Lyme disease can be diagnosed by the eruption alone, says a new board for the NHS.
People with the "bull's-eye" circular eruption do not need a blood test and should be treated immediately to avoid complications, says the National Institute for Health and Excellence in Cure.
Expectation of laboratory results is not necessary and may cause delays in prescribing antibiotics to the patients they need.
Lyme disease is spread by tick bites and can be debilitating.
A blood test can check it but it may not give a positive result up to eight weeks after the patient has been bitten.
Professor Gillian Leng, Deputy Director and Director of Health and Social Care at the National Institute for Health and Nursing Excellence (NICE), said that for most people with the disease of Lyme, a course of antibiotics would be an effective treatment, "so it is important to diagnose and treat people as soon as possible".
"A person with Lyme disease can have a wide range of symptoms, so we have clear recommendations for professionals on the use of laboratory tests for the most appropriate diagnosis and antibiotic treatments," he said.
"If there is a characteristic rash, health professionals should feel confident in diagnosing Lyme disease."
Lyme disease can be difficult to diagnose. It has symptoms similar to other conditions and there is always an obvious rash.
Symptoms can include:
- a high temperature or feeling of heat and chills
- muscle and joint pain
- loss of energy
But if there is a delay in treatment, the most serious symptoms may develop months or years later, including:
- pain and swelling of the joints
- nervous problems – such as pain or numbness
- heart problems
- loss of memory or concentration
- Ticks that can cause Lyme disease can be found throughout the United Kingdom
- High-risk areas include grassy and wooded areas in southern England and the Scottish Highlands
- To reduce the risk of being bitten, cover the skin, put the trousers in the socks, use an insect repellent and attach to the paths
- If you are bitten, remove the tick with fine-tipped tweezers or a tick removal tool found in chemists
- Clean the bite with an antiseptic or soap and water
- The risk of getting sick is low because only a small number of ticks are infected with the bacteria that cause Lyme disease
- You do not have to do anything else if you do not feel unwell
- You should go to your family doctor if you have been bitten by a tick or have visited an area in the last month where you have found ticks infected and you have similar symptoms to the flu or a circular eruption red
- These symptoms may include feeling hot and chills, headaches, muscle pain or feeling sick
Source: NHS choices
An increasing number of high-profile people have talked about their experiences on problems related to living with Lyme disease due to a delayed diagnosis.
The American model Bella Hadid spoke about the difficulties of continuing to work with the disease because she is often exhausted and needs to take regular medications. His mother, who acted in The Real Housewives of Beverly Hills and Bella's brother, also had the disease.
The singer Avril Lavigne said that it took months for her to be diagnosed with the disease, which she had left in bed for two years. She had the first symptoms on tour when she was in pain, tired and could not get out of bed. She said she had felt so bad at some point that she "accepted that I was dying".
The former English rugby player Matt Dawson had the disease after being bitten by a tick in a London park in 2015. He caused a bacterial infection to spread through his body and eventually he left him the need for heart surgery.
Phones 4U founder John Caudwell funds a charity association Caudwell LymeCo which funds research he hopes "will lead to a truly reliable test and cure through the NHS for every patient with Lyme disease". He and 14 other members of his family have the disease.
Veronica Hughes, managing director of Caudwell LymeCo, said she hopes the new draft NICE guide will increase the number of doctors who feel confident about diagnosing an Lyme Disease at sight.
"Caudwell LymeCo Charity regularly hears from people whose doctors have diagnosed a migratory erythema but decide to check with a blood test, not realizing that the eruption is the most reliable of the two," he said.
"Waiting for the results of blood tests, always delay treatment: when a patient has a rash, this delay is not necessary and reduces the probability of total recovery".