Infectious Diseases Flashcards
What are important factors to consider in the presentation of a febrile child?
How has fever been identified e.g. electronic thermometer, tympanic
How old is the child
Any risk factors for infection e.g. illness in other family members, specific illness present in community, unimmunised, recent travel abroad
Contact with animals
Increased susceptibility from immunodeficiency e.g. post autosplenectomy in sickle cell, splenectomy, nephrotic syndrome - more at risk from encapsulated organisms e.g. strep pneumoniae, haemophilus
How ill is the child
Is there a rash
Is there a focus for infection
What are the red flag features suggesting urgent investigation in infection?
Fever >38 if <3 months
Fever > 39 if 3-6 months
Colour - pale, mottled, blue
Level of consciousness is reduced Neck stiffness Bulging fontanelle Status epilepticus Focal neurological signs or seizures Significant resp distress Bile stained vomiting Severe dehydration or shock
What is the management of the febrile child?
If significantly unwell, continue investigations, septic screen
Parental antibiotics given immediately, e.g. third generation cephalosporin e.g. ceftrixone or cefotaxime
Aciclovir if herpes simplex encephalitis suspected
What are some diagnostic clues to look out for when evaluating the febrile child?
URTI
Otitis media - examine tympanic membrane
Tonsilitis - any exudate or erythema on tonsils
Stridor - epiglottitis, croup, tracheitis
Pneumonia - fever, cough, raised RR, abnormal auscultation, CXR
Sepsis screen - tachycardia, tachypnoea, poor perfusion, start abx
Meningitis/encephalitis - lethargy, loss of interest, drowsy, seizure
In older children - headache, neck stiffness, photophobia, Kernig’s pain on straight leg
Abnormal posturing in raised ICP
Seizure - febrile convulsion, meningitis, encephalitis
Periorbital celllulitis - redness, swelling of eyes
Rash - viral exanthem, purpura from meningococcal
UTI
Abdominal pain - appendicitis, pyelonephritis, hepatitis
Diarrhoea - gastroenteritis
Blood in stool - shigella, salmonella, campylobacter
Prolonged fever Bacterial infection Kawasaki disease Drug reaction Malignant disease
What is the cause of bacterial meningitis?
Neisseria meningitidis
Strep pneumoniae
In neonates - Group B Strep GBS contracted during birth which live harmlessly in vagina
What is the presentation of meningitis?
Fever Neck stiffness Vomiting Headache Photophobia Altered consciousness Seizures
Meningococcal septicaemia presents with non blanching rash
Neonates - hypotonia, poor feeding, lethargy, hypothermia, bulging fontanelle
When is an LP in meningitis recommended?
Under 1 month with fever
1-3 months fever and unwell
<1 year with unexplained fever and other features of serious illness
What is Kernig’s test?
Lie patient on back, flex hip and knee to 90 then straighten leg with hip still flexed
Stretches meninges, causes pain or resistance
What is Brudzinski’s test?
Lie patient flat on back, use hands to lift head and neck off bed, flex chin to chest
Involuntary flexion of hips and knees if positive
What is the management of bacterial meningitis in the community?
In primary care and suspected and non blanching rash - urgent stat injection IM or IV of benzylpenicillin before transfer to hospital
In hospital - LP prior to starting antibiotics
Bloods for meningococcal PCR
<3 months cefotaxime plus amoxicillin (covers listeria contracted in pregnancy)
Above 3 months ceftriaxone
Vancomycin added if risk of penicillin resistant infection e.g. recent travel or prolonged antibiotic exposure
Steroids to reduce freq and severity of hearing loss and neuro damage
Dexomethasone 4x daily for 4 days to children over 3 months
Notifiable disease
What post exposure prophylaxis is required for meningococcal infections?
Single dose of ciprofloxacin ideally within 24 hours of the initial diagnosis
What are the most common causes of viral meningitis?
Herpes simplex
Enterovirus
Varicella zoster virus
Milder and needs supportive treatment
Aciclovir
What is seen on lumbar puncture in a bacterial infection?
