Lyme Disease and Related Tick-Borne Infections

Description

Alternative Names

Diseases with Similar Symptoms

Various features of Lyme disease can be mimicked by many other illnesses. Depending on the symptoms, a doctor may be able to perform the evaluations necessary to rule out other conditions.

Ruling Out Other Tick-Borne or Spirochete Infections

Other infections can produce fever, headache, muscle aches, fatigue, and some of the neurologic or cardiac features of early Lyme disease. Some are transmitted by the same tick as Lyme disease.

Co-Infections Transmitted by the Ixodes Tick. Babesiosis and human granulocytic ehrlichiosis (HGE) are transmitted by the same tick that carries Lyme disease. People are often coinfected with one or more of these infections, which can all cause flu-like symptoms. If these symptoms persist and there is no rash, it is less likely that Lyme disease is present. Still diagnosing a coinfection is difficult.

Other Spirochete Infections. Leptospirosis is a spirochete infection spread through animals or contaminated water that most often affects young people during the summer or fall.

Other Tick-Borne Infections. A number of other tick-borne diseases may resemble Lyme disease, although they are more prevalent in other parts of the country.

• Tick-borne relapsing fever, a flu-like illness that occurs in mountainous areas of the West during the summer, may be under-reported and misdiagnosed as Lyme disease.
• Rocky Mountain spotted fever, which is also transmitted by ticks, is most prevalent in the Mid-Atlantic States.
• A tick-borne infection carried by the Lone-Star tick strongly resembles Lyme disease, including a similar rash. It is not caused by the Lyme spirochete, however, and has been identified in patients who live in the southern United States.

Researchers speculate that ticks may be responsible for other diseases not previously thought to be carried by these vectors. For example, the Bartonella family of bacteria causes cat-scratch fever (which is transmitted from cat to cat by fleas) and trench fever (historically transmitted by lice). These bacteria, however, were recently found in an unusually high percentage (20%) of 151 ticks examined in a recent California study, which suggests that these diseases may also be transmitted by ticks. More research is needed to confirm this, however.

Common Rashes

Allergic Reaction to the Tick. If a rash, even ring-shaped, appears hours rather than days after a tick bite, it is most likely an allergic reaction to the tick, not a symptom of Lyme disease.

Other Insect Bites. Not every rash seen in regions where Lyme disease is common is caused by a tick. The bites of many insects and spiders can cause a skin reaction.

Autoimmune Diseases

A number of autoimmune diseases have chronic and low-level symptoms that may be confused with either acute or chronic Lyme disease.

• Systemic lupus erythematosus (SLE) produces a rash (usually on the face), flu-like symptoms, and arthritis, but they usually develop very slowly over time.
• Rheumatoid arthritis or Reiter's syndrome causes pain, swelling, or stiffness of the joints that may be confused with post-Lyme syndrome.
• Scleroderma has a limited form of the disease called morphea, which produces hard patches of skin. Some studies have even reported an association between Borrelia burgdorferi and some cases of morphea. However, the evidence is weak and if it exists it is possibly limited to a specific variant in Europe and Asia. There is no association between severe scleroderma and Lyme disease.
• In children, juvenile rheumatoid arthritis or rheumatic fever, which follows strep throat, should be considered.

Diseases Resembling Post-Lyme Syndrome

A number of conditions cause chronic fatigue and joint and muscle aches that resemble descriptions of post-Lyme syndrome.

• Mononucleosis. This virus infection is common in teenagers.
• Chronic fatigue syndrome (CFS).
• Fibromyalgia.

Depression

Depression that may be mistaken for post-Lyme syndrome is marked by physical symptoms, including persistent fatigue and vague aches and pains.

Meningitis

The early neurologic symptoms of Lyme disease (headache, stiff neck, and fatigue) can easily be mistaken for viral meningitis. Children with viral meningitis are more likely to have a higher fever. Patients with Lyme disease often have other symptoms, such as the bulls-eye rash.