“TICK BOOM Billions of Lyme disease-carrying ticks on the march across England, experts warn (4)”
Okay, this isn’t a tabloid paper, but this is just an example of the coverage that Lyme disease has been getting during the summer of 2019. ‘Experts’ should refer to health care professionals who will come in to contact with suffers of Lyme disease, so let’s cut through the headlines and see what we really should know about the disease.
Lyme disease is a bacterial, tick borne illness caused by the spirochete bacterium Borrelia burgdorferi. Occurrence rates in the UK have been on the rise. However, some perspective is needed here. The UK has relatively low levels of Lyme disease prevalence. Owing to the low levels when compared with nearby countries a recent study was completed which concluded that prevalence rates are most likely higher than previously thought. A rise from 3000 new cases every year, to 8000 (2). With this new figure that gives approximately a population ratio of 1 case: 7000 people per year, this remains a low prevalence rate. Comparing that with the USA where 300,000 cases are diagnosed each year (1). Approximately a population ratio of 1 case:1000 people per year.
As you can see that there defiantly isn’t a ‘march’ of ‘Lyme disease carrying ticks’ across the United Kingdom.
So why are some people worried about Lyme disease?
As well as the revised prevalence estimate noted previously. Lyme disease can be a tricky one to diagnose clinically. The symptoms can be common and unspecified and not everyone will display the ‘tell-tale’ signs. This can be further confounded as the patient may not have even noticed the tick bite, thus the history can profoundly affect the diagnostic thought process.
NICE have produced some guidance which is currently under review detailing recommendations on Lyme disease treatment (3). Information can be found in the reference section for further reading.
The main ‘Tell-Tale’ symptom is Erythema migrans.
This is a red rash, that increases in size, sometimes has a central clearing, is usually not hot, painful or itchy, appears from 3 days to 3 months after the tick bite, can present for several weeks and is usually at the site of the bite.
What makes this diagnosis even harder is not everyone infected will present with this rash AND tick bites can cause a rash which isn’t Erythema migrans. The differentials here are that it occurs and recedes within 48hours and is more likely to be hot, itchy and painful.
Figure 1. Classic ‘bulls-eye’ style Erythema migrans (3). Figure 2: Erythema migrans lesion on the shoulder of a child,
without any clearing or ‘bulls-eye’ effect (3).
Then NICE provides a list of other non-specific symptoms the clinician should be aware of in a patient presenting with Lyme disease.
|Non-Specific symptoms of Lyme disease|
|Fever and sweats|
|Neck pain or stiffness|
|Migratory join tor muscle aches/pains|
|Cognitive impairment (brain fog)|
It’s essential in the diagnosis of Lyme disease to get a details history, including activities that increase tick exposure. For example, walking/hiking in grassy or wooded areas, wearing shorts/clothing that could expose skin during these activities. The location also plays a factor, with high risk UK areas being in the south of England and the Scottish Highlands.
Together the signs, symptoms and history should help create a clinical hypothesis. If you’re working as a Community Pharmacist, then a referral to the GP complete with the history you have taken is the next step.
If your working in a setting where you are involved in the final diagnosis, then further tests can be used to confirm or refute the presence of Lyme disease. NICE have produced a useful flow chart to describe these which can be seen bellow.
Figure 3: Lyme disease: laboratory investigations and diagnosis. (3)
It’s important to note that the laboratory testing can produce both false positives and negatives and since they are antibody tests if it is carried out too early or if the patient has a reduce immune function the test may have inaccuracies.
It is important to reassure the patient that once a confirmed diagnosis can be made the treatment consists of a course of a common antibiotic and due to this most people recover completely with no lasting effects. It may take time for this full recovery to occur, but in the months following treatment the symptoms should steadily improve. It’s also worth noting that additional treatment can be used for symptomatic relief while this occurs, ensuring the patient is fully supported during the process of recovery.
To sum up
Lyme disease prevalence is expected to be higher than first thought in the United Kingdom, but we still have a low level compared to elsewhere in the world and there is certainly no need for panic. Using sensible steps, like those for general insect bite prevention is usually enough to prevent tick bites. Only a small number of ticks will be carries of the bacteria and not every bite from an infected tick will cause an infection.
Patients and the public should be advised upon bite prevention and how to spot some of the classic signs as well as when to seek medical help. Then well-informed health care professionals should keep in mind Lyme disease as a differential diagnosis, especially when patients present with non-specific common symptoms as described above. In this way we can ensure the public have the right information and the Pharmacists, Doctors and other health professionals who can treat quickly and effectively.
Author: MJ Burgoyne
- Centers for Disease Control and Prevention, National Center for Emerging and Zoonotic Infectious Diseases (NCEZID), Division of Vector-Borne Diseases (DVBD). December 21, 2018.
- Incidence of Lyme disease in the UK: a population-based cohort study doi 10.1136/bmjopen-2018-025916
- Lyme disease. NICE guideline [NG95] Published date: April 2018.
- TICK BOOM Billions of Lyme disease-carrying ticks on the march across England, experts warn. The Sun online. 10 May 2019, 23:56Updated: 10 May 2019, 23:56. Available: https://www.thesun.co.uk/news/9050296/plague-ticks-lyme-disease-england/
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