Cloudy appearance
High protein and neutrophils
Bacterial culture present
Low glucose
Bacteria swimming in CSF will release protein and use up the glucose
Neutrophils released in response to bacterial infection
What is seen in CSF on lumbar puncture in a viral infection?
Clear appearance Mildly raised protein Lymphocytes released in viral infection so WCC high No culture Normal glucose
What are the complications of meningitis?
Hearing loss - inflammatory damage to cochlear hair cells
Local vasculitis may lead to cranial nerve palsies
Local cerebral infarction - focal or multifocal seizures, may lead to epilepsy
Subdural effusion may require more antibiotics
Hydrocephalus from impaired resorption of CSF or blockage
Cerebral abscess
What are the investigations for meningitis/encephalitis?
FBC Blood glucose Blood gas - acidosis Coag screen, CRP U&Es, LFTs Blood culture Sepsis 6 Rapid antigen test LP If TB suspected - CXR, mantoux, gastric washings or sputum early morning urines
Consider CT/MRI brain scan, EEG
What are the contraindications to lumbar puncture?
Cardiorespiratory instability
Focal neurological signs
Signs of raised ICP - coma, high BP, low HR, papilloedema
Coagulopathy
Thrombocytopenia
Local infection at sight
If it causes delay in starting antibiotics
What are causes of encephalitis?
Direct invasion of the cerebrum by neurotoxic virus e.g. HSV
Delayed brain swelling following disordered neuroimmunological response to antigen e.g. virus e.g. post infectious encephalopathy e.g. chickenpox
Slow virus infection e.g. HIV
What are the features of encephalitis?
Altered consciousness Altered cognition Unusual behaviour Acute onset of focal neurological symptoms Acute onset of focal seizures Fever
What are the investigations for encephalitis?
LP, CSF for viral PCR CT scan if LP contraindicated MRI EEC Swabs HIV Septic screen
What is the management of encephalitis?
Aciclovir for HSV and varicella zoster
Ganciclovir for cytomegalovirus
Repeat LP to ensure successful treatment before stopping antivirals
Aciclovir usually started empirically
What are the complications of encephalitis?
Lasting fatigue, prolonged recovery Change in personality or mood Changes to memory and cognition Learning disabilities Headaches Chronic pain Movement disorders Sensory disturbance Seizures Hormonal imbalance
What is seen in toxic shock syndrome?
Caused by toxin producing staphlococcus aureus and group A streptococci
Fever <39, hypotension, diffuse erythematous rash
Organ dysfunction
Mucositis: conjunctivae, oral or genital mucosa
GI: vomiting, diarrhoea
Renal and liver impairment
Clotting abnormalities and thrombocytopaenia
CNS - altered consciousness
What is the management of septic shock?
Intensive care support
Antibiotics - cephalosporin e.g. ceftriaxone with clindamycin
IV fluids to improve BP and tissue perfusion
What are the signs of sepsis in a child?
Deranged physical obs Prolonged cap refill Fever or hypothermia Deranged behaviour Poor feeding Inconsolable or high pitched crying High pitched or weak cry Reduced consciousness Reduced body tone - floppy Skin colour changes - cyanosis, mottled pale or ashen
Shock involves circulatory collapse and hypoperfusion of organs
What is the immediate management of sepsis?
Give oxygen if evidence of shock or sats below 94 Obtain IV access Blood tests - including FBC U&Es, CRP, clotting, blood gas, acidosis Blood cultures Urine dipstick Cultures and sensitivities Antibiotics given within 1 hr IV fluids
CXR if pneumonia suspected Abdo and pelvic USS LP Meningococcal PCR Serum cortisol if adrenal crisis suspected
Continue abx for 5-7 days
What is candida?
Yeast like fungus normal commensal in human GI tract and vagina
What are the risk factors for oral candidiasis?
Hot humid weather Too much time between diaper changes Poor hygiene Immunocompromise Antibiotics promote growth
What are the complications of candidiasis?
Oral candidiasis can cause chronic pain, discomfort
Impaired speech
Impaired eating, chewing, limits to nutrition
Candidemia - presence of species in the blood
What is the management of oral candidiasis?
