Paeds Infectious Diseases Flashcards
Causes of Scarlett Fever
Most common in children 2-6 peak at 4Y
- Spread by resp droplets
- Toxins produced by Group A strep
Signs & Symptoms Scarlett fever
- Fever 24-48h
- Malaise, headache, vomitting
- Strawberry tongue
- punctate erythema rash on torso
- Pallor with flushed appearance
- sandpaper texture rash
no conjunctivitis so different to kawasaki
Investigations & Management Scarlett Fever
- throat swab
- Oral Penicillin for 10 days
- Notifiable disease
- Can return to school after 24h of Abx commencement
Complications Scarlett Fever
- Otitis media: the most common complication
- Rheumatic fever: typically occurs 20 days after infection
- Acute glomerulonephritis: typically occurs 10 days after infection
- Invasive complications (e.g. bacteraemia, meningitis, necrotizing fasciitis) are rare but may present acutely with life-threatening illness
Kawasaki Disease Pathophysiology
boys are more affected than girls; peak age at 1. Most common cause of acquired heart disease in children in the UK.
- type of vasculitis which is predominately seen in children
Kawasaki Disease Signs and Symptoms
- high-grade fever which lasts for > 5 days. Fever is characteristically resistant to antipyretics
- conjunctival infection (bilateral)
- bright red, cracked lips
- strawberry tongue
- cervical lymphadenopathy
- red palms of the hands and the soles of the feet which later peel
- erythematous maculopapular rash and desquamation (skin peeling) on the palms and soles.
Complications: coronary artery aneurysm
Children are often irritable and miserable, and have a high fever that is difficult to control
Kawasaki Disease Investigations & Management
No specific diagnostic test
IgG may be raised for certain infxns
- high-dose aspirin
- IV immunoglobulin
- ECHO for coronary artery aneurysm detection
PIMS: add corticosteroid too
Kawasaki disease is one of the few indications for the use of aspirin in children. Due to the risk of Reye’s syndrome aspirin is normally contraindicated in children
Measles Pathophysiology
RNA paramyxovirus
outbreeaks occur due to insufficient vaccine uptake in some parts of the world.
Virus is an RNA virus that is transmitted via droplets and infects the epithelial cells of the nose and conjunctiva. Primary viraemia occurs 2-3 days after infection, and virus continues to replicate over next few days.
Infective 4 days before to 4 days after onset of rash.
Typically occur in preschool and young children with peak incidence in the late winter or spring
Measles Signs And Symptoms
3 phases
- prodromal phase
* irritable
* conjunctivitis
* fever - Koplik spots
* typically develop before the rash
* white spots (‘grain of salt’) on the buccal mucosa - rash
* starts behind ears then to the whole body
* discrete maculopapular rash becoming blotchy & confluent
* desquamation that typically spares the palms and soles may occur after a week
diarrhoea occurs in around 10% of patients
COMPLICATIONS
Encephalitis occurs in 1 in 5000 cases, a few days after the onset of illness. Mortality is 15% - serious long-term sequelae include seizures, deafness, hemiplegia and severe learning difficulties.
Subacute sclerosing panencephalitis (SSPE) is a rare but devastating illness manifesting 7 years after infection on average in about 1 in 100,000 cases. Caused by measles virus variant which persists in the CNS.
Can also lead to acute otitis media (around 10% of cases) and lower respiratory tract infxn, Febrile convulsions, pneumonia (most common cause of death)
Measles Investigations and Management
Investigations IgM antibodies can be detected within a few days of rash onset
- mainly supportive
- admission may be considered in immunosuppressed or pregnant patients
- notifiable disease → inform public health
if a child not immunized against measles comes into contact with measles then MMR should be offered (vaccine-induced measles antibody develops more rapidly than that following natural infection) within 72h
lifelong immunity
Chicken Pox (varicella zoster) Pathophysiology
Primary varicella zoster infxns
- Highly contagious infection that is spread through direct contact with the lesions or through infected droplets from a cough or sneeze
- 10d -3wks incubation
- Infectious period begins 2 days before vesicles appear
- no longer infectious after crusted leisons
Chicken Pox Signs and Symptoms
- Fever initially
- widespread rash – erythematous, raised, vesicular, blistering lesions.
- Usually starts on the trunk or face and spreads outwards affecting the whole body over 2-5 days.
- Lesions progress through stages: papule, vesicle, pustule, crusting.
- May also have headache, anorexia, signs of upper respiratory tract infection, fever and itching
recover after 2wks
Chicken Pox Management & Investigations
- Usually self-limiting with symptomatic treatment of fever and itching.
- Children should be kept off school. until leisons are crusted
- Immunocompromised children should be treated with intravenous aciclovir initially
Complications
* 2ndry bacterial ifxn: due to group A strep - toxic shock syndrome NSAIDS Increase risk
* Encephalitis
* Pnuemonitis
* Cerebro stroke
* Shingles (rare in childhood)
Rubella
AKA german measels
Infxn with togavirus - rare now due to vaccinations
- the incubation period is 14-21 days
- low grade fever, maculopapular rash on face before spreading to whole body 5 days
- lymphadenopathy: suboccipital and postaurricular
- Tx: Supportive MMR Vaccine as supportive.
