Lyme disease diagnosis on the NHS

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Lyme disease can be diagnosed by blood test, or by recognising a distinctive erythema migrans rash, according to NHS guidelines. The usual procedure on the NHS is described below.

I have been bitten by a tick. What should I do?

If possible, save the tick when you remove it so you can show it to your doctor. You can sellotape it onto a piece of paper.

When should I go to the GP?

1. Go to the GP if you are sure you have been bitten by a tick

He or she may order a blood test right away. If Lyme disease tests are done up to 6 weeks after a tick bite, there is a very real chance they will be negative because antibodies have not had time to form. If it is negative, the test MUST be repeated after 6 weeks.

Some doctors do not know that they must re-test; if necessary, refer them to the current treatment guidelines on Lyme disease.  If your GP refuses to send you for a repeat Lyme test, but you still have symptoms, we suggest you show him or her the full guidelines issued by Public Health England.

Some doctors suggest waiting to see if you develop Lyme disease symptoms before testing or treating. Delayed treatment is believed to increase the risk of long-term, persistent symptoms, so delaying treatment for more than 6 weeks after a tick bite is not advissable.

You may wish to ask your doctor for a printed copy of your test results to keep for your records.

2. Go to the doctor if you have at least two symptoms of Lyme disease, even if you do not remember a tick bite

Check our Lyme disease symptoms page. You may wish to print the page to discuss your symptoms with your doctor.

Be prepared to explain to your doctor how severe and frequent each symptom that you have is, and to give specific examples of what you can no longer do as a result of having this symptom. For example, everyone gets headaches sometimes, but people with Lyme disease can get headaches that last 3 weeks at a time. Everyone feels tired sometimes, but people with Lyme disease are sometimes too tired to eat food or sit and watch a film on TV. Everyone forgets things sometimes, but people with Lyme disease sometimes forget the way to the office where they work, or forget the faces of friends and fail to recognise them.

3. Go to your GP if you have an erythema migrans rash, like the main photo on this page, even if you DO NOT remember a tick bite

If there is an erythema migrans rash, you definitely have Lyme disease and you should be prescribed the standard dose of antibiotics right away. Blood testing is not necessary because the rash proves you have Lyme disease.

However, there are various types of rash which can look very similar to an erythema migrans. There are also various types of erythema migrans which may not look very much like the “target” type photograph on this web page. In other words, recognising an erythema migrans is generally acknowledged to be difficult in some cases.

Take some good photos of your rash for your records. You will then be able to show them to other doctors if you are referred to a specialist at a later date. It is important that some of your photos include your face, as doctors are obliged to be able to verify the identity of a person in the photograph if using them to assist diagnosis.

I had a bull’s-eye rash – does this mean I have Lyme disease?

Yes. The NHS guidelines say that the erythema migrans (EM) or “bull’s-eye” rash is proof of Lyme disease, and you should be treated with antibiotics without the need for a blood test.

This is a classic bull's eye rash, but many people have less distinctive rashes

However, your rash must be identified and confirmed by a doctor. It can be difficult to identify what is a Lyme disease rash, and what isn’t. Some other rashes can look similar to the Lyme disease rash, including ringworm, cellulitis and spider bites. Lyme disease rashes do not hurt or itch at all, which is a useful clue to distinguish them from other bites which may be very painful.

The photo above shows a “classic” bull’s eye rash, but many people have less distinctive rashes. For this reason, some GPs are reluctant to diagnose their patients on the basis of rash alone.

We suggest that you take photos if you have a rash, so you can show your doctor or, if necessary, a specialist even after the rash has gone.

Additional resources for General practitioners

General practitioners working in areas where there is a lot of Lyme disease are likely to have far more knowledge and experience than those who live in areas where Lyme disease is rarer. There are some resources which may help.

Current treatment guidelines

The current NHS treatment guidelines are issued by Public Health England. They explain, amongst other things,

  • the diagnostic criteria, including blood tests,
  • the medical history that your GP should record on the form requesting blood testing services for Lyme disease from the national reference laboratory (which we are told many doctors currently omit to do), and
  • the antibiotic treatments currently recommended.

RCGP course on Lyme disease

There is a RCGP (Royal College of General Practitioners) online course for GPs about Lyme disease. This gives a rapid overview of all aspects of diagnosis and treatment.