Admit if evidence of systemic illness, widespread infection e.g. oesophageal candidiasis
Exclude risk factors e.g. diabetes, haematinic deficiences, poor dental hygiene
Prescribe miconazole oral gel first line if 4 months and over
Advise good dental hygiene
Rinse mouth after inhalation of inhaled corticosteroid
If after 7 days some response to tx, continue miconazole gel or offer 7 day course nystatin suspension
What is cutaneous candidiasis?
Nappy rash - contact dermatitis, moist warm environment in the nappy can lead to added infection with candida
Discrete red spots around the perineum, worse in skin creases
Send swab to microbiology
What is the management of cutaneous candidiasis?
Miconazole cream twice daily for 10 days
What is the presentation of cellulitis?
Erythematous, hot tender rash
May be associated with swelling and systemic features
What are some of the differentials for cellulitis?
Allergic/contact dermatitis
Impetigo - crusting lesions
Staph scalded skin syndrome
Necrotising fasciitis
What are the investigations for cellulitis?
Dental/max fax review if facial or submandibular
Send skin swab for MC&S if skin broken
Complex cellulitis - FBC, CRP, blood culture
What are the features of complex cellulitis?
Severe infection
Significant immunosuppression
Associated with VZV
Post-burn
What is the management of cellulitis?
If mild/mod treat with antibiotics e.g. flucloxacilllin or if penicillin allergy clarithromycin for 5-7 days
What is periorbital cellulitis?
Inflammation and infection of the eyelid soft tissue superior and anterior to the orbital septum.
What is orbital cellulitis?
Post-septal
Infection in the muscles and fat of the orbit so the septum can be affected and can lead to ocular dysfunction
What is the difference in periorbital and orbital cellulitis in children?
Children may develop it secondary to an occult underlying bacterial sinusitis or due to spread from another primary infection e.g. pneumonia
Means peri-orbital infection can progress rapidly to orbital cellulitis
What is seen on examination in peri-orbital cellulitis?
Redness and swelling
Can open eye sufficiently to demonstrate normal light reflexes and move in all planes
What are the red flags suspicious of orbital cellulitis?
Eyelid swelling that the eye is not visible Toxic/systemically unwell CNS signs or symptoms Severe persistent headache Pain on pressing closed eyelid Pain on eye movement Diplopia Reduced visual acuity Absent light reflexes No improvement on abx
What is the management of periorbital/orbital cellulitis?
Mild - oral abx; 5-7 days
co-amoxiclav
Orbital cellulitis
IV cefotaxime or oral amoxicillin 10-14 days
NBM if need for surgery, seek ENT and opthamology advice
CT scan orbit, sinuses, brain
FBC, blood culture, LP
What is conjunctivitis?
Inflammation of the conjunctiva of the eye
What are the types of newborn conjunctivitis?
Chemical - irritation from eye drops given at birth, lasts 2-4 days, does not need treatment
Gonococcal - from neisseria gonorrhoea, can be picked up from vaginal birth
Inclusion conjunctivitis - from chlamydia trachomatis - swollen red eyelids, fluid leaking from eyelids
What are the causes of childhood conjunctivitis?
Bacteria - staph aureus, strep pneumonia, chlamydia
Viruses - HSV, adenoviruses
Allergies
What are the symptoms of conjunctivitis?
Itchy irritated eyes Swelling of eyelids Redness of conjunctiva Mild pain looking at light Eyelids stuck together in the morning Clear thin fluid leaking from eyes; virus or allergens Crusty lesion - herpes infection
What is ophthalmia neonatorum?
Conjunctivitis of the newborn
Occurs within first month of life
Bacterial, chlamydial or viral acquired during passage through infected birth canal
Redness
Profuse discharge
Swelling of lids
Bilateral symptoms
Mucopurulent conjunctivitis
Oedema
Cornea can be involved, may cause perforation
What is the management of conjunctivitis?
First line - bath/clean eyelids with cotton wall in sterile saline or boiled then cooled water to remove crusting
Treat only if severe as most cases viral, self-limiting
Second line - chloramphenicol eye drops, azithromycin eye drops
Third line - fusidic acid
Herpes simplex - same day eye casualty, <1 month give IV aciclovir, >1 month give oral aciclovir
For ophthalmia neonatorum - cefotaxime single dose IV immediately, plus chloramphenicol eye drops
What is acute epiglottitis?
