Lyme disease is probably the most common tick-borne illness in the U.S., and the best understood. It’s a regional disease, very common in some areas, vanishingly rare in others for reasons that aren’t yet clear. There are about 35,000 cases reported yearly in the U.S., but this likely underestimates the true incidence as many people either don’t seek help or are not properly diagnosed.
Many people present with the classic “bullseye” rash, but many (about 20-30%) do not. During the first month after infection, many people experience fatigue, fevers, and joint aches. At this point testing is rarely necessary and the disease can be treated with a short course of antibiotics based on the symptoms and physical exam alone. During this early stage, some people may get more serious symptoms, such as facial paralysis, meningitis, and heart problems. If the infection goes untreated, many people will get recurring joint inflammation, with large joints such as the knees becoming swollen, red, and warm.
Antibiotics are still effective even at this later stage of the disease, but if left untreated, some people experience lingering symptoms. In general, these ease up over time, and once treated with a standard course of antibiotics, no further antibiotics are of any help. There is a great deal of controversy surrounding this “post-treatment” or “chronic” Lyme disease. The evidence from many well-conducted studies is unequivocal. Whatever it is that ails people with so-called chronic Lyme disease, it cannot be treated with antibiotics. There is a temptation for people with no clear history of the disease and negative blood tests to blame a wide array of symptoms on “chronic Lyme disease” but despite decades of research, this has never been confirmed. There is an entire medical industry devoted to giving patients with so-called chronic Lyme disease long-term IV antibiotics, and using blood tests that haven’t been validated to make the diagnosis.
It very well may be that people who have been cleared of infection with the Lyme bacteria may experience lingering symptoms, but these do not represent infection and cannot be treated with antibiotics. At this point, the best approach is to look for the proper diagnosis and treat symptoms as they arise.
Prevention is the most important treatment. Avoiding areas where you are likely to be bitten by ticks, limiting exposed skin, removing ticks promptly, and using DEET-based repellants will help protect you.
Peter A. Lipson, ACP Member, is a practicing internist and teaching physician in Southeast Michigan. After graduating from Rush Medical College in Chicago, he completed his internal medicine residency at Northwestern Memorial Hospital. This post first appeared at his blog at Forbes. His blog, which has been around in various forms since 2007, offers "musings on the intersection of science, medicine, and culture." His writing focuses on the difference between science-based medicine and "everything else," but also speaks to the day-to-day practice of medicine, fatherhood, and whatever else migrates from his head to his keyboard.