Introduction
When people talk about ticks, they are always afraid of the diseases they transmit. In principle, there is a whole range of so-called “zoonoses”, i.e. infectious diseases transmitted to humans via animals, which are spread by ticks. In Central Europe, however, the most common are early summer meningoencephalitis (TBE) and Lyme borreliosis.
TBE, a disease caused by viruses, initially manifests itself through flu-like symptoms. This is later followed by inflammation of various organs, including the heart and brain. However, the TBE virus does not cause a skin rash.
In contrast, a special form of rash is the main symptom of Lyme disease in its early stages. This is the so-called “erythema chronicum migrans”, in English: “wandering redness”. How to recognize and treat this rash and the other accompanying symptoms of Lyme disease is explained in the following article.
Causes
The cause of Lyme borreliosis and its wandering redness is usually the bacterium Borrelia burgdorferi or a related species of bacteria. This worldwide occurring bacterium is almost only transmitted by the common wood tick, but in rare cases also by mosquitoes or horseflies. The skin rash caused by them is merely an expression of the first of the three stages of Lyme disease. It is caused by the immune cells of the body’s own defence system. These follow the bacterium, which spreads by about 3 mm per day, and cause a visible reddening of the skin by increasing the blood circulation.
SymptomsLooks of the rash
The so-called wandering blush is the main symptom, which enables the doctor to recognize Lyme disease at an early stage. Erythema chronicum migrans” is the circular, non-scaly skin redness that forms on average 1.5 weeks, but often within the first week after the tick bite around the bite site. The rash is typically painless, does not itch and is sharply demarcated from its surroundings.
If left untreated, the rash spreads in a ring shape over the surrounding skin in the following weeks. The larger its diameter, the paler the ring usually becomes. In the center of the rash, the skin is usually much paler.
A solid nodule or a slight blistering can often be observed directly at the injection site. This unique form of skin rash (and it alone!) is an indication of an active disease as a result of a tick bite, since it only occurs as a result of Lyme disease.
Other tick-borne infectious diseases, however, do not cause a rash. In the course of the removal of the tick, it is not uncommon for small skin injuries to occur, which then lead to a reddening of the skin directly at the bite site. However, this is insignificant and should not worry you.
Likewise, allergic reactions to the saliva of the tick may occur – here a flat skin rash with blistering develops, which does not indicate Lyme disease. If the rash appears all over the body, this is an indication that the cause is not the tick bite, since the migration redness is always strictly localized. Of course such a rash should still be clarified by a doctor.
In addition to the characteristic rash and the increased antibodies in the blood a few weeks after the tick bite, a number of other symptoms confirm the diagnosis of Lyme disease. These accompanying signs of the disease are generally rather unspecific, so that they are only in combination with the above mentioned symptoms proof of Lyme disease. They mainly occur in stage I of the Lyme disease, when the bacteria connect to a lymphatic or blood vessel and can thus spread in the body.
These unspecific general symptoms are first and foremost: the so-called lymphocytomas are a little more specific. These are soft, nodular swellings that discolor the skin blue-red. They appear mainly on the earlobes, nipples and in the genital area.
Although they are a common side effect of Lyme disease, they can also occur in the context of viral diseases. If the disease is not detected and treated early, stages II and III of the disease follow. Weeks to months after the actual tick bite, neurological symptoms such as paralysis of the mimic facial muscles and (neuropathic) nerve pain first appear.
In addition, inflammation of various organs, especially the heart, skin and joints may occur. However, the rash has already subsided in these advanced stages.
- Fever
- Headaches
- Muscle and limb pain
- Conjunctivitis (conjunctivitis)
- Swelling of lymph nodes
The erythema migrans, the characteristic skin rash of Lyme disease, is in many cases neither accompanied by pain nor itching, which is why it is not taken seriously by many patients. In some cases, however, it can actually itch.
Especially patients with chronic Lyme disease report that the central nodule directly at the tick’s bite site starts itching at regular intervals. However, it should be noted that many people are allergic to the saliva of ticks. Like other allergic reactions, the following one is often accompanied by a flat rash, which differs from the migratory redness clearly by its blistering.
It is also usually accompanied by itching. Apart from this, it should be noted that the bites of the blackfly are often wrongly interpreted as the result of a tick bite. In contrast to this, black flies bites are accompanied by severe itching, pain and significant overheating of the skin.
Ultimately, this means that itching is only in rare cases due to an infectious disease transmitted by ticks. Other causes are more likely to be involved in itchy skin rashes. Nevertheless, a visit to a doctor is always advisable if there are concerns or doubts about the rash.
A rash following a tick bite is typically localized around the tick bite and spreads from there. A rash all over the body, on the other hand, is rather untypical, but may indicate a general allergic reaction. This results in the formation of wheals all over the body.
However, since a tick bite is often contracted outdoors, it is not always clear whether the tick is the origin of the rash. Various grasses can also cause a rash all over the body. This is especially true if the body is exposed to a lot of sunlight at the same time. The combination occasionally leads to a rash all over the body.
