Lyme disease usually occurs in 3 stages following a tick bite:
Localized (stage 1): present in 86% of infected patients. It is characterized by skin involvement, initially a red macule or papule, which later expands in a circular manner, usually with a bright red border and a central clear indurated area, known as erythema chronicum migrans.
Disseminated (stage 2): can occur within days to weeks. It manifests as a flulike illness with headaches, fatigue, and musculoskeletal aches.
Persistent (stage 3): more profound symptoms occur during this stage, as the infection localizes to the nervous, cardiovascular, and musculoskeletal systems.
Neurologic complications such as meningitis, encephalitis, cranial neuritis (including Bell palsy), radiculopathy, and neuropathy occur in 10%–15% of patients.
Late persistent manifestations are usually confined to the nervous system, skin, and joints. Late neurologic signs include encephalomyelitis as well as demyelinating and psychiatric syndromes. Joint involvement includes asymmetric pauciarticular arthritis; skin involvement is characterized by acrodermatitis chronica atrophicans or localized lesions resembling those of systemic sclerosis.
Other systemic manifestations during the initial dissemination or the late persistent state include uveitis, conjunctivitis, keratitis, neuritis, lymphadenopathy, orbital myositis, hematuria, and orchitis. In some studies, serologic testing of patients with chronic fatigue syndrome has shown an increased incidence of positive results for B burgdorferi antibodies.
Excerpted from BCSC 2020-2021 series: Section 1 - Update on General Medicine. For more information and to purchase the entire series, please visit https://www.aao.org/bcsc.