Introduction:
Lyme disease, caused by the spirochete Borrelia burgdorferi, can affect multiple systems leading to varied clinical manifestations. We report a case of an 18-year-old female who presented with myositis.
Case Report:
An 18-year-old female from Jamaica, with a past medical history of cerebellar ataxia, presented with the sudden onset of bilateral leg weakness, pain, and swelling for one day. Her symptoms were preceded by a mechanical fall with trauma to the knee. While visiting the U.S. she resided in Baychester for 4 months with no history of tick bites.
At presentation, the patient was afebrile. Physical examination was significant for new onset bilateral lower limb edema, calf tenderness, reduced power and reflexes. She uses a walker at baseline, but was further restricted in her gait. No rash was noted.
Initial lab studies showed rising CPK levels peaking at 23,028 unit/L on day 3 of admission. IV methylprednisolone was administered for 48 hours and then tapered on prednisone. Renal function was stable, venous ultrasound of the lower extremities showed no deep vein thrombosis. T2 MRI fat saturated axial images of the lower limbs showed muscular edema, consistent with myositis (Fig. 1).
Additional investigations showed: elevated transaminases (AST 292 unit/L, ALT 71 unit/L); urinalysis positive for large blood and elevated Myoglobin (1370 mcg/L). Lyme antibody with reflex to Western Blot was positive for 2 IgM bands. CPK trended down to 1,444 unit/L. The patient was subsequently discharged on Doxycycline for 14 days.
Discussion:
The clinical phases of Lyme disease include early localized, disseminated and late disease. Erythema migrans characterizes early localized disease. Disseminated disease has neurological or cardiac involvement and late disease most commonly presents as Lyme arthritis. Myositis is a rare manifestation. Patients present with localized muscle involvement, pain, swelling, tenderness and weakness of the affected limb(s). Creatinine Kinase level may be normal or elevated. Early recognition and treatment of Lyme myositis is critical, even without a history of tick bite. Diagnosis is based on clinical features, serologic studies and MRI findings. Rare manifestations like myositis can be diagnosed by muscle biopsy. PCR of musculature and synovial fluids may also serve as diagnostic adjuncts.
Conclusion:
The diagnosis of Lyme disease remains a challenge to clinicians. This case illustrates a rare manifestation of Lyme disease and prompts the consideration of Lyme myositis in cases of unexplained myositis in Lyme endemic areas.
References:
1. Holmgren, A.R., Matteson, E.L. 2006. Lyme Myositis. Arthritis Rheum. 54:2697-2700
