Lyme disease is an infection transmitted by the bite of a tick. Prompt diagnosis and early treatment helps reduce the risk of further symptoms developing.

Erythema migrans/James Gathany

Laboratory tests check for antibodies in the blood however Lyme disease antibodies may first appear six to eight weeks after a person has been bitten by a tick. Early laboratory tests may not detect the disease and could slow diagnosis.

The Lyme disease interviews

Erythema migrans is a skin rash associated specifically with Lyme disease and is present in approximately two-thirds of all cases. It is a spreading red rash that usually appears one to four weeks following a tick bite and can have a bull’s-eye like appearance. When there is no rash, lab tests can be used to guide a Lyme disease diagnosis, the guidance says.

Professor Gillian Leng, deputy chief executive and director of health and social care at NICE, said: “For most people with Lyme disease, a course of antibiotics will be effective, so it is important we diagnose and treat people as soon as possible.

“A person with Lyme disease may present with a wide range of symptoms, so we have clear advice for professionals about the use of lab tests for diagnosis and the most appropriate antibiotic treatments. If a characteristic bull’s eye rash is present, healthcare professionals should feel confident in diagnosing Lyme disease.”

Lyme discovery: Borrelia bacteria hides inside parasitic worms, causing chronic brain diseases

In the absence of erythema migrans and presentation of other symptoms, an initial ELISA laboratory test can be used. If this initial test is carried out too early for antibodies to have developed, people may have a negative result and the ELISA test may need to be repeated.

Read more at NICE