Asthma and Obesity

Obesity can mimic asthma, it affects respiratory symptoms and lung mechanics, but it can also overlap of course. Asthma is more often diagnosed in obese (misdiagnosed?). High birth weight is associated. , as is maternal obesity (and gestational weight gain) in pregnancy. Each BMI increase of 1kg/m2 increases risk by 2-3%!

Obesity is one of the factors associated with fatal asthma attacks (but note socioeconomic confounding).

Weight reduction leads to improved lung function, health status, symptoms and morbidity in adults. Not yet proven in adolescents.

Slightly increased risk of acute asthma attacks in obese adults and school age children.

Multiple Sclerosis in children

Only 3-5% of cases of MS have symptoms before the age of 16. Most have a relapsing-remitting course, particularly in the beginning, typically with one to two relapses per year. The frequency of attacks does seem to predict disease severity and earlier evolution to secondary progressive phase.

Although it takes longer in kids to develop persistent disability, they still develop it at a relatively young age, for example the third or fourth decade of life. That is of course going to have significant effects on life course, including work and family life.

Even at onset, cognitive function is often reduced, which will also affect education and socialisation. So clearly there is interest in disease modifying treatments.

Presentation in younger children often follows an infectious illness. Cognitive impairment is more common relative to older kids.

Investigations

MRI of brain and spine, looking for demyelinating lesions.

Monoclonal bands in CSF.

Treatment

Steroids 10-30mg/kg for 3-5 days effective. No good evidence for IVIG. Where acute life threatening symptoms, plasmapheresis may be effective where steroids fail.

In adults good evidence for interferon Beta in relapsing-remitting disease, IM or SC depending on product, reduces relapse rate and probably slows progression of disability. Glatiramer is a synthetic product with similar effects.

Second line treatments in adults include Natalizumab, mitoxantrone and cyclophosphamide.

Osteogenesis imperfecta

Recurrent fractures, often with minimal trauma, family history. Joint and bone pain can be an issue even without fractures.

No single test for osteogenesis imperfecta.  Clues might be deformities, short stature, hypermobility and poor dentition.

Type 1 is most mild, no deformities. Type 2 lethal in early life, antenatal scan may show chest wall abnormality and respiratory failure often at birth.

Type 3 is severe, with fractures in the womb or during birth. Short stature, deformities marked.

Type 4 variable, may only be diagnosed later in life. Type 5 associated with excessive callus formation.

Bisphosphonate infusions are used for the most severely affected. Otherwise, management revolves around:

  • Fracture and pain management
  • Aids eg wheelchairs
  • Physiotherapy, esp if immobile due to fractures

Epstein Barr virus

One of the Herpes virus family, and so becomes incorporated into human lymphocytes after infection. Immune system has developed specific strategies over the course of human evolution to control it – hence specific immunodeficiencies such as Duncan’s syndrome where EBV appears to be the only infection that becomes problematic (even catastrophic).

Associated with a number of tumours, including non-Hodgkin’s lymphoma, Burkitt Lymphoma.

In most children, a mild febrile illness, with lymphadenopathy (“glandular fever”), sore throat (can be severe). Failure to improve with antibiotics! Peak age for severe presentations is teenagers – “kissing disease” (sexually transmitted!? Edinburgh students study found lower rates if routine barrier methods used). Prolonged incubation period of 30-50 days!

Classically rash triggered by amoxicillin (which is why amoxicillin isn’t recommended for sore throats, but rash seen with penicillin too) – maculopapular, sometimes petechial and/or urticarial, which is rather more suggestive.

On examination, hepatosplenomegaly can be seen.

Blood film characteristically shows atypical lymphocytosis. Monospot test has false negatives and positives so may need to proceed to PCR if important to know.

Mild hepatitis pretty common.

Management

Supportive.

Splenic rupture after EBV has been reported but is very rare. Advice usually given to avoid contact sports. In ultrasound studies, peak spleen size is typically noted within the first 2 weeks of illness, but may extend to 3.5 weeks. The majority of spleen injuries occur within the first 21 days of illness and are exceedingly rare at >28 days, so one month avoidance probably sufficient.

A minority develop chronic fatigue type symptoms.

[Sports health 2014]

Anaemia

Like many things, low red cell count can be problem of production, loss or destruction.

So causes include:

  • Bone marrow failure or infiltration (leukaemia, Fanconi’s, Blackfan Diamond, erythrovirus/parvovirus)
  • Nose bleeds, gastrointestinal losses eg Meckel’s, gastritis, heavy periods
  • Haemolysis eg G6PD deficiency, hypersplenism, autoimmune
  • Iron, folate or B12 deficiency

In children, one of the most common causes is excessive milk consumption, which appears to lead to a low level colitis. Pica is often the presenting problem.

