Infectious Diseases Flashcards
What is Kawasaki disease and who does it affect?
Systemic vasculitic disease which affects children aged 6mo - 4y, peaking at 1yo. Particularly Japanese and black/AC ethnicity
unknown aetiology, may have inflammation of BCG scar
How would a child with Kawasaki present?
remember CRASH + Burn:
- Conjunctivitis
- Rash (polymorphous, beginning on hands and feet)
- Adenopathy (cervical, usually unilateral)
- Strawberry tongue
- Hands and feet are red, swollen and peel/desquamate
- Burn - fever OVER 5 days and unresponsive to anti-pyretics
How would you manage (Ix+Mx) a child with potential Kawasaki disease? What is a complication of Kawasaki’s?
Ix:
- clinical diagnosis (no test)
- bloods (FBC, CRP, ESR)
- ECHO! (due to increased risk of coronary artery aneurysms)
Mx:
- Admission
- High dose aspirin to reduce thrombosis risk + IVIG (within 10 days)
- other agents include CS, infliximab/ciclosporin and plasmapheresis for persistent inflammation and fever
note: children with coronary artery aneurysms may require long-term warfarin and close follow up
What causes a mumps infection? What is the incubation and infective period?
Mumps paramyxovirus [viral]
- transmitted via respiratory secretions
- long incubation period (15-24 days)
- infective 5 days before and 5 days after parotid swelling (should pass totally after 1-2 weeks)
How may a child with mumps present?
Sx:
- 30% cases asymptomatic
- headache, fever
- PAROTID swelling!!
- other complications include pancreatitis, neuritis, pericarditis etc
How would you investigate and manage a child with mumps? What are some complications to be wary of?
Ix:
- Oral fluid IgM sample
- Bloods - inc amylase levels which will be raised
Mx:
- notify HPU and isolate for 5 days from time of parotid swelling
- supportive Tx (fluids, analgesia, rest) and advice to parents
- safety net for complications - deafness (usually transient, unilateral), viral meningitis/encephalitis (rare) and orchitis (infertility - rare)
How is measles transmitted + its incubation? When is the infective period?
Paramyxovirus, spread through respiratory droplets
- one of the most communicable diseases (>15 mins is enough contact)
- incubation = 7-18 days, infective period = 4 days before and 4 days after rash
How may a child with measles present?
Sx:
- prodromal symptoms = high fever, coryza/conjunctivitis, irritability, febrile seizures
- maculopapular rash (from face/neck to hands and feet)
- Koplik spots (white spots in mouth)
- cough
- NO LYMPHADENOPATHY
How would you Ix + Mx a patient with measles? What are complications to be wary of?
Ix:
- ELISA IgM and IgG bloods
- Oral fluid test of measles IgM and IgG
- PCR of blood or saliva (2nd line)
Mx:
- Notify HPU and isolate for 4 days following rash development
- Rest and supportive treatment, good fluid intake
- Immunise close contacts and encourage vaccination after acute episode
- Vitamin A orally
- Safety net complications:
- -> Seek help if getting worse, DiB
- -> Otitis media (most common)
- -> Pneumonia (most common cause of death)
- -> Encephalitis (headaches, lethargy, irritability–>seizures), –>SSPE (7y later - measles dormant in CNS causing dementia and death)
- -> Keratoconjunctivitis
What is rubella infection caused by? What is the infective period?
Rubella, AKA German measles, is caused by a togavirus infection via respiratory droplets (coughing and sneezing) - similar to measles
- incubation = 6-21 days
- infective 1 week before to 5 days after rash onset
How may a child present with rubella?
Sx:
- Prodrome = mild fever/asymptomatic
- PINK maculopapular rash (face –> whole body) and fades in 3-5 days
- 20% get Forchheimer spots (red spots on soft palate)
- lymphadenopathy (suboccipital, postauricular)
How would you investigate and manage a child with rubella? What is a complication of rubella?
Ix:
- Oral fluid test for rubella serology (IgM and IgG)
- (2nd line) reverse transcriptase PCR
- FBC
Mx:
- Notify HPU and isolate for 4/5 days after rash onset
- supportive tx
- safety net (haemorrhage complications due to thrombocytopenia)
What is slapped cheek/fifth disease and which cells do they infect? How is it transmitted and how long are pt’s infective?
Parvovirus B19 infection - respiratory droplet transmission + vertical transmission
- infects RBC precursors in the bone marrow
- infective 10 days before to 1 day after rash onset
How may a child with PB19 present? What about i) in utero ii) in SCD and immunodeficient children?
Sx:
1st - asymptomatic OR coryzal illness for 2-3 days
then latent for 7-10 days
2nd - erythema infectiosum which starts with red slapped cheek rash on face (+fever, malaise, headache, myalgia)
—> progresses 1w later to maculopapular ‘LACE’-like rash on trunk and limbs
- Can cause aplastic crises in children with SCD or immunodeficiency
- fetal disease via maternal transmission can cause fetal hydrops, death due to severe anaemia
How would you manage (Ix+Mx) a child with PB19?
Ix:
- Clinical Dx
- Oral fluid test for B19 serology (IgG, IgM)
- RT-PCR (2nd line)
Mx:
- Supportive Tx (will clear in ~3 weeks)
- no need to stay off school as after rash onset they are not really infectious
- safety net (anaemia, lethargy, pregnancy)
What is chicken pox caused by and what is its infective period? How is it transmitted?
