BACTERIAL ILLNESS IN CHILDREN Flashcards
What are the sites most commonly affected by staphylococcus aureus in children?
Skin - impetigo, boils
Wound infections - cellulitis
Bones - osteomyelitis
Joints - septic arthritis
Lungs - pneumonia
What are the two bacteria that are normally responsible for impetigo?
Staph aureus
Strep pyogenes
Where on the body does impetigo usually manifest?
Face - around the mouth
Creases - eg axilla
What are the risk factors for developing impetigo?
Anything that breaks the skin
Eczema
What are the clinical features of impetigo?
Erythematous macules
Golden “honey coloured” crusted lesions
Desquamation
What is the first line treatment for limited, localised impetigo in children?
Topical fusidic acid
What is the second line treatment for limited, localised impetigo in children?
Topical retapamulin
What is the treatment for limited, localised impetigo caused by MRSA?
Topical mupirocin
What is the first line treatment for extensive impetigo?
Oral flucloxacillin
What is the treatment for extensive impetigo in a child who is allergic to penicillin?
Oral erythromicin
What is an important source of reinfection that should be cleared in children with impetigo?
Nasal carriage
How is nasal carriage of staph aureus cleared in children who have had impetigo to avoid re-infection?
Nasal cream containing chlorhexidine and neomycin
What causes staphylococcal scalded skin syndrome?
Epidermolytic exotoxins A and B, which are released by S. aureus and cause detachment within the epidermal layer
What are the clinical features of staphylococcal scalded skin syndrome?
Fever
Widespread raw erythematous desquamation
Blistering, scalded appearance
Dehydration
How do we manage staphylococcal scalded skin syndrome?
Dermatological emergency
IV fluid resuscitation
IV flucloxacillin - If MRSA is suspected then use IV vancomycin
What are the infections that group A streptococcus (strep pyogenes) most commonly cause?
Pharyngitis / Tonsillitis
Cellulitis
Osteomyelitis
Septicaemia
Scarlet fever
Erysipelas
Toxic-shock like syndrome
How long is the incubation period of scarlet fever?
2 - 4 days
What is the peak age of incidence of scarlet fever?
4 years old (2 - 6 years)
What are the clinical features of scarlet fever?
Rash - fine punctate erythema (‘pinhead’), larger areas feel like sandpaper.
Desquamation happens later in disease.
Fever
Tonsillitis
Strawberry tongue
Where does the rash associated with scarlet fever usually appear?
Appears first on the torso and spares the face although children often have a flushed appearance with perioral pallor.
How is a diagnosis of scarlet fever made?
Throat swab
What antibiotics should be prescribed for someone presenting with the signs and symptoms of scarlet fever?
Oral Penicillin V
What antibiotics should be prescribed for someone with a penicillin allergy who presents with the signs and symptoms of scarlet fever?
Azithromycin
Other than antibiotics what other important step must the clinician take in the management of a patient with scarlet fever?
Scarlet fever is a notifiable disease
What are the complications of scarlet fever and how long after infection does each occur?
Otitis media: the most common complication, with or straight after infection
Rheumatic fever: typically occurs 20 days after infection
Acute glomerulonephritis: typically occurs 10 days after infection
Families from which endemic areas are most at risk of TB?
Indian subcontinent
Sub-Saharan Africa
How are children usually infected by Mycobacterium tuberculosis?
Inhalation of droplet nuclei from an adult
Children with the disease (even if active) are almost never infectious, therefore notification to public health is essential in contact tracing.
What are the classic features of active pulmonary TB in a child?
Chronic cough of more than 3 weeks - do not assume that this is asthma
Night sweats
Fatigue
Weight loss or failure to thrive
What are the rarer features of active pulmonary TB?
Bronchial obstruction by enlarged hilar lymph nodes
This might cause collapse and consolidation
Pleural effusions
Widespread lymphadenopathy
What age group are at a particularly high risk of disseminated disease eg TB meningitis?
Under 4 year olds
What are the main two tests used to assess exposure to TB?
Tuberculin test (Mantoux)
Interferon-gamma release assay
How is the Mantoux TB test performed?
0.1 ml of 1:1,000 purified protein derivative (PPD) injected intradermally
Result read 2-3 days later
How are the results of the Mantoux TB test read?
Size of lesion that develops:
Less than 6 mm - negative - may be given BCG vaccine
Between 6 - 15 mm - positive - but not confirmation. Cannot give BCG as may suggest previous exposure
More than 15 mm - strongly positive - highly suggestive of TB infection.
What could cause a false negative reading of the Mantoux TB test?
Miliary TB
Sarcoidosis
HIV
Lymphoma
Very young age (e.g.
How is the interferon gamma release assay TB test performed?
White cells from a blood sample are exposed to tuberculous antigens. If infection is present the white cells will secrete interferon-gamma.
When is the interferon gamma release assay TB performed?
For those in whom the Mantoux test gave an ambiguous reading or in those who have already had the BCG vaccine.
How do we culture M. tuberculosis in children?
Early morning gastric washing - sensitivity of 64%
Biopsy from lymph node
What are the radiographic features of TB in children?
Hilar lymphadenopathy - primary infection
Calcification point
Wedge of collapse - Consolidation
Cavitations
Millet sized granulomas
How do we treat TB in children?
Same as adults:
Rifampicin - 6 months
Isoniazid - 6 months
Pyrazinamide - 2 months
Ethambutol - 2 months
How does treatment for TB meningitis differ from pulmonary TB?
Treatment last for 12 months not 6
