Lyme disease: watch out for tick bites

By Cristiano Antonino On Jul 3, 2022

Lyme disease (or borreliosis, Lyme disease) is on the list of rare diseases and in recent years there has been an upward trend in cases

The bacterial spirochete infection (Borrelia burgdorferi) that causes the disease can be transmitted to humans through the bite of a tick, with symptoms that are difficult to detect and relapses that are often very disabling.

Lyme disease

Two factors contribute to a person contracting Lyme disease: the tick (Ixodes ricinus) responsible for the bite must contain the bacterium Borrelia within it (gut and salivary glands) and it must remain attached to human skin for a long time (the risk of infection is greatly increased if it remains attached for more than 12 hours or several days).

However, Borrelia that enters the bloodstream often cannot survive and cause infection, as it has to adapt to the human environment and protect itself by its immune system.

Lyme disease: diagnosis

In addition to the clinical picture of the disease based on symptoms, the diagnosis for Lyme disease is made by a blood test (ELISA, Chemilluminescence, Western blot are the tests used for serological confirmation).

But it takes a few weeks before undergoing the test – i.e. from the tick bite to the diagnostic verdict – because the appearance of antibodies to borrelia is not so immediate.

Borreliosis: symptoms

The first symptoms of borreliosis usually include a circular skin erythema at the site of the bite, which can spread or migrate to other parts of the body: it is initially small and red in colour, but can reach up to 50 cm in diameter.

Less common are enlarged lymph nodes, sore throat, nausea and vomiting.

After a few weeks more than half of the patients may develop arthritis, as well as neurological changes or heart problems.

If Lyme disease is diagnosed in time, targeted antibiotic therapy (doxycycline, amoxicillin) can be used; otherwise, if the infection is more severe, intravenous or intramuscular administration of ceftriaxone is used, the duration of which depends on the type of further symptoms, such as neurological or cardiac complications or arthritis. In a small percentage of cases, symptoms may persist for a few months, even more than six months.

Prevention: Beware of tick bites

The tick or Ixodida (Ixodes ricinus or the wood tick and Rhipicephalus sanguineus or the brown dog tick), is a mite that feeds on the blood of the vertebrate host.

Ticks are small in size (maximum 6 mm) and are haematophagous parasites whose bite, whether of humans or other animals, may occur without giving local symptoms, at most a bit of itching; often, one notices by chance that one has one, nestling in the skin.

Their bite, which is often painless, can be a vehicle for infection, but this is a rare occurrence because it is not certain that the tick is infected with a germ, and if it is, it may not even transmit it to humans or may transmit it in quantities that do not cause problems.

Moreover, in most cases, the infection is neutralised by the immune system.

It remains, however, an important eventuality that should not be underestimated in the event of a bite.

For the time being, the only useful strategy is to protect yourself against tick bites if you visit high-risk areas, such as forests or meadows with tall grass.

After visiting a place where ticks might be present, it is a good idea to carefully check the entire skin surface, clothing and any pets.

Always inspect exposed parts, especially the head, chest, armpits and groin, where they are most likely to lurk.

It is important to remove ticks correctly and not to leave parts of the rostrum in the skin: use tweezers, extracting the tick with a gentle twisting motion.

Remedies such as vaseline and denatured alcohol are useless because they do not numb or kill the tick; moreover, if they are only partially removed, the parts left embedded in the skin lead to the formation of nodules that may mistakenly look like tumours.

It is useful to disinfect the affected area and, in the event of suspicious symptoms, an infectious disease assessment is necessary to establish which disease has been transmitted, with the prescription of antibiotic therapy best suited to treat the diseases triggered by the tick bite.

Ticks and human diseases

There are three human diseases transmitted by ticks in our country.

In addition to Lyme disease, meningo-encephalitis is also transmitted by Ixodes ricinus, the wood tick, which loves a humid climate and is mainly found in the forests of northern Italy.

The other disease is Mediterranean button fever transmitted by Ripicephalus sanguineus, the dog tick.

This parasite prefers hot dry climates and is quite common in central and southern Italy, especially in Sicily.

Symptoms are generally unspecific and include mild fever, headache, muscle and joint pain and general malaise.

What To Do In Case Of A Snakebite? Tips Of Prevention And Treatment

Insect Bites And Animal Bites: Treating And Recognising Signs And Symptoms In The Patient

How To Protect Yourself From The Bite Of The Violin Spider (Or Brown Recluse)?

What Is Lyme Disease And What Are Its Symptoms?