Life threatening emergency
Caused by H influenzae B.
Intense swelling of epiglottis and surrounding tissues associated with septicaemia
What are the clinical features of epiglottitis?
High fever, ill toxic looking child
Intensely painful throat, prevents child from speaking or swallowing
Saliva drools down chin
Soft inspiratory stridor
Rapidly increasing respiratory difficulty
Immobile, upright with open mouth to optimise airway
Onset over hours
No cough
Not able to drive
Reluctant to speak
What should not happen in epiglottitis?
Attempts to examine throat or perform lateral neck x-ray must not occur
Can precipitate total airway obstruction and death
What is the management of epiglottitis?
Urgent admission Senior anaesthetist, paediatrician, ENT Intubation Secure airway, blood cultures, start IV antibiotics Ceftriaxone Oral stepdown - co-amoxiclav
Prophylactic antibiotics rifampicin offered to close household contacts
What is scalded skin syndrome?
Exfoliative staphylococcal toxin which causes separation of the epidermal skin through the granular cell layers
Fever, malaise, purulent crusting localised infection around eyes nose mouth.
Areas of epidermis separate on gentle pressure.
IV antibiotics - flucloxacillin
Analgesia, monitoring fluid balance
What is the hallmark of herpesviruses?
After primary infection, latency is established
Long term persistence of virus within the host
After certain stimuli, reactivation of infection may occur
What is herpes simplex virus?
Enters body through mucus membranes or skin
Site of primary infection may be associated with intense local mucosal damage
HSV1 lip and skin lesions
HSV2 genital lesions
Treatment with aciclovir
What is gingivostomatitis?
Most common form of primary HSV in children
Vesicular lesions on lips, gums, anterior surfaces of tongue and hard palate.
Progress to extensive, painful ulceration and bleeding.
High fever, may persist up to 2 weeks.
Management symptomatic
Severe disease may need IV fluids and aciclovir
What are cold sores?
Recurrent HSV1 lesions on the gingival lip margin
What is eczema herpeticum?
Wide spread vesicular lesions develop on eczematous skin
May be complicated by secondary bacterial infection and result in sepsis
What are herpetic whitlows?
Painful erythematous oedematous white pustules on broken skin on fingers
Spread by auto-inoculation from gingivostomatitis and infected adults kissing children’s fingers
HSV2 may be cause in sexually active adolescents
What are the causes of a maculopapular rash?
Viral - roseola infantum Enteroviral rash Parvovirus slapped cheek Measles Rubella
Bacterial Scarlet fever - Group A strep Erythema marginatum - rheumatic fever Salmonella typhi Lyme disease
Other
Kawasaki disease
Juvenile idiopathic arthritis
What are the causes of vesicular bullous pustular rashes?
Viral
Chickenpox, shingles
Herpes simplex virus
Coxsackie - hand, footh, mouth
Bacterial Impetigo Boils Staphylococcal bullous impetigo Staphylococcal scalded skin Toxic epidermal necrolysis
Other
Erythema multiforme
Stevens-Johnson syndrome
What are the causes of a petechial purpuric rash?
Bacterial
Meningococcal, other bacterial sepsis
Infective endocarditis
Viral
Enterovirus
Other Henoch-Schonlein purpura Thrombocytopenia Vasculitis Malaria
What is influenza?
Respiratory infection caused by influenza virus
Spread because children touch noses, eyes, mouths, put things in mouth
Spread through droplets in the air, coughing, sneezing, touching surfaces
What are the features of flu in children?
Sudden fever, chills, shakes, headache, muscle aches
Extreme tiredness
Dry cough, sore throat
Loss of appetite
Newborns and infants with high fever that can’t be explained
Young children - temps over 39.5 and febrile seizures
Cause of croup, pneumonia, bronchiolitis
Stomach upset, vomiting, diarrhoea, abdominal pain, earaches, red eyes
