Bull’s eye rash — sufficient sign to treat for Lyme disease

Author: Jo Carlowe
Bull’s eye rash — sufficient sign to treat for Lyme disease

People presenting erythema migrans, the characteristic skin rash associated with Lyme disease, can be diagnosed and treated without the need for blood tests.

In a final quality standard published today, The National Institute for Health and Care Excellence (NICE), emphasises the importance of quick diagnosis and treatment.

The updated quality standard stresses the need for immediate treatment where appropriate, with identification of the bull’s eye rash sufficient for clinicians to feel confident to treat the condition.

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 and treating Lyme disease.”

Laboratory tests, such as the enzyme-linked immunosorbent assay (ELISA), check for antibodies in the blood. However, Lyme disease antibodies may first appear six to eight weeks after a person has been bitten, so an early ELISA test (one performed within four weeks of symptoms starting) may not detect the disease.

If the ELISA is positive or symptoms continue for 12 weeks of more, an immunoblot test should be used to confirm Lyme disease. People who do not have the rash and had a negative result from an early ELISA should have an ELISA repeated at the four- to six-week mark if Lyme disease is still suspected.

After a diagnosis of Lyme disease, a person will receive an appropriate course of antibiotics based on their symptoms.

NICE has published a visual aid that details the different routes to diagnosis.

NICE is also encouraging local authorities to work with other organisations (including outdoor and recreational organisations) in their area to help raise awareness of how to prevent Lyme disease.

These activities could include displaying leaflets with advice on tick prevention and removal in local GP practices, for example.

Saul Faust, professor of paediatric immunology and infectious diseases at the University of Southampton and chair of the guideline committee, said: “Lab tests are necessary when a person’s symptoms are unclear, but they are not needed if a person presents the characteristic red rash, erythema migrans. Doctors should feel confident to prescribe antibiotics immediately for those with erythema migrans.”