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