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Hazelnut allergy

Allergy, General paediatrics

One of the tree nuts. One of the most common food allergens in the UK. Adults seem to get less severe reactions than children. Anaphylaxis rare compared with peanut and other tree nuts.

Hazel tree is related to birch, and indeed hazelnut allergy can be associated with tree pollen allergy (hay fever and pollen food syndrome), as well as fruit allergies.

Cor a 1 is the least likely to cause systemic reactions, and then only with raw cf roast.  But pretty much everyone tests positive for it, so not v helpful unless it is the only thing that is positive. You are usually also positive for rBet v 1/2, the birch pollen antigens.

Cor a 8/9/14 associated with systemic. Cor a 8 is LTP so likely fruit allergy too.

Cor a 9 and 14 (11s globulin and 2s albumin respectively, ie heat stable seed storage proteins) seem most useful  for defining kids at risk of systemic reactions – >1kU/l and/or >5 respectively give specificity of >90% and sensitivity of 83% in kids for “allergy with objective symptoms” viz more than just a tingle/itch, so more likely to have severe reactions. That translates to a negative predictive value of about 93% (PPV not given). [Dutch study, JACI 2013;132(2):393]

German study found  Cor a 14 had best AUC (0.89, cf 0.71 for whole hz).  Level of 0.35 gave 85% sensitivity with 81% specificity.  PPV doesn’t hit 90% until 47.8 though…

Chest X-ray

Clinical, General paediatrics, Respiratory

Interpretation

  • Start outside, work in – soft tissues, then bones, then lungs/heart, finally neck/infradiaphragmatic.
  • Safety check – position of lines/tunes, check apices for pneumothorax, any foreign bodies?

Adequacy

  • Rotation – look at symmetry of clavicles and anterior rib ends.
  • If clavicles high, then lordotic film. May obscure apices.
  • Penetration – should just be able to make out intravertebral spaces, without lung fields being too dark.
  • Inspiration – hila become artificially prominent if underinflated.

Thymus

Pesky thing! Can look like pneumonia. Latter more likely if air bronchograms, volume loss (displaced fissure/trachea/mediastinum), effusion. Classically:

  • indentations where ribs overlie.
  • Pointy outside edge (“sail sign”).
  • No mass effect
  • Lowish density – should still be able to see vascular markings of lung behind

Spinnaker sign is where pneumomediastinum around thymus creates long curving line.

Other normal things

Azygos lobe – normal variant where RUL has near vertical line curving up and out, from thick point (anomalous azygous vein) – giving impression of mediastinal mass.

Azygos love on chest x-ray
Azygos lobe at upper right

Mach effect – a line parallel to heart border, looks like pneumocardium but actually optical illusion where your eye “detects” border where there isn’t one…

One diaphragm usually higher than other – both ok, as long as no more than 2cm (one rib space).

Other

Hilum – rings or tram lines suggest bronchitis. Round opacity adjacent to and larger than ring suggests vascular prominence due to left to right shunt.

Silhouette sign – where heart border and/or diaphragm obscured in lower zone due to consolidation in lower lobe (left or right).

Effusion – vertical line at costophrenic angle.

Round pneumonia – will have air bronchograms, compare mass.

Collapse vs consolidation – sharp lower border is the fissure so if deviated then collapse.

Pneumothorax – lucency without clear edge may suggest lung hyperinflation eg bronchial atresia.

If edge projects below diaphragm then likely to be skin fold!

Foreign body – get expiratory film, which will enhance air trapping.

VATER/VACTERL

Congenital, Neonatology

VATER and VACTERL

Acronym for:

  • vertebral defects,
  • anal atresia,
  • tracheoesophageal fistula with
  • esophageal atresia [so should be VATOR in UK]
  • and radial dysplasia.

Nearly all cases sporadic, with no recognized teratogen or chromosomal abnormality. More common in infants of diabetic mothers.

VACTERL is the expanded syndrome, acronym for

  • vertebral anomalies, anal atresia,
  • cardiac malformations (Ventricular septal defects, Patent ductus arteriosus, Tetralogy of Fallot, Transposition of the great arteries),
  • tracheoesophageal fistula, esophageal atresia
  • renal anomalies (urethral atresia with hydronephrosis), and
  • limb anomalies (hexadactyly, humeral hypoplasia, radial aplasia, and proximally placed thumb).

Diagnosis made if 3 or more defects are present.

CHARGE sequence

Congenital, Neonatology

Stands for:

  • coloboma of the eye;
  • heart anomaly (Tetralogy of Fallot, ASD, DORV);
  • atresia choanae (failure of nasal passages to form – causes feeding difficulties);
  • retardation of mental and somatic development;
  • genital abnormalities eg microphallus (also hypogonadism, so delayed pubertal development in both sexes);
  • ear abnormalities and/or deafness.

Note that none of the letters used in the acronym are the same as used in VACTERL.

Facial palsy, cleft palate, and dysphagia are commonly associated.

The term CHARGE should be restricted to infants with multiple malformations and choanal atresia and/or coloboma, combined with other cardinal malformations (heart, ear, and genital), for a total of at least 3 cardinal malformations. Growth retardation is not one of the cardinal features.

Mostly isolated, mutation in CHD7 gene (associated with increasing paternal age).

Cobalamin related metabolic disorders

General paediatrics, Genetics, Haem/Oncology, Neurology, Renal

Amino acid homocysteine is converted to methionine (“remethylated”) – cobalamin is involved in some of these processes, folate metabolism also important.

