Fibromyalgia; Depression; Medicaiton error. This report describes the occurrence of fibromyalgia in a 37 year old female patient who received Lyme disease vaccine recombinant OspA (LYMErix) for prophylaxis. This report was received as part of litigation proceedings. Medical records were subsequently received. The patient received injections of LYMErix on 10 November 1999, 15 December 1999, and 26 April 2000 "according to the client." This represents a 0, 1, and 5 months schedule rather than the recommended schedule of 0,1, and 12 months. On 03 September 2003, the patient's attorney alleged that the patient "suffered joint pain, headaches, memory loss, musle soreness and stiffness, head movement limitation, back and neck pain, knee and elbow pain, insomnia, left foot numbness and depression which started between November and December of 1999 according to the client." Treatment and outcomes of the alleged events were not reported. The following information was reported via medical records. The patient had a history of Lyme disease, epicondylitis, arthralgia, myalgia, fatigue, knee pain, leg numbness and leg pain. The patient received a total of four LYMErix vaccinations, on 10 November 1999, 15 December 1999, 26 April 2000, and 13 June 2001. Approximately two months after her third LYMErix vaccination, in June 2000, the patient was referred to an orthopedist for persistent bilateral knee pain. She was thought to have patellofemoral syndrome, which resolved with exercises. Within 24 hours of the 13 June 2001 LYMErix vaccination, the patient developed severe low backache, knee pain, shoulder pain, and elbow pain. The pain spread to the neck, jaw , left foot and left hand, and additional symptoms included headaches, nausea, vomiting, fatigue, difficulty sleeping, joint pains, change in memory dysasthesia and clicking and snapping of the joint tendons Impression was that of a fibromyalgia-type picture" after having received a booster dose of Lyme vaccine. Treatment included doxycycline, Vioxx and Celebrex, in addition to Percocet if needed. She experienced some improvement of symptom. On 22 June 2001, she was evaluated for worsening joint pain. There was no evidence of arthritis at that time, but the physician described "some kind of ill-defined periarticular rheumatism which may or may not be related to LYMErix". Despite the physician's recommendations to the contrary, the patient was "adamant about completing three weeks of doxycycline". She also received Tylenol. HLA typing revealed that the patient was DR4 positive. The physician stated that it was possible that the patient was experiencing residual symptoms from the Lyme disease vaccine. A bone scan and a nerve conduction study were recommended for questionable inflammatory arthritis. The bone scan performed on 12 September 2001 revealed minimal increased activity involving the right inferior sacroiliac joint, possibly reflective of some degenerative change, but otherwise normal. In September 2001, the patient reported improved food discomfort and foot dysesthesia, but noted arthralgias and myalgias following physical exertion, particularly in the foot, knee, elbows and neck. General impression was "fibromyalgia, status post LYMErix booster shot". At the same time, the patient was taking only Tylenol for her symptoms. Following the reported onset of fibromyalgia, the patient experienced decreased red blood cell count, sore throat attributed to viral syndrome, and cough (possible early pneumonia versus viral syndrome). These were not reported as adverse events due to vaccine administration, but were found during the course of review of the patient's medical records. Therefore, they are not listed as adverse events.