eLetters

1577 e-Letters

  • The role and limitations of thyroid scintigraphy in identifying subtypes of congenital hypothyroidism

    Dear Editor,
    We read with interest the report by Worth and colleagues on thyroid scintigraphy in infants with congenital hypothyroidism (CH). While their study is valuable in confirming the role of scintigraphy in locating the gland, we are concerned at the assertion that a gland in situ (GIS) constitutes a “subtype” of CH, and their placing it alongside defined entities of permanent CH such as athyreosis and ectopia. GIS is a purely descriptive term, encompassing both permanent and transient CH and comprising hypoplasia (eg TSH-receptor and PAX8 gene mutations), thyroid enlargement (classical dyshormonogenesis, iodine insufficiency) and normal-sized thyroid (multiple aetiologies). Infants with GIS include preterm and sick babies who are likely to have transient CH. It is not clear how many of the 20/37 GIS infants with transient CH in Worth's study were preterm/sick or had Down syndrome, and their prevalence figures of 28% for ectopia and 26% for “dysplasia” would be higher if expressed in the context of permanent rather than transient CH.
    Worth et al have used scintigraphy to define GIS as small, normal and enlarged but do not state the criteria or detail their methodology. While scintigraphy reliably identifies thyroid ectopia, demonstrates intensity of isotope uptake and conveys an impression of gland size, ultrasound is superior in evaluation of size, vascularity (using colour Doppler) and detailed morphology2. Yet this modality is not discussed despi...

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  • Lucina, Community Water Fluoridation: New Zealand and American Academy of Guidelines

    Dear Editor

    We were delighted to see Lucina highlighted positive data on Community Water Fluoridation (CWF) [1] Has Luciana seen the latest American Academy of Paediatrics (AAP) guideline on the issue? [2] They state that the AAP Standard of Care is Fluoride Varnish. However we have asked them why CWF isn’t the standard of care given the only objection they give for it is that it is a “controversial and highly emotional issue”. In the same paper they make suggestions including that paediatricians should:

    1) Apply fluoride varnish
    2) Know how to determine the concentration of fluoride in a child’s primary drinking water and determine the need for systemic supplements.
    3) Advocate for water fluoridation in their local community.

    UK paediatricians cannot apply fluoride varnish. UK paediatricians can identify concentrations of fluoride in the local drinking water using www.onepartpermillion.co.uk. They can prescribe fluoride supplements where there is need.

    Until CWF is implemented does Lucina agree that these measures need promoting amongst UK Paediatricians?

    References

    1. Highlights from the literature Archives of Disease in Childhood 2020;105:1236.

    2. Clark MB, Slayton RL for American Academy of Pediatrics Section on Oral Health. Pediatrics 146 (6):e2020034637

  • Wilson disease: the affected newborn

    The disparity between estimates of the clinical and genetic prevalence of Wilson’s disease (WD) may be due to under-diagnosis or reduced penetrance of ATP7B mutations.
    The widely quoted disease prevalence of 1:30,000 from a 1984 paper is corroborated by a 4 recent studies giving estimates from 1:29,000 to 1:40,000 (1). By contrast the calculated frequency amongst 1000 UK control subjects of individuals predicted to carry two mutant pathogenic ATP7B alleles was 1:7026(2). Amongst 14,835 Korean neonatal dried blood spots it was 1:7561 (3).
    Assuming that under-diagnosis is not responsible these data suggest that penetrance in WD is approximately 20%. Interrogating the Genome Aggregation Database (gnomAD) revealed 231 WD-associated ATP7B variants giving an initial estimated population prevalence of around 1 in 2400. Using standardised genetic variant effect prediction algorithms WD-associated ATP7B variants with predicted low penetrance were excluded giving a revised disease estimate of around 1 in 20,000 and a penetrance of 12% (4).
    WD thus resembles alpha-1 antitrypsin deficiency (AAT); only ~10% PiZ individuals develop liver disease. So, what is the prognosis of the newborn found to have the same genotype as a sibling proband with AAT or WD and liver disease - the same risk as the general population or higher? In AAT, if the first PiZ child of PiZ heterozygote parents had unresolved liver disease, there was a 78% chance that a second PiZ child will h...

