Lyme disease is an infection that starts with a tick bite, and cases are on the rise in the UK.
Reviewed by Paul Klenerman
According to recent statistics cases of Lyme disease are rapidly increasing in the UK. This difficult-to-diagnose condition is caused by tick bites, and while treatment usually clears up the diseases in 2 to 4 weeks, sometimes more serious complications can occur.
We look at what exactly Lyme disease is, when it’s dangerous and how to prevent it:
What is Lyme disease?
Lyme disease is an infection that starts with a tick bite. The disease has a variety of symptoms, including changes affecting the skin, heart, joints and nervous system.
It is also known as borrelia or borreliosis. In the UK, nearly 1,000 cases were confirmed in the laboratory in 2011, although experts believe that 2 or 3 times this number probably occur.
What causes Lyme disease?
Lyme disease is caused by an infection with a micro-organism called Borrelia burgdorferi. This bacterium is transmitted by a bite from the wood tick (or hard-bodied tick), a tiny blood-sucking parasite which normally lives on deer, mice and other mammals, as well as birds such as pheasants and blackbirds.
The wood tick is found in many countryside areas, particularly in forests where deer are common.
The wood tick is found in many countryside areas, particularly in forests where deer are common, and in heathland. As a person walks through the countryside and brushes against the plants or grass, a tick may attach to them and settle anywhere on the body, but prefers warm, moist and dark places like the crotch or armpits.
When the tick has found a suitable place on the body, it sticks its probe in through the skin to draw up blood, exposing the host to the risk of infection. Not all ticks carry the bacteria but if they do, the bacteria may be injected into the human during the blood sucking process.
What does Lyme disease feel like?
Simply seeing a tick somewhere on your body does not mean that you have contracted Lyme disease. Unfortunately, not everyone knows when they have been bitten, as the ticks can be very tiny.
The symptoms of Lyme disease are usually divided into three stages – early, mid-stage and late-stage disease.
• Early stages of Lyme disease
A red spot around the location of the tick’s bite, which may appear any time from a few days after the bite to 4 weeks later. The spot will gradually grow bigger over a period of days and weeks, often with a pale area in the middle. This symptom is called erythema migrans, and it may expand to 30cm in diameter. It is the only symptom of Lyme disease in about 1/3rd of cases.
Erythema migrans can also appear at other places on the body where the tick has not bitten. Some people get many red spots. Some patients with Lyme disease feel like they have caught influenza with symptoms such as:
- Fatigue or drowsiness
- Mild fever
- Joint and muscle pains
- Swollen lymph glands.
• Mid-stage and late-stage disease
If Lyme disease is not treated with antibiotics, complications may appear after a few weeks or months (mid-stage Lyme disease) or even years later (late-stage Lyme disease). These are described in the next section.
Complications of Lyme disease
In most cases, Lyme disease will respond to antibiotic treatment and will clear up in 2-4 weeks. However, in more severe cases, complications can arise:
• Inflammation of the joints or Lyme arthritis
This condition may present itself in the weeks or, rarely, years after the bite, but it is rare in the UK (although it is the commonest complication in North America and Northern Europe). The inflammation of the joints causes pain and swelling.
Often, only one joint is inflamed and, rarely, more than three. The most commonly affected joint is the knee followed by the shoulder, elbow, foot, and hip. It has symptoms similar to arthritis. When treated, the swelling will go away in about one to four weeks but it may return in later months or even years.
• Acrodermatitis chronica atrophicans
This is a condition that often develops in older women. Several years may pass from the tick bite until the development of this phenomenon. The symptoms usually involve changes in the skin around the tick bite, such as swelling and bluish or reddish discolouration of the skin.
• Effects on the heart
Lyme disease may cause inflammation of the heart tissues, along with arrhythmia and heart failure may develop in severe cases.
• Neuro borrelia
This is the most common complication of Lyme disease in the UK. About 15 per cent of people with Lyme disease develop problems with the nervous system, or so-called neuro borrelia, between one and five weeks after the tick bite. Neuro borrelia demands immediate treatment, usually with an admission to hospital.
The central nervous system is affected and the symptoms that result may be very mixed and not specific, but can include:
The most common complication of Lyme disease in the UK is neuro borrelia.
🔹 Back pain, typically between the shoulder blades and in the neck like a slipped disc. The pain worsens at night.
🔹 Distorted feelings around the area of the bite. The nerves become numb, especially in the face. This may occur at any time up to four weeks after the pain began.
🔹 A facial palsy with weakness of the muscles on one or both sides of the face may develop.
🔹 Meningitis, with fever, headache and stiffness in the neck.
🔹 In very rare cases, the disease may become chronic, with a slowly developing destruction of the nervous system, numbing, partial hearing impairment, depression and the development of dementia.
How will your doctor make a diagnosis?
A diagnosis of Lyme disease is more likely if the patient remembers a tick bite and presents the doctor with the erythema migrans rash. But many people don’t notice either the tick or the rash, and the diagnosis may not be high on the doctor’s list as symptoms are very general.
To make a firmer diagnosis the doctor may take a blood sample to determine whether the patient has reacted to the bacteria and developed an antibody in their blood. Antibodies can typically be found between two and four weeks after contracting the disease, but sometimes the antibodies do not appear for up to eight weeks.
To make a firmer diagnosis the doctor may take a blood sample.
This means that people may have Lyme disease even if antibodies are not present in the very early phases, so repeat tests may be necessary in order to detect the diagnostic antibody response.
On the other hand, a positive antibody test does not necessarily mean that borrelia has recently been contracted. The antibodies may be found in the blood several years after an infection is over. Unfortunately, the antibody test is not a very efficient diagnostic tool: false-positive results are common.
If the doctor suspects neuro borrelia then hospital admission is required for tests on fluids from the spinal canal. This is to determine whether Lyme disease has entered the nervous system. In cases of chronic neuro borrelia the treatment may include a CT scan of the nervous system.
Lyme disease treatment
In the early stages (erythema migrans) oral antibiotic treatment may be sufficient. If there are other symptoms, the doctor will arrange hospital admission for further investigation and possible further treatment with antibiotics.
Antibiotics used against Lyme disease include:
- Oral doxycycline (eg Vibramycin) (except in children), amoxicillin (eg Amoxil) or cephalosporin antibiotics are the usual first choices
- When antibiotics by injection are being given, then benzylpenicillin (eg Crystapen), cefotaxime (Claforan) and ceftriaxone (Rocephin) are the usual choices
No particular choice and method is superior to another – the decision is made by the infectious disease specialist and is dependent on the individual circumstances.
How to prevent Lyme disease
It’s important to take steps to prevent Lyme disease, especially when out in the countryside as it can cause significant problems. There is currently no vaccine available against Lyme disease.
✔️ Wear trousers tucked into boots and long sleeve clothing, especially in areas where Lyme disease is particularly known to occur (such as Exmoor, the New Forest, the Lake District and the Yorkshire Moors).
✔️ Use insect repellents.
✔️ Always check yourselves, and your children (and your dog!) for any sign of ticks after going out for a walk.
✔️ Remove any ticks found very carefully, pulling steadily using tweezers or a cotton thread.