In the tick's larvae stage, it is tan, the size of a pinhead, and feeds on small animals like mice. During the nymph stage, the tick is the size of a poppy seed, beige or partially transparent, and feeds on larger animals such as cats, dogs, and humans. The skin rash is a red circular patch about 2 inches in diameter that appears and expands around the site of the tick bite. The rash may be warm, but it usually is not painful or itchy. Some infected people do not recognize the early symptoms and are diagnosed only after complications occur.
Early symptoms can develop within a week to a few weeks of the tick bite.
Other symptoms can appear weeks, months, or years later. Lyme disease is diagnosed by a physical examination and medical history. The clinical diagnosis is supported by laboratory testing. Diagnosis of Lyme disease can be difficult. Current tests are not completely accurate, and the symptoms can mimic those of other diseases.