Thursday, February 17, 2011

Arthritis Due to Lyme Disease Often Overlooked

Briefly NotedLyme disease is the most common tick-borne disease in the United States and Europe, according to a recent review, but it can be difficult to distinguish from other disease processes in acute and late stages. Lyme-related arthritis is a common clinical manifestation of untreated Lyme disease and should be considered in patients with pain in only one or a few joints, and who have been exposed to geographic areas where Lyme disease is endemic — yet, this diagnosis is often overlooked.

According to the Centers for Disease Control (CDC), about 30,000 cases of Lyme disease were confirmed in 2009, but many cases go unreported. In the United States, it can occur almost anywhere but is most common in the Northeast, the Great Lakes region of the Midwest, and in the Pacific Northwest. According to a recent review paper published in the Journal of the American Academy of Orthopaedic Surgeons (JAAOS), when Lyme disease is diagnosed and treated early, most patients do not develop Lyme-related arthritis [Smith et al. 2011]. However, when correct diagnosis is delayed, Lyme arthritis can occur when spirochete bacteria that cause the disease invade the joints and promote tissue inflammation. This form of arthritis is characterized by one or several painful, swollen, and stiff joints similar to osteoarthritis, and it usually occurs several months after onset of Lyme disease. About 60% of patients who are left untreated for Lyme disease in its early stages will develop Lyme arthritis, according to the review, and if this arthritis is untreated the inflammatory response can permanently damage cartilage within the joints.

Most cases of Lyme arthritis involve a single joint, usually the knee, but the ankle, elbow, hip, and wrist also may be affected. Following an initial period of joint pain and swelling lasting from a week to several months, symptoms may subside and recur again periodically. Lyme disease and related arthritis might be suspected in individuals who live in or have visited areas where Lyme disease is known to be present, especially during warm-weather months, and symptoms may include the following: (1) a rash which develops near an insect bite on the skin, especially the characteristic target-shaped or “bull’s-eye” rash; (2) aching, redness, or swelling in one or more joints; (3) fever, lethargy, or malaise; (4) and/or, headache. A diagnosis of Lyme arthritis can be easily overlooked, especially in patients who do not develop (or did not notice) the characteristic rash of Lyme disease and in those who have fever, since it can be confused with a another type of joint infection, particularly in children.

The authors note that Lyme arthritis has an excellent prognosis of recovery if treated appropriately but the key is early diagnosis of Lyme disease to avoid development of arthritis, or to differentiate between Lyme arthritis and other types of arthritis in symptomatic patients. Lyme arthritis can be successfully treated with oral antibiotics in most patients and analgesics may help to manage symptoms while the patient is improving. A small number of patients may continue to have symptoms even after treatment with antibiotics and surgical treatment may be necessary to remove diseased synovial tissues in the affected joint(s).

REFERENCE: Smith BG, Cruz AI, Milewski MD, Shapiro ED. Lyme Disease and the Orthopaedic Implications of Lyme Arthritis. J Am Acad Orthop Surg [JAAOS]. 2011(Feb);19(2):91-100 [abstract here].