Tips For Recognising, Diagnosing and Treating Lyme Disease
Published: 21/03/24
Our colleagues at LDUK have put together the following information to help raise awareness of Lyme Disease amongst community pharmacy health professionals.
If you do have any questions please contact LDUK at: awareness@lymediseaseuk.com
Lyme disease is a bacterial infection caused by the spirochete, Borrelia burgdorferi. The infection can spread to humans via the bite of an infected tick. Lyme disease is increasing in incidence and is the most common tick-borne disease in the Northern Hemisphere. Infected ticks can be found throughout the UK, but some areas are known to be higher risk, including the Highlands of Scotland, South and South West England, and parts of East Anglia. Ticks are mainly found in grassy areas and woodlands, but have also been found in urban parks and gardens. Pharmacists are well-positioned to spot signs of Lyme disease and advise the person to consult a doctor, particularly if a person presents with a rash.
Ticks live in grassy areas and look for food during an activity known as ‘questing’. A tick waits on a blade of grass for a host to brush past it, transfers onto the host, and then crawls to find a warm spot to embed itself into. The tick will feed for up to 3-6 days, and eventually fall off if the host does not realise it is there. Ticks are usually most active from early spring to late autumn, and this was traditionally thought to be peak time for tick bites. However, with our changing climate and the UK now having milder winters with more rainfall, ticks now appear to be active in some areas throughout the year.
If a person presents with an embedded tick, it must be removed correctly and not with anything not designed for the job. Never stress the tick by covering it with anything to make it fall off (e.g. Vaseline). A stressed tick can respond by regurgitating the contents of its stomach into the host’s bloodstream. A tick should be removed with a tick tool or a pair of fine-tipped tweezers. If a tick tool is available, slide the fork-like part of the tool underneath the tick, twist the tool which will loosen the grip of the tick, and pull upwards (see instructions for the tool that you use). If using fine-tipped tweezers, grasp the tick as close to the skin as possible and pull straight upwards. Clean the area with an antiseptic wipe and advise on the type of symptoms to observe over the next few weeks. If the tick is not removed cleanly and the mouthparts remain embedded, the body will dispel them like any other foreign body, but the person should be advised to observe for any signs of localised infection that might need treatment. Retained mouthparts do not increase the risk of contracting Lyme disease.
example of an embedded tickProphylactic treatment after a tick bite is not usually recommended by the NHS, but the RCGP Lyme disease toolkit does suggest that it can sometimes be considered for certain high-risk cases. It is estimated that only about 10% of ticks carry the bacteria that causes Lyme disease, which can be reassuring when a person seeks advice after a tick bite.
examples of EM rashesThe most obvious sign of Lyme disease is an erythema migrans (EM) rash, sometimes referred to as a bull’s-eye rash. However, it is estimated that about 30% of people infected with Lyme disease do not develop a rash. As well as the typical bull’s-eye presentation, the rash can have a solid or bruise-like appearance. It can appear very differently on darker skins and can be harder to spot. The behaviour of the rash is very important when considering diagnosis. It is always delayed in appearance (from 3 days after a bite, up to 3 months), is generally not itchy or painful, and slowly spreads outwards as its name indicates. The spreading is the telltale sign of an EM rash. In some cases, EM rashes can become huge. Any redness, itchiness or swelling immediately after a bite is likely to be a histamine reaction. Other symptoms to look out for are flu-like symptoms, headache, neck ache, sore muscles and joint pain, fatigue, and feeling generally very unwell. Good history taking is essential. If an EM rash is diagnosed, treatment with antibiotics should begin straight away with no need for a blood test, as an EM rash is diagnostic for Lyme disease. Antibiotics should be prescribed as per the NICE guideline for treating Lyme disease. It is important to note that antibiotic dosages for children with Lyme disease are much higher than for other infections, and are based on the child’s age and weight. The guideline should always be consulted if the healthcare professional is not familiar with prescribing for Lyme disease.
If Lyme disease is suspected but there is no EM rash present, serology testing should be carried out. Testing for Lyme disease in the UK is a two-tier system. The first tier is an ELISA test, and if this returns a positive or equivocal result, it should be followed by the second tier of testing: an Immunoblot. This is to rule out any cross-reactions from the initial test. The Immunoblot is carried out by the National Reference laboratories at Porton Down in England and Wales, and Raigmore in Scotland. Both are antibody tests, and it is important to remember that the immune system can take some time to make antibodies to the bacteria that causes Lyme disease: possibly up to four weeks or more. Therefore, testing straight after a bite is likely to return a negative result, even if the person has been infected. If a test is carried out during this early window, testing should be repeated. The NICE guideline states that one should consider starting treatment while waiting for the results of testing if there is a high clinical suspicion of Lyme disease. It also advises healthcare professionals to be aware that testing can produce both false positive and negative results.
A new e-learning module on the management of tick bites is now available from NES. This learning resource helps support healthcare practitioners gain the evidence-based knowledge required to discuss prevention of tick bites with the public and how to recognise Lyme disease.