Diagnosing Lyme disease

Abstract

Michael Riedel and colleagues (Feb 7, p 418)1Riedel M Straube A Schwarz MJ Wilske B Muller N Lyme disease presenting as Tourette's syndrome.Lancet. 1998; 351: 418-419Summary Full Text Full Text PDF PubMed Scopus (62) Google Scholar describe a manifestation of neuroborreliosis. Diagnosis of Lyme disease can be difficult and guidelines have been established that involve a two-test protocol: an ELISA followed by IgG, IgM immunoblotting, or both.Although the immunoblot assay is useful in confirming false-positive ELISA results, it is not a perfect test and there is poor interlaboratory reliability.2Still MM Ryan ME Pitfalls in diagnosis of Lyme disease.Postgrad Med. 1997; 102: 65-72PubMed Google Scholar If IgG is detected rather than IgM, it may represent past infection and Borrelia burgdorferi may not be responsible for the current illness. If the pretest probability of disease based on clinical findings is low, then the positive predictive value of tests used will be low.3Sigal LH The Lyme disease controversy.Arch Intern Med. 1996; 156: 1493-1500Crossref PubMed Google Scholar Non-specific symptoms alone, such as headache, fatigue, myalgia, or arthralgia, even in endemic areas will not increase the pretest probability to the levels at which testing is clinically useful (0·20–0·80 probability).4Tugwell P Dennis DT Weinstein A et al.Laboratory evaluation in the diagnosis of Lyme disease.Ann Intern Med. 1997; 127: 1109-1123Crossref PubMed Scopus (201) Google ScholarThere are insufficient data to evaluate strategies for patients with rare manifestations such as neuro-ophthalmological disorders, and two-step testing is recommended.4Tugwell P Dennis DT Weinstein A et al.Laboratory evaluation in the diagnosis of Lyme disease.Ann Intern Med. 1997; 127: 1109-1123Crossref PubMed Scopus (201) Google Scholar It would be prudent to treat for suspected neuroborreliosis, even if cause and effect cannot be established unequivocally,5Halperin JJ Logigian EL Finkel MF Pearl RA Practice parameters for the diagnosis of patients with nervous system Lyme borreliosis (Lyme disease).Neurology. 1996; 46: 619-627Crossref PubMed Scopus (161) Google Scholar although disorders can be misdiagnosed as neuroborreliosis which can lead to undertreatment of the underlying disease. A slow response to treatment is common, but a lack of response may indicate an incorrect diagnosis rather than therapy-resistant Lyme disease.3Sigal LH The Lyme disease controversy.Arch Intern Med. 1996; 156: 1493-1500Crossref PubMed Google Scholar Consideration should be given to these issues to avoid unrealistic expectations and unnecessary and possibly harmful treatment. Michael Riedel and colleagues (Feb 7, p 418)1Riedel M Straube A Schwarz MJ Wilske B Muller N Lyme disease presenting as Tourette's syndrome.Lancet. 1998; 351: 418-419Summary Full Text Full Text PDF PubMed Scopus (62) Google Scholar describe a manifestation of neuroborreliosis. Diagnosis of Lyme disease can be difficult and guidelines have been established that involve a two-test protocol: an ELISA followed by IgG, IgM immunoblotting, or both. Although the immunoblot assay is useful in confirming false-positive ELISA results, it is not a perfect test and there is poor interlaboratory reliability.2Still MM Ryan ME Pitfalls in diagnosis of Lyme disease.Postgrad Med. 1997; 102: 65-72PubMed Google Scholar If IgG is detected rather than IgM, it may represent past infection and Borrelia burgdorferi may not be responsible for the current illness. If the pretest probability of disease based on clinical findings is low, then the positive predictive value of tests used will be low.3Sigal LH The Lyme disease controversy.Arch Intern Med. 1996; 156: 1493-1500Crossref PubMed Google Scholar Non-specific symptoms alone, such as headache, fatigue, myalgia, or arthralgia, even in endemic areas will not increase the pretest probability to the levels at which testing is clinically useful (0·20–0·80 probability).4Tugwell P Dennis DT Weinstein A et al.Laboratory evaluation in the diagnosis of Lyme disease.Ann Intern Med. 1997; 127: 1109-1123Crossref PubMed Scopus (201) Google Scholar There are insufficient data to evaluate strategies for patients with rare manifestations such as neuro-ophthalmological disorders, and two-step testing is recommended.4Tugwell P Dennis DT Weinstein A et al.Laboratory evaluation in the diagnosis of Lyme disease.Ann Intern Med. 1997; 127: 1109-1123Crossref PubMed Scopus (201) Google Scholar It would be prudent to treat for suspected neuroborreliosis, even if cause and effect cannot be established unequivocally,5Halperin JJ Logigian EL Finkel MF Pearl RA Practice parameters for the diagnosis of patients with nervous system Lyme borreliosis (Lyme disease).Neurology. 1996; 46: 619-627Crossref PubMed Scopus (161) Google Scholar although disorders can be misdiagnosed as neuroborreliosis which can lead to undertreatment of the underlying disease. A slow response to treatment is common, but a lack of response may indicate an incorrect diagnosis rather than therapy-resistant Lyme disease.3Sigal LH The Lyme disease controversy.Arch Intern Med. 1996; 156: 1493-1500Crossref PubMed Google Scholar Consideration should be given to these issues to avoid unrealistic expectations and unnecessary and possibly harmful treatment.