Lyme Disease

Time to walk the dog. Hot and humid conditions but I don a long sleeve shirt treated with insect repellent and long white pants. I tuck the cuffs of the pants into heavy white socks. Why? Ticks!

Deer ticks of the genus Ixodes may transmit Lyme disease with a bite. A spirochete (spiral shaped bacterium), Borrelia burgdorferi is the causative organism. The tiny deer tick must be attached for at 36 hours before transmitting the pathogen. In the ER a single dose of antibiotic may be given if the tick bitten patient meets certain criteria. Most important is that the tick is identified as a deer tick and not the more common dog tick. The deer tick must have been attached for at least 36 hours and the antibiotics be given with 72 hours of removing the tick. The preferred antibiotic is doxycycline. For children, women who are pregnant or breast feeding, or those patients allergic to tetracycline, another antibiotic will be used.

Early Lyme disease is characterized by flulike symptoms. The patient often has chills, a low grade fever, headache, muscle aches, tiredness, joint aches, and less frequently nausea and vomiting. These symptoms appear within 30 days of the initial bite. A characteristic rash, erythema migrans (EM), occurs in 80% of Lyme disease patients, on average 7-10 days post bite. It is flat and red and spreads out from the center. 40% of the cases of erythema migrans show clearing of the redness staring in the center and moving to the edges. 20% of patients with EM will have separate lesions, thought to be from spread of the bacteria via the blood stream.

Stage 2 Lyme disease is also referred to early disseminated. Neurological, joint and cardiac manifestations of Lyme disease are present. Cardiac problems occur in less than 10% of stage 2 and 3 Lyme patients. Palpitations, syncope (sudden loss of consciousness) and chest pains are the symptoms of borrelia infection of the heart. Damage to the conducting cells in the heart may lead to dangerously slow heart rates. Infection with inflammation of the heart muscle and/or the membrane covering the heart chest pain from myocarditis or pericarditis respectively.

Joint pains or arthralgias are common in both stage 1 and 2 of Lyme disease. Actual inflammation of the joints, arthritis is more commonly seen in stage 3. Bursitis, myositis, sinovitis, and tendonitis causes pains of muscles, tendons and bursae.

Infection of the cornea or uvea of the eye may lead to eye pain and visual changes in some Lyme patients.

Stage 2 disease occurs weeks to months after the initial bite. The neuropsychiatric symptoms of stage 2 Lyme are varied and mimic other diseases. Decreased concentration, memory disorders, numbness, nerve pains, sleep disorders, paralysis of facial muscles and visual changes have all been reported. 25% of Lyme patients with a facial palsy will have the condition on both sides of the face. Headache and neck pain and stiffness are symptoms of Lyme meningitis.

Other signs of Lyme disease may include an enlarged liver or spleen and enlarged lymph nodes. Blood tests starting with the ELISA for Lyme will be sent. A Western Blot test may be used to confirm the diagnosis. A lumbar puncture will be done if there are signs of meningitis or neurological symptoms of Lyme disease.

Stage 3 Lyme disease, or tertiary Lyme occurs months to years after the initial bite. This may happen because the initial disease wasn't treated at all or inadequately. There is some experimental evidence that the spirochete may persist intracellularly in fibroblasts despite adequate antibiotic treatment. Arthritis of the knees and other large joints is evident in tertiary Lyme. Cardiac symptoms as noted earlier are also occasionally found in stage 3. Fatigue, chronic headaches, memory loss, sleep disorders, abnormal sensitivity to light, confusion, decreased levels of consciousness and numbness and tingling are all neurological signs of tertiary Lyme disease.

Chronic Lyme disease is reported by some patients. This may represent an autoimmune phenomenon. Molecular mimicry occurs when one's immune system attacks one's body because of similarity to molecular components of the Borrelia spirochete. Some physician treat chronic Lyme patients with antibiotics for many months to years. There is no experimental proof that this treatment is effective.

As with many of life's unpleasant diseases, prevention is the best weapon. Risks of exposure to deer ticks are gardening, hiking, hunting, walking in high grass and pet ownership. My bizarre attire when dog walking is just what is recommended. Long sleeves and pants. Insect repellent sprays. Light colored clothes to more easily spot the tiny ticks. Use of tick and flea treatments for outdoor pets is also a good idea. There is a veterinary vaccine for Lyme but its effectiveness is questionable. Have a great summer.