When should you suspect you might have Lyme disease?

Q. When should you suspect you might have Lyme disease?

A. Lyme disease is an inflammatory disease caused by a bacterial infection from a tick bite. Massachusetts is among the states with the highest rates of Lyme disease, and infection usually occurs in the summer months. Most people who get infected recover fully if treated, but in some cases it can lead to long-term health problems.

The disease can be tricky to recognize because symptoms vary and can be mistaken for milder illnesses. Jonathan Edlow, vice-chair of emergency medicine at Beth Israel Deaconess Medical Center, says that most people have initial symptoms within a week or 10 days of getting a tick bite. They feel generally ill and may have a fever, headache, muscle pain, and stiffness. Most patients also develop a rash on their skin. The hallmark rash of Lyme disease is a bull’s-eye shape: redness with a clear area around the small red center of the bite. But Edlow emphasizes that many rashes look different, often a large oval or round splotch of redness. The rash is usually closer to the center of the body than to hands and feet; typical locations include the upper legs, torso, armpits, and the hairline of children. Unlike most rashes from bites, this one tends not to be painful and itchy.