Complications are rare in childhood but may develop arthritis, myocarditis, encephalitis or thrombocytopenia.
- Can severely damage fetus of a preganant woman: deafness, cataracts, heart disease, learning disability
- in first 8-10 weeks risk of damage to fetus is as high as 90%, rarely any damage after 16wks
- suspected cases of rubella in pregnancy should be discussed with the local Health Protection Unit
. Most cases are now generally in those unvaccinated
Diphtheria signs & Symptoms
Gram positive bacterium Corynebacterium diphtheriae
releases an exotoxin encoded by a β-prophage inhibiting protein synthesis. Causes a diphtheric membane on tonsils caused by necrotic mucosal cells.
- Respiratory diphtheria: sore throat, low-grade fever, dry cough and an adherent pseudomembrane covering tonsils and the mucosa of the pharynx, larynx and the nose. eyes, ears, or genitals may be affected. Grey, pseudomembrane on the posterior pharyngeal wall
- Cutaneous diphtheria is usually a mild disease causing cutaneous sores or shallow ulcers.
can lead to heart block or neuritis
Recent travel to EE, Russsia or Asia is RF
Diphtheria Investigations & Management
Investigations
culture of throat swab: uses tellurite agar or Loeffler’s media
Management
intramuscular penicillin
diphtheria antitoxin
Diphtheria is now included in the UK vaccination programme, with doses given at:
- 2 months – 6-in-1 vaccine
- 3 months – 6-in-1 vaccine
- 4 months – 6-in-1 vaccine
- 3 year, 4 months – 4-in-1 vaccine
- 14 years – diphtheria, tetanus, polio vaccine
U5’s
Staphylococcal Scalded Skin Syndrome
Epidermolytic Toxic Release from Staph Auerus
- Toxins break down Proteins in skin (proteases) which hold skin together. Damages skin. Adults develped immunity to these toxins
- Fever, Malaise, Purulunt, crusting infxn of eyes. Separation of epidermis and formation of blisters which burst and give sore skin
- Untreated can lead to sepsis& prone to dehydration
- IV Abx (flucloxacillin) 500mg/QDS
- Electrolyte balance important
Need to rule out burns as can look very similar.
infants under 6 months with suspect pertussis should be admitted
Pertussis ( whooping Cough)
Gram -ve Bordetella Pertusis
Women who are between 16-32 weeks pregnant will be offered the vaccine.
- 2-3 days of Coryza then coughing bouts leading to vomit
- Inspiratory whoop
- Spells of Apnoea
- Cough can last 14 days
- PCR for B.pertusis
- Notifiable disease
- Oral Carithromyosin, erythromyocin.
- household contacts should be offered antibiotic prophylaxis
antibiotic therapy has not been shown to alter the course of the illness - Child can return to school 48hr after commencing Abx or 21 days after infection of no Abx
infants are routinely immunised at 2, 3, 4 months and 3-5 years. Newborn infants are particularly vulnerable, which is why the vaccination campaign for pregnant women was introduced
- Infection or Vaccination does not guarantee lifelong protection.
Faeco-Oral transmission
poliomyelitis AKA Polio
Caused by Poliovirus
Characterised by muscle weakness and permanent paralysis.
- Muscle Weakness, Permanent paralysis in some cases (unilateral, proximal limbs, legs over arms). Alot of aymptomatic cases or fever, aches non specific symptoms in some cases.
- Minor illeness: D&V, sore throat
- PCR for detection
- No treatment, in rich countries: inactivated poliovirus vaccine
- Oral to GI Tract where it invades CNS - destruction of motor neurone
often becomes latent inchildhood
Tuberculosis in Childhood
Infection with mycobacterium tuberculosis
Spread by droplet, bacilli remain at entry site and some travel to lymph nodes. Bacilli multiply at both sites. spread then via blood and lymphatics. Infection at this point may become dormant
As immune system responds to spreading infection (3-6 weeks later) systemic symptoms develop:
- Fever
- Anorexia and weight loss
- Cough
Reactivation may present as localised disease or may be widely disseminated (miliary TB) to sites such as bones, joints, kidneys, pericardium and CNS. Children particularly prone to tuberculous meningitis.
* Mantoux test - tuberculin skin test.
* Inteferon Gamma release essays
Complications: Pneumothroax or pleural effusions
Management RIPE for two months (3mths if Millary)
Rifampicin
Isoniazid
Pyrazinamide
Ethambutol
After Two months
- Decreased to just isoniazid and rifampicin for a further 4 months.
Major routes of transmission are mother-to-child,
HIV in Children
Clinical presentation varies with the degree of immunocompromise. Those with mild degree may only have lymphadenopathy or parotid enlargement; if moderate there may be recurrent bacterial infections, candidiasis, chronic diarrhoea and lymphocytic interstitial pneumonitis.
Severe degree = lots of pportunistic infections
- In children over 18 months, HIV infection diagnosed by detecting antibodies against the virus.
