Infectious disease Flashcards
What is Kawasaki disease
a systemic medium-sized vessel vasculitis
(aka mucocutaneous, lymph node syndrome)
Describe the epidemiology of kawasaki disease
- affects young children u5, peak incidence at 1yr
- mc in Japanese children
- mc in boys
Give 6 clinical features kawasaki disease
- Persistent high fever for over 5 days
- Non-purulent conjunctivitis
- Red (strawb) tongue and cracked lips
- Cervical lymphadenopathy
- widespread maculopapular rash
- Peeling of fingers and toes (later sign)
What is a major complication of kawasaki disease
coronary artery aneurysm
How is kawasaki disease investigated
- Clinical diagnosis
- ECHO - rule out aneurysms
How is kawasaki disease managed
- IV immunoglobulins - reduce risk of CA anueyrsms
- High dose aspirin
- ECHO at 6 weeks
Why is aspirin given to children with kawasaki disease
reduce the risk of thrombosis
What is the major route of HIV infection in children
mother-child (vertical) transmission during pregnancy (intrauterine), at delivery (intrapartum), or through breastfeeding
How is HIV diagnosed in children over 18 months
HIV antibody screen: detects antibodies against the virus
How is HIV diagnosed in children less than 18 months
HIV DNA PCR
Why is the presence of antibodies against HIV in children under 18 months not diagnostic of the illness
- Children <18 months who are born to
infected mothers will have transplacental maternal HIV antibodies - at this age a positive antibody test confirms HIV exposure but not HIV infection.
Presentation of children with mild and moderate immunocompromise in HIV
- Mild: may have lymphadenopathy or parotid enlargement
- Moderate: recurrent bacterial infections, chronic diarrhoea and lymphocytic interstitial pneumonitis
Clinical features of severe AIDS in children
- Pneumocystis jirovecii pneumonia
- severe faltering growth
- encephalopathy
How is HIV managed in children
- Antiretroviral therapy should be started in all infants and some older children depending on clinical status/ HIV load and CD4 count
- Don’t delay routine immunisations (except BCG)
- MDT and Regular follow up: weight, development and clinical signs of disease
- Prophylactic co-trimoxazole
Co-trimoxazole is given as a prophylaxis to some children with HIV.
a) what infection is this against
b) what circumstances is it prescribed (2)
a) pneumocystis jirovecii pneumonia
b) all infants who are HIV-infected and older children with low CD4 counts
Give 4 ways vertical transmission is reduced in HIV
- Positive mothers should be on antiretroviral drugs to reduce viral load at time of delivery
- Post exposure prophylaxis given to infant after birth (zidovudine)
- avoid breastfeeding
- C-sections in all women with > 400 copies / ml
- IV zidovudine should be given during the caesarean if the viral load is unknown or there are > 10000 copies / ml
What testing is done in children to HIV positive parents and at what age is each test done (2)
- HIV viral load at 3m - if -ve, child has not contracted HIV during birth and will not develop HIV unless they have further exposure
- HIV Abx test at 24m - to assess whether they have contracted HIV since their 3 month viral load, for example through breast feeding
What causes scalded skin syndrome
caused by a type of staphylococcus aureus bacteria that produces epidermolytic toxins
Describe the clinical presentation of scalded skin syndrome
- fever and malaise
- red rash with wrinkled tissue
- typically starts on face and flexural regions then spreads
- after the rash, large fluid-filled blisters form
- widespread erythema and tenderness
- Nikolsky sign
Describe Nikolsky sign
- The epidermis separates and creates an erosion when the skin is gently rubbed
- Large areas of skin blister and peel away, leaving red, wet, and painful areas
How is scalded skin syndrome managed
- IV anti-staph Ab e.g. flucloxacillin
- Analgesia
- monitor hydration and fluid balance
What causes toxic shock syndrome
Toxin-producing staph aureus and group A streptococci
Characteristics of toxic shock syndrome
- Fever over 39
- hypotension
- diffuse erythematous, macular rash
- desquamation of rash, especially of the palms and soles
Toxic shock syndrome causes organ dysfunction. Give 5 examples of this
- Mucositis - oral and genital mucosa
- GI dysfunction - vomiting/ diarrhoea
- Liver impairment
- renal impairment
- Clotting abnormalities and thrombocytopenia