Various disorders.

Variety of presentations, at different ages:

  • Neurological (central and peripheral)
    • Feeding difficulties, apnoea in babies
    • Seizures
    • Subacute combined degeneration of spinal cord (peripheral neuropathy, ataxia, incontinence)
    • Acute and/or chronic encephalopathy – hypotonia, regression
    • Neuropsychiatric problems
  • vascular problems (stroke/embolism)
  • bone marrow (megaloblastic anaemia, cytopenia) – folate related
  • Atypical HUS
  • Glomerulopathy

Investigations

  • High homocysteine, usually
  • Vitamin B12 and folate, for differential
  • Methylmalonic acid (in urine)
  • Acylcarnitine
  • Methionine (usually goes low)

Treatment

Start intramuscular B12 (hydroxocobalamin) as soon as samples collected, to prevent end organ damage.

Betaine should be started if high homocysteine with low methionine found, helps push conversion to methionine.

Homocystinuria

Autosomal recessive condition of high homocysteine in blood and urine, causing similar neurological problems, thrombosis, Marfanoid appearance, downward subluxing lenses.

Needs low methionine diet. Betaine supplements help.

Clinical teaching techniques

Generic, Teaching and training

Teachers generally believe they give regular and sufficient feedback, but this is often not how it is perceived by learners!

Set expectations – that most learning happens during daily patient care as part of the team. That teachers expect and welcome feedback themselves, and that feedback is normal everyday component of teacher-student relationship – else can generate defensiveness.

Feedback is a conversation about performance, rather than a 1 way lecture.

Modelling – think aloud, to externalize reasoning (in short spells!)

1-2 minutes direct observation.  Feedback perhaps after a number of episodes – one thing done well, one thing that could be done differently? Beware a list of demoralising fails. Avoid using the word “but” between the two, which seems to diminish the positive praise.

Balance feedback by asking for student’s own perceptions of their performance, and their ideas for improvement.

Send student ahead (“scouting“).

Self- explanation – without any instructions, student finds own explanations for results, obs, management plan etc.

SNAPPS – summarize case, narrow differential, analyse differential, probe [ask questions] where uncertain, plan, select an issue related to case for self directed learning.  1-2 mins only.

Tell me story backwards – Diagnosis, then supporting evidence, then why other diagnoses excluded.  Only then plan.

Contrastive example – ask student to give alternative diagnosis and balance probabilities.

Post it Pearls – record thoughts (not just pearls!) during clinic/ward round, review at end.

Diagnostic challenge – one person/team defends working diagnosis. Other asks about worse case scenario, or alternative diagnosis, investigations done or not done, and checks with patient themselves!

[Operation Colleague, from University of Glasgow; HPE Bytes]

GIRFEC

Community, Ethics, General paediatrics

Getting it right for every child. A framework for dealing with children and young people, looking at a range of values (SHANARRI).

Children and Young People (Scotland) Act 2014 made provision for Named Person and Child’s plan, but after review in 2019, amid privacy concerns (brought by Christian Institute, among others), government decided not to pursue legislation. Supreme court found that “duty to share information”, although well intentioned, was potentially at odds with article 8 of European convention on Human rights (“Privacy and family life”).

[https://www.gov.scot/publications/getting-right-child-practice-development-panel-report/]

Diet and mental health

General paediatrics, Mental health, Nutrition

Longitudinal research shows association between progressively higher glycaemic index diet and incidence of depressive symptoms. Experimental exposure to diets with high glycaemic load increases depressive symptoms in healthy volunteers, with moderately large effect.

Mechanism could be repeated and rapid changes in blood glucose, triggering counter regulatory hormones such as cortisol, adrenaline, growth hormone, glucagon.

Appears to be an inflammatory response to high glycaemic index foods too. Adherence to Mediterranean diet reduces markers. Mood disorders have been linked to heightened inflammation, although only in a minority. Observational studies show people with depression score higher for “dietary inflammation” viz trans fats, refined carbohydrates, lower intake of omega 3 fats. Mediated through polyphenols, polyunsaturated fatty acids?

Diet also affects microbiome, which interacts with the brain in bidirectional ways using neural, inflammatory and hormonal signalling pathways. High fibre, polyphenol, unsaturated fats promotes microbial taxa that generate anti-inflammatory metabolites such as short chain fatty acids.

Study of probiotics in healthy volunteers found altered response to a task that requires emotional attention, and may even reduce symptoms of depression.

But no benefit in large trial of Medierranean diet with subclinical depressive symptoms, only small trials of current depression showed benefit. Note context of people’s expectations regarding food/diet, which will likely have a marked effect on wellbeing.

Danger too of stigmatisation if trying to change an individual’s dietary choices.

[Joseph Firth, BMJ 2020;369:m2382]]

Remote consultations – use of images

Ethics

Clinical images are part of the medical record. Especially when they are being used to make clinical judgments, they should be retained, which means discussing transfer, storage and use of images.

Transfer – not subject to information governance and data protection rules until received! Whatsapp automatically uses end to end encryption.

Storage – needs to be deleted from your phone/device. NB Whatsapp has option to automatically save to phone. Arrange storage with NHS approved service, or else ask family to retain.

Use – needs specific consent to reproduce in any form, for specified purpose.

Document verbal consent.

If patients are unsure of sharing images, you could try sending illustrative images of the suspected condition.