Category Archives: General paediatrics

Pyrexia of Unknown Origin

Clinical, General paediatrics, Immunology, Infectious disease

A technical term, not just a fever without obvious source! Essentially presence of confirmed fever for 8 days or more in a child in whom a careful thorough history and physical examination, and preliminary laboratory data fail to reveal a probable cause.

Long list of possible causes, long lists of possible tests – do thorough history and repeated examinations, then follow the clues!

In kids, infection is the commonest cause. But can be connective tissue disorder, or malignancy.

Beware factitious fever – admission sensible.

If possible, stop all drugs. Antipyretics may obscure the pattern of fever, and can occasionally be its cause (drug fever is one cause).

Unless the child is critically ill, try not to give antibiotics. If the diagnosis remains obscure, go back and take the history again, examine the child (fully) again, send the specimens again!

Special points in history/examination

  • Travel – malaria can present 6-12 months later. Typhoid.
  • Ethnicity – tuberculosis
  • Outdoor activities – rats/ticks as vectors of infectious diseases
  • Animal contact – cows/sheep (brucellosis), cats (cat scratch)
  • Mouth ulcers (IBD, Behcets, PFAPA)
  • Periodicity – see Periodic fever
  • Sinus tenderness, nasal congestion (sinusitis)
  • Bone/spine tenderness – discitis, vertebral osteomyelitis

Tests

  • 3 sets of blood cultures, different sites, different times (at least a few hours apart), off antibiotics – standard for endocarditis
  • ASOT
  • EBV, CMV
  • LDH, CK
  • ANA/RF
  • Urine/stool culture
  • Swab everything!

Stroke in children

Emergency medicine, General paediatrics, Neurology

Rare but happens.

Differential:

Can be due to arterial or venous occlusion.  50:50 in kids cf adults (80% infarct). Haemorrhagic can be due to rupture into infarct.

Presents with focal signs, headache, seizures most commonly. Else dysphasia, vomiting!, confusion. Fever! Acute signs often lacking or fluctuant cf history!  FAST criteria only 78% sensitive. 

NIH stroke severity scale has paeds version. 

Risk factors

Black/Asian

Cardiac (esp surgery, right to left shunt)

Sickle cell – esp anaemia, acute chest syndrome, HbS or HbS/Beta thal

Thrombophilia

Liver/kidney disease (secondary prothrombotic tendency)

VZV within 1yr, enteroviruses, HIV.

Vasculitis – Moya Moya (peaks at 5-9yr else adulthood), SLE, other

Cocaine, glue.

Marfans, homocysteinuria, Fabry’s disease, Neurofibromatosis

Cancer, radiotherapy

Hypoglycaemia. 

Management

High flow O2, 10ml/kg saline 

Imaging within 1hr. 

BP – avoid high and low? Cf adults

Monitor for RICP

Treat with aspirin.

Tests

  • CTA/MRA at time of CT/MRI
  • Echo
  • (Transcranial doppler in sickle cell- via temporal bony window)
  • Hbopathy screen
  • Cholesterol
  • Lupus anticoagulant, Anti cardiolipin ab (ACLA), consider beta 2GP1
  • Homocysteine
  • Alpha galactosidase
  • Lipoprotein A – marker for CVS disease, genetic. 
[RCPCH guideline May 2017]

Allergy testing

Allergy, General paediatrics

Gold standard is double blind challenge, but who has time for that?

Mostly based on history – combination of characteristic features without other, more likely, explanation.

NICE has list of type 1 vs non type 1 allergy signs/symptoms – some overlap, eg vomiting, diarrhoea, itch.

EAACI guidance 2023 says where type 1 allergy suspected (signs/symptoms but also timing and consistency of reaction):

  • Do skin prick testing and/or specific IgE testing as first line
  • For peanut, hazelnut or cashew, if in doubt do component tests Ara h 2, Cor a 14, Ana o 3 respectively as well (if available) – otherwise do skin prick or IgE if not done already.
  • Where peanut or sesame allergy still in doubt, do basophil activation test (BAT – if available)
  • “Reassessment of food allergic children, at regular intervals, depending on age, food and patient’s history, is suggested for possible development of spontaneous tolerance”

Ara h 2 (cut off 0.44) has 82% sensitivity and 92% specificity cf 84 and 86% for SPT of 4mm. Cor a 14 (cut off 0.64%) has 73 and 95%, Ana o 3 (cut off 0.4) 96 and 94%.

Common hidden allergens (!): celery, mustard, cochineal, lupin, soy, fenugreek, other legumes such as pea/bean/lentil protein, insects/mealworm, pink peppercorns).

Bartter’s syndrome

General paediatrics, Genetics, Renal

Abnormal renal excretion, leading to low potassium.

Presents in early childhood with failure to thrive. Could also be constipation, muscle cramps and weakness (potassium needed for membrane potential, so these are all neuromuscular) and non-specific dizziness and fatigue.

Characteristic hypokalemic, hypochloremic metabolic alkalosis. High plasma renin activity and high aldosterone concentration seen.

Gitelman syndrome is similar, less severe (distal tubule, rather than ascending limb of loop of Henle) – less failure to thrive, in fact often asymptomatic detected incidentally. Might present with nocturia/polyuria.

Urinary calcium excretion distinguishes the two syndromes. Bartter’s waste calcium (more severe, after all), Gitelman retain.

