Symptoms, Disagnosis and Treatment

Early Lyme Disease

The early stage of Lyme disease is usually marked by one or more of the following symptoms and signs:

Fatigue
Chills and fever
Headache
Muscle and joint pain
Swollen lymph nodes
a characteristic shin rash called erythema migrans

Erythema migrans is a red circular patch that appears usually 3 days to 1 month after the bite of an infected tick at the site of the bite. The patch then expands, often to a large size. Sometimes many patches appear, varying in shape, depending on their location. Common sites are the thigh, groin, trunk, and the armpits. The center of the rash may clear as it enlarges, resulting in a bulls-eye appearance. The rash may be warm, but it usually is not painful. Not all rashes that occur at the site of a tick bite are due to Lyme disease, however. For example, an allergic reaction to tick saliva often occurs at the site of a tick bite. The resulting rash can be confused with the rash of Lyme disease. Allergic reactions to tick saliva usually occur within hours to a few days after the tick bite, usually do not expand, and disappear within a few days.

Lyme Disease Rash

Examples of erythema migrans

Late Lyme Disease

Some symptoms and signs of Lyme disease may not appear until weeks, months, or years after a tick bite:

Arthritis is most likely to appear as brief bouts of pain and swelling, usually in one or more large joints, especially the knees.
Nervous system abnormalities can include numbness, pain, Bell's palsy (paralysis of the facial muscles, usually on one side), and meningitis (fever, stiff neck, and severe headache).
Less frequently, irregularities of the heart rhythm occur.
In some persons the rash never forms; in some, the first and only sign of Lyme disease is arthritis, and in others, nervous system problems are the only evidence of Lyme disease.

Late Disease and Pregnancy

In rare cases, Lyme disease acquired during pregnancy may lead to infection of the fetus and possibly to stillbirth, but adverse effects to the fetus have not been conclusively documented. The Centers for Disease Control and Prevention (CDC) maintains a registry of pregnant women with Lyme disease to advance the understanding of the effects of Lyme disease on the developing fetus.

Diagnosis

Lyme disease is often difficult to diagnose because its symptoms and signs mimic those of many other diseases. The fever, muscle aches, and fatigue of Lyme disease can easily be mistaken for viral infections, such as influenza or infectious mononucleosis. Joint pain can be mistaken for other types of arthritis, such as rheumatoid arthritis, and neurologic signs can mimic those caused by other conditions, such as multiple sclerosis. At the same time, other types of arthritis or neurologic diseases can be misdiagnosed as Lyme disease.

Diagnosis of Lyme disease should take into account:

History of possible exposure to ticks, especially in areas where Lyme disease is known to occur.
Symptoms and signs.
The results of blood tests used to determine whether the patient has antibodies to Lyme disease bacteria

These tests are most useful in later stages of illness, but even then they may give inaccurate results. Laboratory tests for Lyme disease have not yet been standardized nationally.

Treatment and Prognosis

Lyme disease is treated with antibiotics under the supervision of a physician. Several antibiotics are effective. Antibiotics usually are given by mouth but may be given intravenously in more severe cases. Patients treated in the early stages with antibiotics usually recover rapidly and completely. Most patients who are treated in later stages of the disease also respond well to antibiotics. In a few patients who are treated for Lyme disease, symptoms of persisting infection may continue or recur, making additional antibiotic treatment necessary. Varying degrees of permanent damage to joints or the nervous system can develop in patients with late chronic Lyme disease. Typically these are patients in whom Lyme disease was unrecognized in the early stages or for whom the initial treatment was unsuccessful. Rare deaths from Lyme disease have been reported.

Preventive Antibiotic Treatment

Antibiotic treatment to prevent Lyme disease after a known tick bite may not be warranted. Physicians must determine whether the advantages of using antibiotics outweigh the disadvantages in any particular instance. If antibiotics are not used, physicians should alert patients to the symptoms of early Lyme disease and advise them to return for reevaluation if symptoms occur.Recent studies on the prophylactic value of single-dose doxycycline for the prevention of Lyme disease indicate that a 200-mg dose administered within 72 hours of tick removal can prevent disease in 87% of test subjects. (Original article) However, it is worth noting that several prior controlled treatment trials found no benefit in prophylaxis.