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  • Acute haemorrhagic oedema of infancy in neonates

    Acute haemorrhagic oedema of infancy, also termed cockade purpura with edema or Finkelstein-Seidlmayer disease, is a rather uncommon small-vessel leukocytoclastic vasculitis. It characteristically affects children 4 weeks to 23 months of age, is skin-limited, spontaneously recovers within 3 weeks, and does not recur. O'Connor C et al [1]. recently documented the distinctive features of acute haemorrhagic oedema in a 23-day-old male infant with fever, rhinorrhoea, conjunctivitis and cough. The authors concluded that acute haemorrhagic oedema has never previously been reported in neonates, with the exception of a female newborn infant noted to have this vasculitis at birth [2].
    Stimulated by the fascinating report by O'Connor C et al. [1], we analyzed the data contained in the Acute Hemorrhagic Edema BIbliographic Database AHEBID, which includes all articles on acute haemorrhagic oedema. In the mentioned database, we found 6 further cases (4 males and 2 female patient) of this vasculitis in subjects less than 4 weeks of age, including 4 familial cases [3-5].
    It is therefore concluded that acute haemorrhagic oedema has been so far documented in a total of 8 patients (5 males and 3 female patient) less less than 4 weeks of age. In this age group, this vasculitis is uncommon but not exceptional and may affect 2 or more members of the same family.

    References
    1. O’Connor C, Bux D, O’Connell M. Acute haemorrhagic oedema of infancy: first report...

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  • The newborn with 2 WD mutations

    The disparity between estimates of the clinical and genetic prevalence of Wilson’s disease (WD) may be due to under-diagnosis or reduced penetrance of ATP7B mutations.
    The widely quoted disease prevalence of 1:30,000 from a 1984 paper is corroborated by 4 recent studies giving estimates from 1:29,000 to 1:40,000 (1). By contrast the calculated frequency amongst 1000 UK control subjects of individuals predicted to carry two mutant pathogenic ATP7B alleles was 1:7026(2). Amongst 14,835 Korean neonatal dried blood spots it was 1:7561 (3).
    Assuming that under-diagnosis is not responsible these data suggest that penetrance in WD is approximately 20%. Interrogating the Genome Aggregation Database (gnomAD) revealed 231 WD-associated ATP7B variants giving an initial estimated population prevalence of around 1 in 2400. Using standardised genetic variant effect prediction algorithms WD-associated ATP7B variants with predicted low penetrance were excluded giving a revised disease estimate of around 1 in 20,000 and a penetrance of 12% (4).
    WD thus resembles alpha-1 antitrypsin deficiency (AAT); only ~10% PiZ individuals develop liver disease. So, what is the prognosis of the newborn found to have the same genotype as a sibling proband with AAT or WD and liver disease - the same risk as the general population or higher? In AAT, if the first PiZ child of PiZ heterozygote parents had unresolved liver disease, there was a 78% chance that a second PiZ child will hav...

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  • Oximetry-detected pulsus paradoxus predicts for severity in paediatric asthma

    We read with interest the paper by Krishnan et al.1 and agree that "pulsus paradoxus" (PP) of the oximetry plethysmogram (pleth) may be useful in assessing severity of acute asthma exacerbations in children. The visual assessment they propose is one of a number of approaches which have been used, with variable success in predicting clinical outcomes2,3,4.

    Rather than pulse amplitude variation associated with respiration, figure 2 in the paper1 shows predominately baseline undulation, at a rate of about 1/5 to 1/6 of pulse rate; no time base nor simultaneous respiratory waveform is included. Can the authors thus be sure that the variation is due to respiration, and if it is, could the baseline variations in fact be associated with respiratory-related changes in peripheral blood volume? As the visual pleth display is dependent on processing by the pulse oximeter, it would be helpful to know more about the oximeter used.

    We have monitored respiration using Respiratory Inductance Plethysmography (RIP) bands simultaneously with oximetry pleth in children with acute wheezing illness using a SOMNOscreen plus recorder (SOMNOmedics GmbH, Germany) with Nonin oximeter module (Nonin Medical Inc., USA). We developed software in MATLAB (The MathWorks Inc., USA) for quantifying pleth pulse amplitude to assess pulsus paradoxus analogous variation. Consistent with Krishnan et al., we found that chil...

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  • Normal infant sleep behaviours

    Dear Editor,

    We note with interest the conclusions made in the longitudinal cohort review published by Cook et al1 linking frequent night wakings in infancy with emotional disorders in later childhood. Our analysis of the paper questions whether the medical profession is overmedicalising normal sleep behaviours without fully identifying what is within normal limits.

