Lyme disease

What is Lyme disease?

Borrelia (Lyme disease) is caused by an infection resulting from a tick bite. The tick (shown above) often buries its head into the skin.

Lyme disease is an infection that derives from 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.

What causes Lyme disease?

Lyme disease is caused by an infection from a micro-organism (Borrelia burghdor feri), itself transmitted by a bite from the wood tick, a blood-sucking parasite which normally lives on deer.

The wood tick is found in many areas, particularly in forests where deer are common. A tick will settle anywhere on a human 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 in its probe to draw up blood, exposing the host to the risk of infection.

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, so consult your GP if you detect the following symptoms.

• A red spot around the location of the tick's bite. The spot will gradually grow bigger, often with a pale area in the middle. This symptom is called erythema migrans.
• Erythema migrans can also appear at other places on the body where the tick has not bitten. Some people get many red spots.
• Usually one to four weeks will pass between the bite and when erythema migrans appears.

Some patients with Lyme disease feel like they have caught influenza - the symptoms may be:

• drowsiness
• headaches
• mild fever
• joint and muscle pains
• swollen lymph glands.

What complications may occur?

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
• bluish or reddish discoloration of the skin.

Neuro borrelia

About 15 per cent of people with borrelia develop so-called neuro borrelia, between one and five weeks after the tick bite. The central nervous system is affected and the symptoms that result are very mixed and not specific.

• The symptoms often begin with 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.
• Sometimes neuro borrelia may present itself as meningitis, with fever, headache and stiffness in the neck.
• In rare cases, the disease may become chronic, with a slowly developing destruction of the nervous system, numbing, partial hearing impairment and the development of dementia.
• Neuro borrelia demands immediate treatment, usually with an admission to hospital.

Inflammation of the joints or Lyme arthritis

This condition may present itself in days or, rarely, years after the bite, but it is very rare. 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.

Effects on the heart

Lyme disease may cause:

• inflammation of the heart tissues, along with arrhythmia
• heart failure may develop in severe cases.

How does the doctor make the 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.

To make a firmer diagnosis the doctor may take a blood sample to determine whether the patient has developed an antibody towards Lyme disease 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. This means that people may have Lyme disease even if antibodies are not present at 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.

Possible further development

With immediate and appropriate treatment the erythema migrans rash will often disappear within two weeks. Even without treatment, most cases of erythema migrans will go away without leaving permanent effects. But treatment lessens the risk of later symptoms in your nervous system and joints.

If the nervous system, joints, or heart are affected, two to three years may pass before the symptoms go away.

In rare cases a chronic disease with permanent symptoms may develop. This may happen several years after the tick bite.

What can the doctor do?

In the early stages (erythema migrans) oral antibiotic treatment may be sufficient.

If there are other symptoms, he or she will arrange hospital admission for further investigation and possible further treatment with antibiotics.

Medical treatment

Medicines 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.