Facial palsy in children in endemic areas

High frequency of paediatric facial nerve palsy due to Lyme disease in a geographically endemic region. Munro A et al. International Journal of Pediatric Otorhinolaryngology 132 (2020)

This paper looks back at records of children presenting with a facial palsy at Southampton Hospital’s emergency department or paediatric assessment unit in the years 2010 – 2017. This is before the NICE guideline was published.

The authors found that diagnosis and treatment was inconsistent and variable.

Because of these findings, the authors suggest that areas with endemic Lyme Disease should consider local guidelines for paediatric facial nerve palsy, and that all children with facial palsy in those areas should be tested for Lyme disease.

The paper also raises, in LDA’s opinion, some interesting questions:

  1. When is Lyme serology “positive” from a treatment decision point of view? The paper gives the detailed results of patients said to be “positive”. In LDA’s experience, some of these would have been theoretically classed as negative because although the C6 test is a good positive, the immunoblots in 5 of those were negative or equivocal. To us, that demonstrates
    1. the usefulness of the doctor knowing the C6 numerical result (which they usually don’t), or the lab at least emphasising the high C6 result;
    2. the value of an experienced clinician taking a decision that “other causes have been ruled out, let’s assume Lyme disease”, as this seems to have happened in these cases.
  2. Tick infection rate: be careful with Borrelia figures! The authors say “Up to 30% of Ixodes ricinus ticks are seropositive for Borrelia burgdorferi in some areas”. However, if you follow that through to the origin of the 30%, you find the paper looking at some sites around the city of Salisbury (not the New Forest). At one site, the Spring collection only, of 50 ticks, had 9 positive for pathogenic Borrelia species – 18%. 6 ticks were “not typed” and could have been the probably non-pathogenic B valaisiana which was the most common genospecies at other times on the site. This is nit-picking really, but it matters that we all stick to the facts. At the time of writing 18% is the highest infection rate of Lyme disease Borrelia in a UK tick sample.
  3. Recovery rate – the outcome. The authors weren’t able to determine outcomes as this wasn’t always in the patient record but “outcomes of childhood facial nerve palsy (such as time to resolution) are excellent in general”. This study was looking at paediatric facial nerve palsy, and to emphasise that a Lyme disease diagnosis (and treatment) is important, the authors state “outcomes following treatment of Lyme disease are excellent, recently confirmed by large adult population studies in Europe of Lyme neuroborreliosis”. Really? What does “excellent” mean?

The paper the authors reference for these “excellent” recovery rates (Obel et al 2018) has two sentences in its conclusion:

  • A verified diagnosis of Lyme neuroborreliosis had no substantial effect on long term survival, health, or educational/social functioning.
  • Nevertheless, the diagnosis decreased labour market involvement marginally and was associated with increased risk of haematological and non-melanoma skin cancers.

It is slightly worrying that doctors writing papers written for, and read by, other doctors, persist in quoting only that first sentence.

If GPs knew that Lyme disease patients, although surviving just as long as other people, actually had more days sick leave in the 2 years following diagnosis and an increased use of haematology and neurology services for several years, they would be able to understand their own patients better.

Some doctors seem keen to emphasise that Lyme disease is easy to cure and does not have long term effects. Promulgating this unjustified view is not helpful to anyone.

For children in endemic areas, though, this paper should have raised awareness of Lyme disease and enabled more children to be correctly diagnosed and treated.