What is Erythema Migrans?

Erythema (chronicum) migrans is the name of the red circular spot that sometimes appears on the skin after a tick bite. The erythema migrans occurs at the spot where the tick has bitten and is characteristic of Lyme disease. Not everyone who is bitten by a tick develops an erythema migrans, but those who do likely have Lyme disease. However, this does not mean that everyone with Lyme disease will get an erythema migrans. You can also be infected without this symptom.

Recognizing Erythema Migrans?

The erythema migrans usually develops a few days to several weeks after the tick bite. The red spot gradually becomes larger and fades in the center. A ring often forms around the spot of the tick bite. If you have been bitten by a tick and a spot appears that resembles erythema migrans, see your doctor as soon as possible. Lyme disease is easier to treat if recognized in its early stages.

Erythema Migrans Treatment

According to Dutch guidelines, an erythema migrans is treated with a course of antibiotics for a maximum of fourteen days. However, the International Lyme and Associated Diseases Society (ILADS) recommends a course of six weeks.

Note: It is important to take a picture of the erythema migrans (almost) every day to track how the spot develops.