Varizella Zoster virus (VZV/HHV-3) - reactivation of dormant infection can lead to herpes zoster (Shingles)
- direct contact/inhalation/respiratory transmission
- incubation - 10-21 days
- infective - 48h before rash to until the last lesion is crusted over (~5-7 days post-onset of rash)
How would a child with VZV present?
Sx:
- fever, headache, abdominal pain and malaise
- crops of ITCHY vesicles appear over 3-5 days (head, neck and trunk»_space;»> than limbs)
- papule –> vesicle –> crust
How would you manage (Ix+Mx) a child with VZV? What are some complications/reasons for admission?
Ix:
- Clinical Dx
Mx:
- Supportive (fluids, rest, analgesia but NO ibuprofen –> can cause nec.fasc. and complications)
- Advice (infective until last lesion crusted, trim nails, keep cool, calamine lotion)
- Isolate from school and also immunocompromised, pregnant women and neonates (<28d old)
Special cases:
- Admission if serious complications such as:
- -> Bacterial superinfection (sudden HIGH fever –> toxic shock, necrotising fasciitis)
- -> Encephalitis (ataxic with cerebellar signs)
- -> Purpura fulminans (large necrosis of skin due to cross-activation of antiviral abs)
- -> Severe dehydration
Medical:
- -> Immunocompetent adolescents/adults - oral acyclovir 800mg 5/day for 7 days if within 24h of rash onset
- -> Immunocompromised children (IV > oral acyclovir); prophylaxis IVIg also available
What is hand, foot and mouth disease and how may it present? Who is often affected?
Most commonly due to Cocksackie A16 virus (severe may be enterovirus 71 and atypical may be Cocksackie A6)
Common in children <10, very contagious
Sx:
- Mild systemic features (fever, sore throat, spots in mouth that develop –> ulcers)
- Painful, itchy, vesicular lesions on hands, feet, mouth and buttocks
How would you manage a child with hand, foot and mouth disease?
Clinical Dx
Mx:
- Supportive (rest, fluids, analgesia)
- Advice - will clear in 7-10 days (HPA don’t say you NEED to be kept from school but recommended to stay away until feel better)
- Safety net: dehydration, if it doesn’t clear within 2 weeks, pregnancy
What is Roseola Infantum?
AKA Sixth disease; caused by HHV6
- most children infected by age 2 (6mo-2y) - younger than other infections
- highly infectious + infective during whole period of disease
How would a child with roseola infantum present?
Sx:
- HIGH fever (>40) and malaise (3-4d) –> generalised macular rash of small pink spots which are non-itchy and blanching (neck/body –> arms) - appears as fever wanes
- many have fever + no rash and so can often be confused with measles/rubella
- febrile convulsions in 10-15%
- coryza symptoms, sore throat, lymphadenopathy, D&V
- Nagayama spots (on uvula and soft palate)
How would you manage (Ix+Mx) a child with roseola?
Ix:
- HHV6/7 serology (IgG,IgM). and also for measles/rubella
Mx:
- supportive (will clear in 1w)
- no need to stay off school
- safety net - high fever can lead to febrile convulsions,
What happens in children born to a HIV+ mother?
<18mo - PCR of virus measured at birth, discharge, 6w, 12w and 18mo (still have maternal transplacental anti-HIV IgG)
>18mo - antibody detection (ELISA)
Management:
- Cord clamped ASAP and baby bathed immediately after birth
- Zidovudine mono therapy for 2-4w (low/medium risk) or PEP combination (2 NRTIs + INI - high risk)
- Mothers NOT to breastfeed
- All immunisations given including BCG [unless moderate/high risk of transmission]
- Infant testing for HIV at 6 and 12 weeks (at least 2 and 8 weeks after stopping prophylaxis)
How would congenital rubella syndrome present?
Eyes - congenital cataracts, other eye issues Ears - sensorineural deafness Brain - CNS defects Cardiac - PDA, heart defects Jaundice, hepatosplenomegaly etc
Timing of infection affects outcome i.e. T1 = high risk CRS (90%, 20% miscarry); T3 = low risk
When and how would T-cell immunodeficiency present? What are some causes?
Di George Wiskott-Aldrich syndrome Duncan disease SCID HIV Ataxia telangiectesia
Presents <1yo with severe viral or fungal infections
When and how would B-cell immunodeficiency present? What are some causes?
Brutons (XLHG)
HyperIgM syndrome
Common variable ID
Selective IgA def
Presents >6m but <2yo with severe bacterial infections
How would neutrophil immunodeficiency present? What are some causes?
CGD
Presents with recurrent bacterial infections or invasive fungal infections
How would NK immunodeficiency present? What are some causes?
Recurrent viral infections
- Classical NK deficiency
- Function NK deficiency
How would leukocyte function defect immunodeficiency present? What are some causes?
LAD
Sx = delayed separation of umbilical cord and chronic skin ulcers
How would complement immunodeficiency present? What are some causes?
Recurrent bacterial infections, especially encapsulate bacteria (NHS)
- Early complement deficiency (C1,2+4)
- Late complement deficiency (C5-9)
