Lyme Disease: What’s the Benefit of Antibiotic Therapy for Long-Standing Symptoms?
Lyme disease is caused by infection with a spirochete, Borrelia burgdorfei, and by the body’s immune reaction to the infection. It was first recognized in the United States in the early 1970s when an unusual outbreak of childhood arthritis occurred in Lyme, Conn. Doctors subsequently discovered a borrelial organism from Ixodes ticks in these patients and established it as the causative agent.
Lyme disease manifestations are divided into three states: localized, disseminated and persistent.
The initial cause is a tick bite from the Ixodes tick. Thirty percent of patients do not recall being bitten. Erythema migrans can then occur, which is an erythematous lesion that increases in size over days. One third of patients with this rash develop no further symptoms of Lyme disease, while two thirds will develop more, including feel flu-like symptoms, fever and lymphadenopathy.
Occassionally patients may develop migratory arthritis. This can develop into a monoarticular process involving the knee, ankle or wrist. Some patients develop cranial nerve palsies, such as a facial palsy. Certain patients develop a meningitis type picture, while others may develop carditis with fever and syncope due to an interruption of the conduction of electrical impulses from the atria to the ventricle (AV block). Some patients even require pacemaker placement due to AV block. Eighty percent of patients with Lyme disease develop malaise and fatigue.
Ten percent of them develop chronic arthritis, and some patients develop chronic neuropathy or chronic meningoencephalitis.
Even after appropriate treatment, patients who have Lyme disease can develop symptoms consistent with fibromyalgia/chronic fatigue syndrome. It does not appear to be due to active infection.
Lyme disease is diagnosed using antibody detection tests. However, no national standards have been set for the best antigen for this test. This is further complicated by the reporting of many false-positives and false-negative results.
Currently, the U.S. Centers for Disease Control and Prevention recommends a two-step process. The first step is to order an antibody titer. This is either a total Lyme titer or separate immunoglobulin G (IgG) and immunoglobulin M (IgM) titers. The second is to confirm positive titers with a Western blot. If patients aren’t treated, they continue to produce IgM antibodies long after the initial infection. They also may have both IgM and IgG antibodies at the same time.
An article from the New England Journal of Medicine in 2001 stated that tick bites should be treated initially with a single dose of 200 mg of Doxycycline within 72 hours of removing a tick, for patients who live in endemic areas. (N Engl J Med 2001 Jul 12; 345(2): 79-84.)
If patients have skin manifestations, they are started on oral antibiotics for 30 days. For patients with arthritis, they also are treated for 30 days, and can be re-treated for 30 days with oral antibiotics or IV Ceftriaxone for 14 to 30 days if the first oral treatment is unsuccessful. Patients with facial palsies have similar treatment, and patients with radiculopathy receive IV antibiotics or oral therapy. Patients with encephalitis must undergo IV therapy for 28 days.
To date, no controlled studies have shown fibromyalgia symptoms following Lyme disease to be responsive to antibiotic therapy. A 1989 study in the New England Journal of Medicine failed to show benefit of treatment with 2 g of IV Ceftriaxone daily for 30 days followed by oral Doxycycline at 200 mg/d for 60 days. (N Engl J Med 1989 Aug 31; 321: 586-96.)
A recent article in the New England Journal of Medicine states: “There is substantial risk, with little or no benefit, associated with additional antibiotic treatment for patients who have long-standing subjective symptoms after appropriate initial treatment for an episode of Lyme disease.” (N Engl J Med 2007;357:1422-30.)
Lyme disease is a common tick-borne infection. Patients with suspected Lyme disease should have appropriate testing as recommended by the CDC. Clear initial treatment guidelines exist for initial management. Patients with fibromyalgia symptoms after the diagnosis of Lyme disease, which is common, do not gain added benefit from long-term antibiotic use and in fact it may be harmful.
Resources:
Emedicine, Lyme disease.
www.emedicine.com/med/topic1346.htm
