Lyme disease is a bacterial infection caused by a spiral shaped bacteria called Borrelia and is transmitted via an infected tick bite. Ticks can carry other infections such as Anaplasma and Babesia. Tick borne encephalitis (TBE) has also been found in a small number of ticks in the UK. Ticks are arachnids and can be as small as a poppy seed (Figure 1).
Figure 1. Ticks laid next to a 5p coin. They can be as small as a poppy seed
Risk of Lyme disease in the UK
Infected ticks can be found all over the UK and are found in woodland, heathland and parkland, but have also been found in urban parks and gardens. You can be bitten and infected at any time of the year, but ticks are most active from March to October. The Big Tick project (2015) found ticks on 1 in 3 dogs that their owners were unaware of.
Removing a tick
Never pull a tick off with your fingers, standard tweezers or any other tool not designed for the job, and never smother the tick in oil, Vaseline or any other substance.
Ticks should be removed using a tick remover or a pair of very fine tipped tweezers, ensuring all parts of the tick are removed. A tick remover should be an essential piece of equipment for health care settings.
Ticks can be saved and tested for infections, although this does not confirm infection has been transmitted by the tick.
There is no minimum time a tick needs to be attached to pass an infection, but it should be removed as soon as possible to reduce risk.
Useful resources on diagnosis and treatment for health professionals
Lyme Disease UK. Key Points on Diagnosis, Testing and Treatment. https://youtu.be/21NeqaGDgiE
Lyme Disease UK. Tick removal advice. https://lymediseaseuk.com/tick-removal/
National Institute for Health and Care Excellence. Lyme disease guidance. www.nice.org.uk/guidance/ng95
Royal College of General Practitioners. Lyme disease toolkit. www.rcgp.org.uk/clinical-and-research/resources/toolkits/lyme-disease-toolkit.aspx
The Big Tick Project. www.msd-animal-health-hub.co.uk/KBPH/pet-advice/parasites/big-tick-project-summary
Diagnosing Lyme disease
Lyme disease can be hard to diagnose as tick bites can be easily missed.
The most obvious sign of Lyme disease is an erythema migrans (EM) rash, often referred to as a bullseye rash. The most important thing to be aware of is the behaviour of any rash after a tick bite. An EM rash takes at least three days or more to appear, generally isn't itchy, painful or hot and gradually spreads outwards. ‘erythma’ means redness and ‘migrans’ means migrating/spreading (Figure 2).
Figure 2. Erythema migrans (EM) rash, often referred to as a bullseye rash
Redness or itchiness immediately after a bite is usually a histamine reaction. EM rashes can be atypical, do not always appear as the clear ringed type rash, and do not appear in every case of Lyme disease. They can have as solid or bruise-like appearance and will be more challenging to identify on dark skin tones.
Other symptoms with Lyme disease are ‘summer flu’, headache, neckache, fatigue, joint and muscle pain and generally feeling very unwell. Facial palsy can be an indication of Lyme disease, especially in children. Behavioural changes in small children are often a feature as they are unable to articulate that they feel unwell.
Treating Lyme disease
Early treatment is key. An EM rash is diagnostic for Lyme disease and treatment should be started straight away without the need for a blood test. The blood test used for Lyme disease is unreliable in the first 4–6 weeks after a bite and can produce a false negative result. This is because it is an antibody test, and the body can take some time to make the antibodies to the bacteria that cause Lyme disease. The blood test should be repeated if it was carried out during this early window and returned a negative result.
Doxycycline is usually the first-line treatment for adults and children over 12 years and amoxicillin is used for younger children. It is essential to be aware that treatment for children is based on their age and weight as the dosage for treating Lyme disease is much higher than other infections.
The NHS does not normally recommend treating prophylactically against Lyme disease unless pregnant or immunocompromised, although the RCGP Lyme disease toolkit does mention this for other types of high risk cases.
Tick bite revention advice can be found in Box 1.
Box 1.Prevention advice
- Tick bite prevention is crucial to avoiding Lyme disease. Insect repellent should be used during outdoor activities and permethrin treated outdoor clothing should be considered for high-risk activities
- Avoid walking through long grass and stick to well-maintained pathways
- Wearing light coloured clothing makes ticks easier to spot so you can brush them off
- Wearing long sleeves and tucking your trousers into your socks can prevent ticks from climbing up your leg and out of sight
- Showering and carrying out a thorough tick check when returning home is advisable. See Figure 3 for places ticks like to hide on your body. On young children, they are often found around the hairline and behind the ears
- Tick prevention methods should be used on pets and pets should be thoroughly checked for ticks daily. Your vet can advise on how best to protect your pet
Figure 3. Where to look for ticks on the body
Conclusion
Practice nurses should be aware of the possibility of Lyme disease in the UK. For further information visit www.lymediseaseuk.com. Lyme Disease UK can also be found on Facebook, Twitter and Instagram.