Infectious diseases

Question 1

Transmission and presentation of chickenpox

Answer 1

Spread via respiratory route.
Caused by HSV 3
Infective for 4 days before rash appears to 5 days after rash appeared.

Presents with: Fever first, itch rash starting on head/trunk before spreading. Initially macular then papular then vesicular. Mild systemic upset.

Question 2

Management of chickenpox?

Answer 2

Keep child cool and trim nails, calamine lotion and school exclusion until all lesions are dry and crusted over (usually 5 days after rash appeared).
Immunocompromised patients and newborns with peripartum exposure should receive varicella zoster immunoglobulin. Consider IV aciclovir if chickenpox develops.

Question 3

Complications of chickenpox?

Answer 3

Secondary bacterial infection of lesion - Use of NSAIDs can increase this risk. Some patients may develop group A strep necrotizing fasciitis.

More rare - pneumonia, encephalitis, disseminated haemorrhagic chickenpox, arthritis, nephritis and pancreatitis.

Question 4

Features of Congenital Rubella?

Answer 4

• intrauterine growth restriction
• hepatosplenomegaly
• eye (glaucoma, cataract, retinopathy)
• congenital heart disease (pulmonary stenosis, patent ductus arteriosus)
• sensorineural hearing loss

Sensorineural deafness, cataracts, glaucoma and heart disease.

Question 5

Features of congenital toxoplasmosis?

Answer 5

Cerebral calcification, hydrocephalus and chorioretinitis.

Question 6

Features of congenital CMV?

Answer 6

Most common in UK. Presents with:
Low birth weight, purpuric skin lesions, deafness and microcephaly.
All congenital infections can cause cerebral palsy.

Question 7

Features of congenital vaaricella?

Answer 7

Cortical atrophy, microcephaly, limb hypodysplasia and skin scarring.

Hence why important infected mother get aciclovir.

Question 8

Clinical features of EBV?

Answer 8

Most children are asymptomatic with EBV.
Glandular fever triad is pharyngitis, fever and lymphadenopathy.
Other features = Palatal petechiae, anorexia, splenomegaly, hepatitis, atypical lymphocytes, haemolytic anaemia and maculopapular pruritic rash if given amoxicillin.

Question 9

Ix and Rx for EBV infection

Answer 9

Ix: heterophile antibodies.
Rx: Supportive care, avoid contact sport for 4 weeks, steroids if pharyngeal swelling compromises airway.

Question 10

Hepatitis A in Paeds

Answer 10

Transmitted via faecal oral route.
Children unlikely to be symptomatic but can present with fever, malaise, anorexia, abdo pain, D+V and cholestatic jaundice (usually 1 week after onset symptoms).
Ix: IgM anti HAV antibody and LFTs.
Rx: Supportive care

Question 11

Describe features of Scarlet fever

Answer 11

Occurs in children with Group A streptococcal pharyngitis.
Presents with tonsillitis, fever, strawberry tongue, palatal petechiae, widespread erythematous rash starting on trunk which desquamates on day 7-10.
Ix: clinical diagnosis but can be confirmed by Strep throat swab.
Rx: Penicillin or macrolide if pen allergic.

Question 12

What diseases do Group A strep cause?

Answer 12

Pharyngitis/tonsillitis,
Cellulitis,
Osteomyelitis,
Septicaemia,
Toxin mediated diseases - Scarlet fever, erysipelas, toxic shock syndrome.

Question 13

What is hand foot and mouth disease?

Answer 13

Self limiting viral illness caused by either Coxsackie A16 or enterovirus 71.

Question 14

What are the clinical features of Hand, foot and mouth disease?

Answer 14

Mild systemic upset: sore throat and fever.
Oral ulcers,
Vesicles on palms and soles of the feet.

Question 15

What is the management of Hand, foot and mouth disease?

Answer 15

Symptomatic treatment - hydration and analgesia.
Children do NOT need excluded from school

Question 16

What is Roseola infantum and its presentation?

Answer 16

Viral infection caused by human herpes virus 6 (sometimes 7).
Features - High fever followed by maculopapular rash, nagayama spots (papular enanthem on uvula), febrile convulsions, diarrhoea and cough.
Also risk of aseptic meningitis/hepatitis.
NO exlusion needed

Question 17

Features of HSV -1 in children

Answer 17

Primary HSV-1 normally asymptomatic but can present with gingivostomatitis, and high fever.
Less commonly presents with:
Eye: dendritic ulcers
Skin: eczema herpeticums.
Fingers: herpetic whitlow.
Brain: herpes simplex encephalitis.
Management - oral aciclovir is rarely helpful but IV can be used for herpes encephalitis

Question 18

Features of HSV 2

Answer 18

Transmission from genital tract of mother (whose often asymptomatic).
High mortality and morbidity.
Presents with generalised infection with pneumonia, hepatitis and encephalitis.
Treat with IV aciclovir and supportive care.
Prevention - C section in mother with active genital lesions

Question 19

Describe features/presentation of measles

Answer 19

RNA paramyxovirus - spread by areosols.
Presentation:
Prodrome - irritible, conjuntivitis and fever.
Koplik spots - occur before rash. Grain of salt like spots on buccal mucosa
Rash - starts behind ears then to whole body. Maculopapular rash which then desquamates

Question 20

Investigations and management for measles?

Answer 20

Ix: IgM antibodies
Rx: supportive care, admission if immunosuppressed and notify public health.

Question 21

Complications of measles?

Answer 21

Otitis media - most common.
Pneumonia,
Encephalitis,
Febrile convulsions
Keratoconjunctivitis,
Diarrhoea,
Appendicitis,
Myocarditis

Question 22

Features and presentation of mumps?

Answer 22

Infection with RNA paramyxovirus.
Presentation - fever, malaise and parotitis

Question 23

Management and complication of mumps?

Answer 23

Rx: Rest, paracetamol and notify public health.
Complications: orchitis, hearing loss (normally transient), meningoencephalitis and pancreatitis

Question 24

Describe features of erythema infectiosum?

Answer 24

Infection caused by parvovirus B19.
Presentation: fever followed by malar erythema rash one week later which progresses to symmetrical lacy rash on body.
Diagonosis - clinical but confirmation can be important so do IgM 2 weeks after exposure.

Question 25

Complications of erythema infectiosum/parvovirus B19.

Answer 25

Pancytopeniae in ummunocompromised.
Aplastic crisis in sickle-cell/hereditary spherocytosis.
Hydrops fetalis if mother becomes infected during pregnancy.

Question 26

Presentation of whooping cough?

Answer 26

Catarrhal phase - 1-2 weeks of URTI symptoms.
Paroxysmal phase - Cough becomes more severe, paroxysmal cough, post-tussive vomiting, spells of apnoea, inspiratory whoop.
Convalescent phase - cough subsides over weeks to months

Question 27

Diagnostic criteria for whooping cough

Answer 27

Cough that has lasted for 14+ days with one or more of following:
Paroxysmal cough.
Inspiratory whoop.
Post-tussive vomiting.
Undiagnosed apnoeic attacks in young infants.

Question 28

Diagnosis and management of whooping cough?

Answer 28

Diagnosis - nasal swab, PCR and serology (increasingly used)
Management - Admit infants under 6 months old. Notify public health. Give macrolide if onset cough within past 21 days. Exclude from school for 48hrs after starting abx or 21 days from onset of symptoms if no abx. Vaccinate women between 16-32 weeks

Question 29

Complications of whooping cough?

Answer 29

Subconjunctival haemorrhages, pneumonia, bronchiectasis and seizures.