Severity of Lyme disease with persistent symptoms. Insights from a double-blind placebo-controlled clinical trial.

Lyme disease is a global health concern and is the world's leading tick borne infection caused by the spirochete, Borrelia burgdorferi, that has been associated with numerous neurologic, rheumatologic and psychiatric manifestations. The symptoms of Lyme disease have been characterized as either severe or ''related to the aches and pains of daily living.'' A randomized double-blind, placebo-controlled clinical trial (RCT) was conducted in a primary internal medicine practice in Westchester County, New York, USA. A total of 84 adults with Lyme disease with persistent symptoms (LDPS) were studied; 52 received amoxicillin and 34 received placebo. The subjects received either placebo or amoxicillin 3 g per day orally for 3 months. The SF-36 was used as the outcome measure of the patient's perceived Quality of Life (QOL). For subjects enrolling in this RCT, the average SF-36 physical component summary (PCS) of QOL (40+/-9, range 29-44) and mental component summary (MCS) of QOL (39+/-14, range 23-46) were worse than the general USA population and worse than individuals with diabetes, heart disease, depression, osteoarthritis or rheumatoid arthritis. The improvements in the SF-36 measure of QOL for subjects randomized to amoxicillin vs. placebo was significant (46% vs 18%, P=0.007). It is important for clinicians to be aware that LDPS can be severe. A significant gain in the QOL for subjects randomized to amoxicillin in this RCT without serious adverse events is consistent with the goal of improving patient's QOL and consequently worthy of further study.