System	Stage 1 (early localized)	Stage 2 (early disseminated)	Stage 3 (late chronic)
Cardiac	—	Atrioventricular block; myopericarditis; pancarditis	—
Constitutional	Influenza-like symptoms	Malaise; fatigue	Fatigue
Lymphatic	Regional lymphadenopathy	Regional or generalized lymphadenopathy	—
Musculoskeletal	Myalgia	Migratory pain in joints, bone, muscle; brief arthritis attacks	Prolonged arthritis attacks; chronic arthritis
Neurologic	Headache	Meningitis, Bell’s palsy; cranial neuritis; radiculoneuritis	Encephalopathy; polyneuropathy; leukoencephalitis
Skin	Erythema migrans	Secondary annular lesions	Lymphocytoma; acrodermatitis chronica atrophicans