How is Lyme Disease Diagnosed?
Because there is no definitive test that can rule out Lyme disease, LDA believes Lyme disease should be diagnosed clinically. Symptoms overlap with many other conditions, which complicates diagnosis.
A search of the TRIP Database located a number of guidelines and eTextbook articles that discuss diagnosis but many of them are based on Lyme disease in the USA. Recently published clinical case definitions for Europe  say:
“Lyme borreliosis is very similar in Europe and North America but the greater variety of genospecies in Europe leads to some important differences in clinical presentation.”
Although European Lyme disease is known to cause more neurological symptoms and less arthritis, compared with N American Lyme disease, there have been few studies on the range of symptoms. A 2006 paper  concluded:
“Patients with B. garinii isolated from their CSF have a distinct clinical presentation, compared with patients with B. afzelii. B. garinii causes what, in Europe, is appreciated as typical early Lyme neuroborreliosis (Bannwarth syndrome), whereas the clinical features associated with B. afzelii are much less specific and more difficult to diagnose.”
See here for a list of symptoms that have been associated with Lyme disease.
Lyme disease with a rash
In approximately two thirds of cases, the patient notices a rash. The erythema migrans, as it is called, appears between 2-30 days after the tick bite.
The CKS website (Clinical Knowledge Summaries)  states:
“Testing is not generally considered to be necessary for people with erythema migrans and a history of a tick bite or possible exposure to ticks, as this presentation is sufficient to make a clinical diagnosis of Lyme disease.”
As all sources emphasise that early treatment is more likely to be successful, anyone presenting with a rash should receive treatment without waiting for a blood test.
The Map of Medicine , used within the NHS says Lyme disease:
“may begin with the characteristic skin rash, erythema migrans, in 35-60% of cases and, over a course of two weeks, spread to other sites (stage 2), including:
- synovial fluid
- connective tissue
- nervous system
- heart and joints”
Lyme disease without a rash
CKS  gives the following guidance:
Suspect early Lyme disease in people with a history of a tick bite or possible exposure to ticks when they present with any of the following:
- Flu-like symptoms – these may include fever, headache, tiredness, nausea, vomiting, arthralgia (joint pain), and myalgia (muscle pain); there are no significant respiratory symptoms.
- Neurological symptoms- occur in up to 10% of untreated people, and may present days to months after infection. People may present with one or more of the following:
- Unilateral or bilateral facial nerve palsy (or, rarely, other cranial nerve involvement)
- Radiculopathy (usually associated with pain and/or paresis)
- Meningitis or (rarely) encephalomyelitis
- Mononeuropathy multiplex — involvement of multiple, anatomically unrelated nerves
- Cardiac symptoms - Carditis is a rare manifestation of Lyme disease in the UK. It may present with syncope (fainting), breathlessness, or chest pain, usually within 2 months of infection. An electrocardiogram shows varying degrees of atrioventricular or first-degree heart block.
Consider the possibility of late Lyme disease in people with a history of a tick bite or possible exposure to ticks when they present with any of the following:
- Arthritis - Rare with UK-acquired infection, but more common when the disease is acquired in some other parts of Europe or in the US. Involves recurrent brief attacks of joint swelling in one or more large joints (most commonly the knee or, less frequently, a hip, ankle, shoulder, or temporomandibular joint) and occasionally progresses to chronic arthritis. A large knee effusion (that is often out of proportion to the pain) is typical and a Baker’s cyst may develop and rupture.
- Neurological disease - Late neurological Lyme disease can present as a slowly progressive central nervous system disorder (encephalomyelitis) or peripheral neuropathy.
- Acrodermatitis chronica atrophicans – This is an uncommon, bluish-red discolouration and swelling, on the extensor surfaces of legs and arms, that develops several years after infection. There is often associated peripheral neuropathy.
1) Lyme borreliosis: clinical case definitions for diagnosis and management in Europe. Stanek, G., Fingerle, V., Hunfeld, K.-P., Jaulhac, B., Kaiser, R., Krause, a, et al. (2011). Clinical microbiology and infection, 17(1), 69-79. doi: 10.1111/j.1469-0691.2010.03175.x.
2)Comparison of Findings for Patients with Borrelia garinii and Borrelia afzelii Isolated from Cerebrospinal Fluid Strle et al. Clinical Infectious Diseases 2006; 43:704–10