Master CPS - Infectious Disease/Haematology
for MSRA

Core Concepts

Infectious Disease and Haematology commonly intertwine in paediatric presentations. High vigilance for sepsis is crucial in any febrile child, particularly neonates (<3 months) where atypical presentations are common. Always assess immunisation status. Haematological conditions often present with insidious symptoms like pallor, fatigue, bruising, or recurrent infections. Understanding age-specific norms and red flags is vital for MSRA.

Clinical Presentation

• Sepsis/Meningitis:
  • Non-specific (infants): Poor feeding, lethargy, irritability, grunting, mottled skin, decreased urine output, temperature instability (fever or hypothermia).
  • Specific (older children): Fever, altered mental status, neck stiffness, photophobia, headache, vomiting, non-blanching rash (petechial/purpuric), focal neurological signs, seizures. Bulging fontanelle in infants.
• Fever Without a Source (FWS) <3 Months: All febrile infants <3 months are high risk for serious bacterial infection (SBI) until proven otherwise.
• Iron Deficiency Anaemia (IDA): Pallor, fatigue, irritability, poor concentration, pica (craving non-food items), koilonychia (spoon nails), glossitis.
• Sickle Cell Disease (SCD):
  • Vaso-occlusive crisis: Severe pain (limbs, back, abdomen), dactylitis (painful swelling of hands/feet in infants).
  • Acute Chest Syndrome: Chest pain, fever, cough, dyspnoea.
  • Splenic Sequestration: Acute severe pallor, shock, rapidly enlarging spleen.
  • Increased infection risk: Especially encapsulated bacteria (e.g., Pneumococcus).
• Idiopathic Thrombocytopenic Purpura (ITP): Sudden onset petechiae, purpura, epistaxis, gingival bleeding, often preceded by viral illness. Otherwise well child.
• Acute Leukaemia (e.g., ALL): Insidious onset of pallor, fatigue, unexplained bruising/bleeding, recurrent infections (neutropenic fever), bone/joint pain (limp), lymphadenopathy, hepatosplenomegaly.
• Lymphadenopathy: Localised (viral/bacterial infection) vs. generalised (EBV, malignancy, autoimmune).

Diagnosis (Gold Standard)

Sepsis/Meningitis: Clinical assessment is paramount. FBC, CRP, procalcitonin, blood cultures, lactate, urine dipstick/culture. Lumbar puncture (LP) for suspected meningitis (after excluding raised ICP), HSV PCR (neonates). CXR if respiratory symptoms.
Anaemias: FBC (Hb, MCV, MCH). Serum ferritin (IDA - low). Hb electrophoresis (Sickle Cell, Thalassemia).
ITP: Diagnosis of exclusion. FBC (isolated thrombocytopenia, normal Hb/WBC), blood film. Coagulation screen typically normal.
Acute Leukaemia: FBC + blood film (blasts, abnormal counts), bone marrow aspirate and trephine biopsy (definitive), cytogenetics, immunophenotyping.
Lymphadenopathy: Clinical exam, USS, excisional biopsy if suspicious features.

Management (First Line)

Sepsis/Meningitis:

• ABCDE approach: Secure airway, support breathing (O2), circulatory support (IV fluids: 20ml/kg 0.9% NaCl bolus, repeat if needed; inotropes for refractory shock).
• Early broad-spectrum antibiotics: E.g., IV Cefotaxime/Ceftriaxone (add Vancomycin if resistant S. pneumoniae/meningitis suspected, Amoxicillin for Listeria in neonates).
• Dexamethasone: For bacterial meningitis (reduces neurological sequelae).

• Acute crisis: Hydration (IV fluids), analgesia (opioids), oxygen.
• Acute Chest Syndrome: Antibiotics, oxygen, often exchange transfusion.
• Long-term: Penicillin prophylaxis (until age 5), immunisations (pneumococcal, HiB, meningococcal), Hydroxycarbamide (reduces crises).

• Mild/moderate: Watch and wait, avoid contact sports/NSAIDs. Most resolve spontaneously.
• Severe bleeding/very low platelets: IV Immunoglobulin (IVIG) or corticosteroids.