Symptoms alone are not enough reason to test a patient for Lyme disease, and not every patient with Lyme disease will present with target lesions, according to a presentation at the 2016 Infectious Diseases in Children Symposium.
About 80% to 90% of patients with Lyme disease have the characteristic rash erythema migrans, Eugene D. Shapiro, MD, professor of pediatrics, epidemiology and associate chair for clinical translational and educational research at Yale School of Public Health, told Infectious Diseases in Children. However, the rashes can appear differently; localized diseases in which the erythema appears in a single patch at the affected site accounts for 60% to 70% of clinical manifestations of Lyme, and disseminated disease — an appearance of multiple erythema on the skin — accounts for 20% to 25% of cases.
“Erythema migrans rashes in the United States most often do not appear as bullseyes, rather, only about a third of them do,” Shapiro said in the presentation. “About two-thirds [of rashes] are largely erythematous, so do not think a patient must have a bullseye rash for it to be erythema migrans.”
Further, other diagnoses of erythema migrans include nummular eczema, ringworm, cellulitis, granuloma annulare, arachnid or other insect bite and erythema multiforme. Many early signs and symptoms present before testing are similar to these diagnoses; however, early disseminated disease accounts for 25% of early Lyme cases, multiple erythema migrans for 20%, neurologic, including cranial nerve palsy and meningitis for 5%, and carditis and syncope for less than 1% of early clinical manifestations. Knee arthritis is indicative of late disseminated disease in 7% of Lyme diagnoses.
Shapiro further noted there are no symptoms on their own that should give a pediatrician reason to test for positive results. Most patients who present with myalgia, arthralgia, headache and fatigue may have similar symptoms related to Lyme, but often have a separate underlying illness.
“Because most symptoms are accompanied by subjective signs, to test patients who have only those symptoms without objective signs such as nerve palsy, frank arthritis and so on, the vast majority of the test results are going to be false positive results,” Shapiro said. “That is the reason there is this myth that chronic Lyme disease is common and difficult to treat. Such patients do not have Lyme disease in the overwhelming majority of cases.”
Teaching physicians unfamiliar with Lyme to manage medically unexplained symptoms without diagnosing an illness proves challenging, Shapiro said.
“It is important to integrate psychological and biological factors associated with fatigue and anxiety when managing symptoms without a diagnosis in a patient who may have a ‘chronic’ disease,” he said.