Treatment is with supplementation.

Decompensation can be precipitated by diarrhoea or vomiting. Acute treatment can include potassium-sparing diuretics (spironolactone), cyclo-oxygenase inhibitors and renin-angiotensin blockers.

Pseudo-Bartter’s is due to CF.

Hypokalaemia

Clinical, General paediatrics, Neurology, Renal

Could be reduced intake but usually excessive losses –

RenalNon-renal
Renal tubular acidosis (type 1 or 2)Vomiting eg pyloric stenosis
Bartters or Gitelmans syndromeDiarrhoea
DiureticsLaxative overuse
Hyperaldosteronism (CAH, tumour)Thyrotoxicosis
Salbutamol
Familial periodic paralysis
Pseudo-Bartter’s
Trauma
Diabetic ketoacidosis

Symptoms depend on severity and how rapidly decrease has happened. Chronic low levels are better tolerated. Since potassium important for membrane potentials, effects are mostly neuromuscular.

  • Cramps, weakness, paralysis
  • Ileus
  • Metabolic acidosis (although underlying cause often produces alkalosis)
  • Arrhythmia, heart failure
  • Rhabdomyolysis

ECG classically shows U waves, T wave flattening, and ST-segment changes. Can be tall wide P waves, can look like long QT if T and U waves merge.

Do urine and blood electrolytes to look at fractional excretion.

[Endocrine connections 2018][Current Treatment Options in Peds 2022]

Fragile X

Community, General paediatrics, Genetics

Cause of developmental delay.

FMR1 gene is on X chromosome, obviously, and is a trinucleotide repeat disorder (along with Friedrich’s ataxia, myotonic dystrophy, Huntington disease etc), so inheritance is interesting.

Dads can carry gene, but only pass it on to their daughters (who will all get it).

Mums will carry gene on 1 chromosome, so sons and daughters can both get it, but 50:50 chance.

As with other trinucleotide repeat disorders, gene expands with each generation, so risk of disease increases from 1 generation to the next, and this is somewhat predictable: intermediate gene (so 45-54 copies) won’t expand to cause disease (200+ copies) in 1 generation, but premutation gene (55-199) copies probably will.

Features:

  • Moderately severe learning disability
  • Facial features – long face, midface hypoplasia, large lips and jaw, small ears
  • Macro-orchidism

Females less severely affected, of course.

Neuroblastoma

General paediatrics, Haem/Oncology

Neural crest tumours – cells that migrate to form sympathetic chain, including adrenal glands. 

Usually young children, usually already metastases at presentation – that’s because mostly vague symptoms until an abdominal mass or lymphadenopathy obvious.

Several eye related symptoms possible –

  • Dancing eyes (opsoclonus-myoclonus) a famous association – only seen in 1% of neuroblastoma but 1/3 of opsoclonus-myclonus syndrome (includes ataxia too!) have it.
  • Horner’s syndrome associated, as sympathetics (dilated pupil) run with oculomotor nerve.
  • “Panda eyes” are a rare clinical finding – proptosis, bruising – from orbital mets. 

Catecholamines are a marker but only rarely do you get symptoms eg hypertension, sweating, diarrhoea. 

Bone pain and fever are not uncommon. Otherwise depends were the mass effects are eg obstructive jaundice, dysphagia.

Investigations

GD-2 marker. Catecholamines as above.

MRI full body else MIBG scintigraphy. 

“Metastatic special” risk category – under 18 months, only skin, liver, marrow. Resolve spontaneously even when extensive!

Screening programmes in Germany and US doubled pick up rate but no change in mortality… Probably because detected more of these Metastatic special cases.

Arrhythmia

Cardiology, Emergency medicine, General paediatrics

See SVT.

Adenosine 150mcg/kg? 12yr 3mg

Broad complex SVT – just treat as VT.

Cardioversion

Remove oxygen tubing for shocks unless closed circuit.

Stand clear – look at top/middle/bottom!

IM/IN ketamine plus sedation for synchronised shock.

Synchronised shocks are 1 then 2 J/kg.

Sync button needs pressed for each shock – most machines immediately reset. Press and hold – needs time to sync and give shock.

Resuscitation

Emergency medicine, General paediatrics

UK Resuscitation council updates guidelines from time to time.

See also anaphylaxis (now 2 guidelines, basic and refractory) and arrhythmia.

Atropine not part of guideline – neonates 10mcg/kg (no minimum). Else 20mcg/kg min 100mcg. 

Out of hospital – Shout for help AND ask for an AED.  Sudden OOH collapse likely to be cardiac, even in a child – don’t wait till after rescuer breaths!

Compressions 100-120.min for both infants and children. One third depth of chest – 4cm infant, 5 child (6 adult). 1 finger breadth above xiphisternum to avoid organs. 

40% blood volume might be lost before hypotension appears…

5th centile for systolic BP is 70 at 1yr, 80 at 10, 90 at 15yr. 

Haemothorax might be picked up in B but don’t manage until C!

C – compartments of body incl long bones. 1:1 RCC:FFP

TXA – bolus, remember 2nd dose (or double bolus). 

Log roll can be missed if suspected spinal unless penetrating back wound suspected (or found on absorbent surface…)

ATMIST – age, time, 

Parents need a senior person who understands!

CT head might be better done at trauma centre…