Later signs and symptoms. If untreated, new signs and symptoms of Lyme infection might appear in the following weeks to months. These include: 1  Erythema migrans appearing in other areas of your body. 2  Joint pain.3  Bouts of severe joint pain and swelling are especially likely to affect your knees, but the pain can shift from one joint to another.ater signs and symptoms. If untreated, new signs and symptoms of Lyme infection might appear in the following weeks to months. These include: 1  Erythema migrans appearing in other areas of your body. 2  Joint pain.