12.09.25 Ward round + teaching notes

Hemophagocytic lymphohistiocytosis (HLH)

• • 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

Epstein–Barr virus (EBV)

• • 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

Drugs and chemicals

• • 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)

Notes

• • 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