Recurrent Lyme Disease: Old or New Infection?

Discussion: Lyme Disease

The answer to the question is none. Given the classic appearance of the rash, the diagnosis of Lyme disease can be made and the patient treated accordingly. Given that he previously had a positive Lyme IgM and IgG, repeating his serology now will not be helpful because it would be unknown whether any positive bands were related to the previous or to the current infection. The patient was treated with 14 days of oral doxycycline, and he fully recovered.

Lyme disease results from infection with Borrelia burgdorferi, a spirochete that is inoculated directly into the skin by ticks that are part of the Ixodes ricinus complex. The disease incidence parallels the distribution of the vectors and is endemic to regions of North America, Europe, and Asia. There are some differences in the specific Borrelia genospecies that are found in these varied geographic regions, resulting in important differences in clinical presentation and treatment preferences. For clarity, this article is focused on B burgdorferi sensu stricto, the only genospecies found in the United States.The Centers for Disease Control and Prevention (CDC) estimates that approximately 300,000 new cases of Lyme disease occur in the United States each year.^[1]

The clinical manifestations of Lyme disease result from active infection and/or immunopathogenic responses to infection and involve 3 distinct stages of disease:

1. Early localized disease;

2. Early disseminated disease; and

3. Late Lyme disease.

Approximately 50% of patients with early localized disease who do not receive antibiotic treatment will progress to disseminated disease. However, all stages of disease are curable with appropriate antibiotic therapy.

B burgdorferi shows a distinct predilection for the skin, heart, central nervous system, and joints. In early localized infection, patients typically present 3-32 days after the tick bite with erythema migrans (EM), a pathognomonic rash that is characterized by an erythematous rash with a central clearing (bull's-eye rash). Because the small, nymphal form of the tick is generally responsible for transmission of disease to humans, most patients do not recall the tick bite. The EM rash occurs at the site of the tick bite, although about 20% of people do not develop a rash.

Early vs Late Lyme Disease

In early disseminated disease, patients present days to weeks after the onset of EM with extracutaneous manifestations caused by the hematogenous spread of B burgdorferi. Patients often present with a nonspecific febrile illness characterized by lethargy and fatigue or secondary EM lesions (40% of patients).^[2] Approximately 15% of untreated patients develop neurologic manifestations,^[2] including cranial neuropathy (most often involving cranial nerve VII and resulting in a Bell palsy), meningitis, elevated intracranial pressure in the absence of pleocytosis (pseudotumor cerebri), subtle encephalitis, and/or myelitis. Cardiac involvement, most commonly including any degree of atrioventricular block, affects 8% of patients.^[2] Intermittent and migratory musculoskeletal pain affecting 1-2 locations is common at this stage of disease.

Late Lyme disease occurs months to years after the initial tick bite and may be the first presentation of Lyme disease in some patients. In the United States, approximately 60% of patients^[2] with Lyme disease who do not receive antibiotic therapy develop oligoarticular arthritis in large joints, often the knees. These episodes typically last weeks to months in a given joint, although a small percentage of patients develops persistent arthritis that results in long-term damage to the joint. Chronic neurologic symptoms, although rare, have been described and generally presents as a subtle encephalopathy affecting sleep, memory, and/or mood.

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Cite this: Recurrent Lyme Disease: Old or New Infection? - Medscape - Oct 21, 2013.