    Multiple potential confounders were not adjusted for in the analysis, including but not limited to: method of feeding, neonatal and infant medical history, sleep environment (co-sleeping and bedsharing) or the proportion of parents implementing sleep training methods. Additionally, statistical significance for these conclusions was reached by comparing the babies labelled with with ‘persistent severe sleep problems’ (19.4%) with those classed as ‘settled sleepers’ (23.7%), rather than the 56.0% of babies labelled with ‘moderate sleep problems’. Over half of the cohort were repeatedly waking at night, confirming that this is a common feature of normal infant behaviour. This paper provides a much-needed opportunity to discuss our social expectations of infant sleeping patterns and the increasing risk of overmedicalising normal sleep behaviours.

    Modern western culture necessitates that adults sleep at night in order to function at work during the day. Societal changes over the last century have normalised the idea that babies too should sleep through the night, and this has slipped into the id...

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  • Functional abdominal pain: what clinicians need to know

    Re Functional Abdominal Pain: what clinicians need to know

    In their article on the above subject, Andrews et al rightly emphasise that the majority of cases of recurrent abdominal pain in childhood are “functional” ie not associated with structural organic disease.
    In placing this large number of potentially differing problems under one large umbrella I feel the authors are ignoring important subdivisions, each requiring a different approach. In particular, they only mention abdominal migraine twice in the whole article, and then only in passing.
    The work of the late George Russell put abdominal migraine firmly on the map of UK paediatrics but it seems his message has been lost (1). With a prevalence of 4.1% of the population it seems likely that abdominal migraine is the commonest cause of children presenting with recurrent abdominal pain.
    Rather than being a diagnosis of exclusion, abdominal migraine can be regarded as a positive clinical diagnosis based on a clear history. In typical cases the pain is clearly episodic and can come on in any situation. The pain is diffuse and central, and there is associated nausea and even vomiting, often associated with facial pallor and dark rings under the eyes. There is often a past history of travel sickness and usually a positive family history of migraine.
    Parents seem to find being given a positive label and an explanation that makes sense to be maximally reassuring. Reassurance and explanation alo...

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  • Improving outcomes for children with asthma: role of national audit

    Dear Editor

    In their report “Improving outcomes for children with asthma: role of national audit”(1), Sinha et al highlight the fact that the UK has one of the highest mortality figures from childhood asthma for high-income countries worldwide. They detect complacency regarding childhood asthma, and call for a targeted proactive model to improve matters.
    The possible explanation for their observations regarding clinic attendance may be relevant to these wider issues.
    The most likely explanation is that parents had not been given adequate safety netting advice regarding how to recognise and treat acute attacks. Such safety netting should have included parent- initiated steroids. Had this safety netting been in place, each of the cases reported would have already been started on oral steroids.
    Another possibility is that the parents had not even been told that their child had asthma, or that asthma can kill. Many units seem to make children “earn” a diagnosis of asthma, after several years of being labelled “Viral associated wheeze”.

    In my experience working as a locum around the UK, most units stop short of permitting parent- initiated steroids. Parents are simply told to use up to 10 puffs of a beta agonist and if this doesn’t work to “Seek medical advice”. However, this policy fails to recognise that severe attacks can occur in situations where medical help is not close at hand, for instance on holidays in remote places or abroad. Surely we...

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  • Functional Abdominal Pain

    I read with interest the review on functional abdominal pain and link to anxiety. However, there is no mention of the potential aetiology for anxiety.
    In our school age paediatric neurodevelopmental clinic , children and young people with diagnoses of Autism Spectrum Disorder often present with escalating levels of anxiety in relation to school attendance that is reflected in a range of physical symptoms that may include abdominal pain, headaches and sleep disturbance . Indeed ,they have often been under the care of the acute paediatric service and prescribed a variety of medications. School attendance has often been affected and/or there have been concerns about learning and behaviour leading to referral to the Neurodevelopmental /Community Paediatric clinic
    Once reasonable adjustments and environmental modifications have been implemented to support the individual , anxiety diminishes and physical symptoms improve. This has been most noticeable during the recent lockdown with many young people with ASD flourishing without the incapacitating anxiety that is associated with the busy, complex, social environment of school.
    A detailed psycho - social and neurodevelopmental history and consideration of the possibility of Autism Spectrum Disorder is likely to be helpful for this group of children and young people.

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