- Preferred starting therapy is two nucleoside/nucleotide reverse transcriptase inhibitors plus one of a ritonavir-boosted protease inhibitor, a non-nucleoside transcriptase inhibitor or an integrase inhibitor. Goal to suppress viral load to undetectable. Majority of infected children survive to adulthood with effective treatment.
MENINGOCOCCAL DISEASE
by Neisseria meningitidis, colonising the nasopharynx
Meningococcal meningitis is when the bacteria is infecting the meninges and the cerebrospinal fluid around the brain and spinal cord.
Bacterial infection of the meninges usually follows septicaemia but can be isolated.
- fever, neck stiffness, vomiting, headache, photophobia, altered consciousness and seizures.
- Infants often do not have classical symptoms and therefore there is lower threshold for suspicion.
- Can also present with non-blanching rash
- Brudzinski sign positive in meningitis – flexion of neck with child supine causes flexion of knees and hips
- Kernig positive – flexion of hips and knees in supine child causes pain in back on knee extension
- Lumbar puncture performed with suspected meningitis (all children under 3 months with a fever should have this) unless there is suspicion of raised ICP, will delay antibiotics or is contraindicated for another reason.
Commuity: IM Benzylpenicillin
Hospital: IV Ceftriaxone + amoxicillin (cover for listeria)
Dexamathesone also given
Encephalitis
may occur in those who are not vaccinated: polio mumps rubella & measles
- most common virus being herpes simplex virus.
- Inflammation of the brain parenchyma (meninges may also be affected).
- with fever, altered consciousness and often seizures.
- LP with Viral PCR
- Antiviral treatment: Accyclovir in HSV or VZV
- Ganivlovir in CMV
5th disease
Erythema Infectiosum AKA Slapped cheek
Infection with human parvovirus B19 (HPV-B19).
Transmission is via respiratory secretions, vertical transmission from mother to fetus or transfusion of infected blood products
- mild fever, noticeable rash which looks like slapped cheek
- rose red rash, may spread to rest of body minus soles & palms
- Can cause acute arthritis
- Virus can affect new born baby in childhood (first 20wks of pregnancy) - hydrops fetalis
sunlight or heat can trigger recurrence of symotoms
Parovirus can also
* cause aplastic crisis in sickle cell,
* hydrops fetalis: severe anaemia due to viral suppression of fetal erythropoiesis → heart failure secondary to severe anaemia → the accumulation of fluid in fetal serous cavities (e.g. ascites, pleural and pericardial effusions)
* Treated with Intruterine blood transfusions.
yelolow crusts aound lips
Impetigo
Localised, highly contagious skin infxn caused by staphys or strep
Nasal carriage is often the source of infection.
Impetigo can be classed as non-bullous (Nose and mouth) or bullous impetigo caused by staphy also has golden crust
- Impetigo occurs when bacteria enter via a break in the skin;
- Clin diagnosis - Bacterial culture of exudate
- Hydrogen perozide 1% cream
- Topical Abx (fusidic acid)
Extensive disease
* oral flucloxacillin
* oral erythromycin if penicillin-allergic
children should be excluded from school until the lesions are crusted and healed or 48 hours after commencing antibiotic treatment
multiorgan involvement
Staphylococcal toxic shock syndrome
Staphylococcal toxic shock syndrome describes a severe systemic reaction to staphylococcal exotoxins,
- fever: temperature > 38.9ºC
- hypotension: systolic blood pressure < 90 mmHg
- diffuse erythematous rash
- desquamation of rash, especially of the palms and soles
- involvement of three or more organ systems: e.g. gastrointestinal (diarrhoea and vomiting), mucous membrane erythema, renal failure, hepatitis, thrombocytopenia, CNS involvement (e.g. confusion)
Management
* removal of infection focus (e.g. retained tampon)
* IV fluids
* IV antibiotics
common in u10
Hand Foot & Mouth
Coxsackie A virus
Virus is spread via direct contact with throat discharges, saliva, vesicle fluid or faecal material from an infected person.
- Typical URTI
- 1-2 days later small mouth ulcers appear followed by blistering red spots on hands feet and mouth
- supportive care; hydration and analgesia
- ## Children do not need to be excluded
common in u10
Hand Foot & Mouth
Coxsackie A virus
Virus is spread via direct contact with throat discharges, saliva, vesicle fluid or faecal material from an infected person.
- Typical URTI
- 1-2 days later small mouth ulcers appear followed by blistering red spots on hands feet and mouth
- supportive care; hydration and analgesia
- ## Children do not need to be excluded
Mumps features
RNA paramyxovirus
Complications
* orchitis - uncommon in pre-pubertal males but occurs in around 25-35% of post-pubertal males. Typically occurs four or five days after the start of parotitis
* hearing loss - usually unilateral and transient
* meningoencephalitis
* pancreatitis
- fever
- malaise, muscular pain
- parotitis (‘earache’, ‘pain on eating’): unilateral initially then becomes bilateral in 70%
- rest
- paracetamol for high fever/discomfort
- notifiable disease
