Know the signs of Lyme disease to avoid unnecessary treatment

BOSTON — Overdiagnosis and over-treatment of Lyme disease are common problems.

“There are many reasons for misdiagnosis,” said Paul Mead, MD, of the CDC’s Division of Vector-borne Infectious Diseases. Specifically, some people will get an immediate reaction at the site of a tick bite that is not necessarily caused by the disease; others have skin diseases like eczema and fungal infections that can cause ring-like lesions that may resemble Lyme disease.

Still another problem with misdiagnosis are false positives for the spirochetes that cause Lyme disease some months or years after successful antibiotic treatment, according to an article in The Journal of Infectious Diseases.

But overdiagnosis and overtreatment can be reduced with a careful history.

Erythema migrans

Source: dermatlas.org

“The highest rate of reported Lyme disease is in kids between the ages of 5 and 9 years old, so they are certainly a high risk group,” Mead said. He said physicians need to take a careful history about the nature of the rash, exposure to ticks, and the patient’s recent activities, such as camping trips or outdoors hikes. Early Lyme disease typically presents as an influenza-like illness, with fever, chills, fatigue, muscle and joint pain, swollen lymph nodes, and a characteristic ‘bull’s eye’ rash, erythema migrans, that spreads outward from the site of a recent tick bite.

Late-stage Lyme can have many manifestations, including arthritis, central nervous system effects and even an irregular heartbeat.

Treatment for early Lyme disease usually includes two to three weeks of oral antibiotics, typically doxycycline in adults and amoxicillin in children younger than 8.

But antibiotics may be overused for Lyme’s treatment. One study recently revealed that tests might show the apparent persistence of spirochetes that may not actually be present.

Spirochetal persistence?

Miikka Peltomaa, MD, PhD, research fellow here at the Otolaryngologist Center for Immunology and Inflammatory Diseases, division of rheumatology, allergy and immunology, Massachusetts General Hospital, Harvard Medical School, led a study which looked at patients with early or late disease, for whom archival samples were available at the time of antibiotic treatment and about six months or years later.

Eight of the 24 patients with early manifestations and 18 of the 21 patients with late manifestations had a fourfold or higher decline in immunoglobulin G (IgG) anti-variable surface antigen (VlsE) of Borrelia burgdorferi titers about six months after successful antibiotic treatment. Of 32 additional patients, 13 with early manifestations and five with late still had positive anti-VIsE titers 8 to 15 years after successful treatment.

With their results, Peltomaa’s group concluded that antibody response to the VlsE (IR6) peptide of B. burgdorferi often persists after successful antibiotic treatment for Lyme disease, particularly in those with late infection. They concluded persistence of the anti-VlsE antibody titers for months or years after antibiotic treatment cannot be equated with spirochetal persistence.

They postulated that during hematogenous dissemination of the spirochete, bloodborne spirochetes expressing the VIsE lipoprotein may stimulate naive B cells in the spleen to produce antibodies to the immunodominate VIsE peptide in the absence of T-helper cells. If antibiotics are administered quickly, memory T and B cells may not develop. However, the B cells may present antigen to T-helper cells, and spark adaptive immune responses presumably to the VIsE peptide and most other B. burgdorferi proteins, thus leading to the generation of memory T and B cells. They said this response might persist, despite apparent spirochetal eradication. idn

For more information:

• Peltomaa M, McHugh G, Steere AC. Persistence of the antibody response to the VIsE sixth invariant region peptide of Borrelia burgdorferi after successful antibiotic treatment of Lyme disease. J Infect Dis. 2003;187(8):1178-1186.