with lymphadenopathy
Pneumonia                                                         Pictures of infectious mononucleosis
10 year old boy with fever, cough and difficulty in breathing
                                                                  Fever with hepatosplenomegaly
Osteomyelitis                                                     Infectious
4 year old not weight-bearing and limping for 3 days                       Epstein-Barr virus
                                                                           Cytomegalovirus
Fever and Rash                                                             Toxoplasmosis
Parvovirus infection (slapped cheek)                                       Human immunodeficiency virus (HIV)
                                                                           Hepatitis viruses
Viral Exanthems                                                            Tuberculosis
Measles                                                                    Catscratch disease
Chickenpox                                                        Noninfectious
                                                                           Haematological malignancy
Kawasaki Disease                                                           Connective tissue disorders
Unusual Cause of Fever and Rash
Swollen knee of a youth with Lyme arthritis

‘Toxic Appearance’ or septic shock
Bacteria in blood stream release toxins that cause blood vessels to dilate and leak
Clinical picture consistent with the sepsis syndrome
         Lethargy/sleepy
         Cold and poorly perfused extremities
         Low blood pressure/rapid pulse
         Hyperventilation
         cyanosis

Spectrum of Septic Shock
Severe sepsis (altered organ perfusion)
Septic shock (hypotension and poor capillary refill)
Multiorgan dysfunction syndrome (coagulopathy, respiratory distress, renal failure, hepatobiliary dysfunction and
neurological dysfunction

Neisseria meningitidis Meningitis/Septicaemia

Fever without a source
Acute febrile illness in which the aetiology of the fever is not apparent after a careful history and examination
Accounts for 14% of children with fever
May be difficult to differentiate children with viral infection versus occult bacteraemia

Fever of unknown origin
Fever for at least 7 days
Negative history, examination and laboratory testing
Cause
        Infectious 40-50%
        Collagen-vascular 10-20%
        Neoplasms 5-10%
        Undiagnosed 20-30%
Infectious causes of FUO
Systemic viral infections (EBV, CMV)
Urinary tract infection
Tuberculosis
Bacterial endocarditis
Brucellosis
Cat scratch disease
Abdominal abscess
Rarer causes

Prolonged Fever

Initial Investigations
Full blood count and differential white cell count (neutrophils, lymphocytes)
C-reactive protein
Bacterial blood culture
Urine microscopy and bacterial culture
Chest x-ray
Throat swab/ nasopharyngeal aspirate
Lumbar puncture for cell count and bacterial culture

Treatment of Fever
External cooling
        Tepid sponge or bath
Paracetamol (acetaminophen)
        Anti-pyretic only
        Very safe except with overdose
Aspirin and ibuprofen (non-steroidal anti-inflammatory drugs)
        Antipyretic and anti-inflammatory
        Inhibit prostaglandin synthesis
        Side effects (gastritis, bleeding, bronchospasm)

When to use anti-pyretics?
Patient uncomfortable because of fever
Risk of febrile convulsions
Risk of clinical deterioration
Critically ill children
High risk for cardiac or respiratory decompensation
Very high fevers >40°C

When to use antibiotics?
Very ill child with severe disease example septic shock
Suspected focal bacterial infection e.g pneumonia, meningitis
Very young babies/infants (usually <1 year old) with fever but no focus
Immunosuppressed children with fever e.g. HIV, leukaemia
Child with petechiael rash

Fever in Children: conclusion
Many bacterial and viral causes of fever in children
Need to obtain a good history and thorough examination to determine nature of infection
Younger infants may not have obvious signs or symptoms but may be at risk of more serious infections
Fever control with antipyretics may be necessary in some children
Empiric antibiotics may be needed in those at high risk of serious infection or who are clinically unwell, especially
shock

The end product
ded in those at high risk of serious infection or who are clinically unwell, especially
shock

The end product

				
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posted:10/10/2010
language:English
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