Investigations

  • Blood film – Howell Jolly bodies if hypersplenism. Leucoerythroblastic reaction (with immature red cells, as well as immature white cells) can be due to malignancy but can also be due to infection and haemolysis. Spherocytes or other abnormal forms may suggest a hereditary haemolytic condition. Sickle cells in sickle cell disease.
  • Low MCV suggests lack of iron, but may also be due to thalassaemia.
  • Reticulocyte count – indicates on going red cell production, may be high if recovering from low production
  • White cell count and platelets – if low too, suggests bone marrow failure but parvovirus can knock off all cell lines too.
  • Coagulation – deranged coagulation with low platelets suggests disseminated intravascular coagulation (DIC), usually due to sepsis, but can also reflect haemophagocytosis syndrome (due to sepsis or rheumatological disease)
  • Renal function – haemolytic uraemic syndrome (usually with diarrhoea and bloody stools, but not always)

Iron is found in red meat, pulses, green leafy vegetables, wholemeal bread, nuts, dried fruit, fortified breakfast cereals.

Polycythaemia

Polycythemia vera very rare in kids but described from age 7 months! More typically age 5-14yrs. 

Haemoglobin range of 15.5 to over 25, with haematocrits from 41-80%.  Yet high values often seen in asymptomatic teenagers.

Symptoms are headaches, pruritus, dizziness/syncope.  Serious complications not uncommon, often part of presentation eg Budd-Chiari syndrome, stroke, haemorrhage.  Leukocytosis appears to be associated with higher risk of complications.   Thrombocytosis often seen. 

Molecular studies available. [Ann Hem 2009 PMID PMID: 19468728]

Hypertension

In children under 10, high BP is usually secondary to an underlying disease or condition. Primary hypertension increasingly recognised in older, obese children.

Do repeated measurements, ideally automated home BP monitoring, before diagnosing hypertension. Check manually as well as with automated device. Beware “white coat effect”, even if not clearly anxious.

Use appropriate cuff size – cuff should cover at least 75% of the upper arm from the acromion to the olecranon (should be sufficient space at the antecubital fossa to apply stethoscope!) .  An inappropriately small cuff will overestimate BP.

Long list of causes, so follow the clues.

Family history important, of course.

Examination

So needs thorough history and examination, including:

  • Fundi
  • Bruits, radiofemoral delay
  • Neck for goitre

Complications

Consider then end organ effects –

  • Proteinuria, high creatinine
  • Retinopathy
  • Left ventricular hypertrophy, cardiac failure
  • Abnormal tone and reflexes, cranial nerve deficits if severe

Management

Depends on how high, whether other risk factors (diabetes, chronic kidney disease), symptoms and evidence of end organ damage.

Initially low salt diet, weight loss (if obese).  Remember other morbidities related to obesity.

Acute hypertension might need frusomide and/or nifedipine.

Long term treatment is only going to be started if no improvement with lifestyle measures. Target BP depends on risk factors, as above.

[2016 European Society for Hypertension guidelines]

Meningococcal disease

Gram negative diplococci, causing meningitis and septicaemia. Sometimes bone/joint infection. Neisseria (not meningitidis) responsible for ophthalmia neonatorum.

Main serogroups:

  • A – responsible for epidemics of meningitis across “Meningitis belt” of Sub-Saharan Africa, until Men A monovalent vaccine introduced in 2010 (still epidemics, but due to other serotypes). Hajj also triggers outbreaks.
  • B – 4 component vaccine introduced in 2015 to deal with B being the most common cause of invasive meningococcal disease since introduction of MenC vaccine. Based on vaccine developed for New Zealand epidemic.
  • C – used to be most common cause of invasive meningococcal disease in UK until vaccine introduced. So successful that early dose was dropped from routine schedule, although later resurgence in older children and young people, so teenage booster and university catch up programme introduced.

Clinically, notorious for rapidly evolving, often fatal septicaemia with non blanching rash and limb ischaemia. Curiously, meningococcal meningitis, on the other hand, is the most benign of the various causes of bacterial meningitis. Can be mixed picture, ranging from a few petechial spots only with an otherwise typical meningitis presentation, or else meningococcal septicaemia with neck stiffness, where presence of meningitis is actually a good prognostic sign.

Exquisitely sensitive to antibiotics. Meningitis epidemics in Africa treated with single IM dose ceftriaxone!!! Nasal carriage is the reason for spread, so prophylaxis for close contacts important.

History of Medical Failures

Where to start!? Leaches, blood letting, pretty much everything doctors did in the pre-modern period…

Thalidomide and birth defects, of course. But unforeseen.

X-rays for pregnancy monitoring. Took years before people paid attention to the alarms. X-rays were also used for tinea capitis – not just brain tumours, strokes and ischaemic heart disease about 30% higher too.

Ribavirin (via SPAG machines) for RSV. Not harmful, just useless and expensive.

Iron supplements for preterm babies – increased sepsis.