• Aggressive proliferation of activated macrophages and histiocytes, which phagocytose other cells, namely RBCs, WBCs, and platelets
• Commonly appears in infancy, although it has been seen in all age groups
• Features:
• Fever, hepatosplenomegaly, pancytopenia, lymphadenopathy, rash
• Cutaneous involvement occurs in as many as 65% of patients
• Subtypes:
• Primary hemophagocytic lymphohistiocytosis (ie, familial erythrophagocytic lymphohistiocytosis [FEL])
• Heterogeneous autosomal recessive disorder found to be more prevalent with parental consanguinity
  
• Secondary hemophagocytic lymphohistiocytosis (ie, acquired hemophagocytic lymphohistiocytosis)
  
• Occurs after strong immunologic activation, such as that which can occur with systemic infection, immunodeficiency, or underlying malignancy
• Both forms are characterized by the overwhelming activation of normal T lymphocytes and macrophages
• Invariably leads to clinical and haematologic alterations and death in the absence of treatment

Macrophage-activation syndrome (MAS)

• Similar + closely related to HLH
  
• Severe, potentially life-threatening, complication of several chronic rheumatic diseases of childhood
• Associations:
• Systemic-onset juvenile idiopathic arthritis (SoJIA)
• SLE
• Kawasaki disease
  
• Adult-onset Still's disease

• AKA human herpesvirus 4
• Half of all five-year-old children and 90 to 95 percent of adults have evidence of previous infection
• Causes few or no symptoms in children
• Causes infectious mononucleosis 35 to 50 percent of the time if infected for the first time during adolescence
• Infects B cells + epithelial cells
• => Permanent latency

Duplex kidney

• Duplicated kidney
• May have its own ureter
• Often associated with vesicoureteric reflux
• => Risk of pyelonephritis

Special feeds

• Peptisorb
• Nutritionally complete semi elemental tube feed
• For patients with impaired gastrointestinal function
• Neocate
• Nutritionally complete amino-acid based powdered infant formula, with long chain polyunsaturated fatty acids (LCP), DHA and ARA
• For the dietary management of infants with cow milk allergy

• VMA
• Vanillylmandelic acid
• End-stage metabolite of adrenaline + noradrenaline
  
• Check in pheochromocytoma, neuroblastoma etc
• Fluconazole
• Triazole antifungal drug used in the treatment and prevention of superficial and systemic fungal infections
• Amikacin 
• Aminoglycoside antibiotic
• Octreotide
• Somatostatin analogue
• Treatment of severe, refractory diarrhea (off-label)
• Flixotide = Fluticasone inhaler
• Montelukast
  
• Leukotriene receptor antagonist (LTRA)
• Atrovent: Ipratropium bromide
• Klean-Prep
• Macrogol 
• AKA polyethylene glycol
• => Osmotic diarrhoea
• Also sodium sulphate, sodium bicarbonate, sodium chloride and potassium chloride to replace those lost
• Used to empty bowel
  

Reticulocyte production index

• Start with the % of reticulocytes
• Correct for:
  
• Haematocrit (as in anaemia the proportion should be higher)
• Longer life span of immature reticulocytes
  
• Reticulocyte index (RI) should be between 1.0% and 2.0% for a healthy individual.
• RI < 1% with anemia indicates decreased production of reticulocytes and therefore red blood cells
• RI > 2% with anemia indicates loss of red blood cells (destruction, bleeding, etc.) leading to increased compensatory production of reticulocytes to replace the lost red blood cells

Water deprivation test

• Used to distinguish cause of polyuria / polydipsia
  
• Deprive of water:
• Primary polydipsia => Urine concentrated (fixed the problem)
• Diabetes insipidus => Urine still dilute
• Then can continue test, but add exogenous desmopressin (ADH):
• Central DI => Urine concentrated (fixed the problem)
• Nephrogenic DI => Urine still dilute (can't respond to ADH)
  

• POSCU
  
• Paediatric Oncology Shared Care Unit
• APML
• Acute promyelocytic leukaemia
• AML subtype
• FAB subtype M3
• Histiocyte
• Part of the mononuclear phagocyte system (also known as the reticuloendothelial system or lymphoreticular system)
• Histiocytes are:
• Tissue macrophages
  
• Dendritic cells
• Langerhans cells
• NCEPOD
• National Confidential Enquiry into Patient Outcome and Death
• Sarcomas arises from mesenchymal tissue
  
• i.e. Bone, cartilage, fat, muscle, vascular, hematopoietic
• Mesothelium
• Protective lining that covers many of the internal organs of the body
• Kidney scans:
  
• DMSA (Static)
• Most reliable test for the diagnosis of acute pyelonephritis
• Other indications:
• Renal scar, small or absent kidney, occult duplex system, renal masses, systemic hypertension or suspected vasculitis
• MAG3 (Dynamic)
• VIW: Viral induced wheeze
• MCUG test
  
• Micturating cystourethrogram
• To check for vesicoureteric reflux
• DIB: Difficulty in breathing
• Mastoiditis
• Inflammation of mastoid process
• Part of the temporal bone behind the ear
• Contains open air-containing spaces
• Can be caused by untreated otitis media
• Pinnaplasty
• Correction of prominent ears