This is the time of the year that we begin to find ticks on our clothing or pets and sometimes attached to our skin after we have been in fields and woods or clearing garden plots and fences.
Tick bites can transmit a variety of infectious diseases, but this article will cover Lyme disease only. The highest incidence of Lyme disease (LD) is in Pennsylvania, New York, New Jersey, Connecticut, Rhode Island, Massachusetts, Wisconsin and Minnesota.
Adult stages of the deer ticks (Ixodesscapularis and Ixodespacificus) are the primary insects that spread Lyme disease. The tick transmits the spirochete Borreliaburgdorfer during its feeding phase. Although a person may be bitten by an infected tick, the chance of transmission is very small unless the tick has been embedded for at least 36 hours.
Stages of Lyme disease
Lyme disease can present itself in various ways depending on how long a person has been infected. Below are brief descriptions of these stages:
Erythema migrans (EM) is the only presentation in which the diagnosis of Lyme disease can be made without laboratory testing. EM occurs in three to 32 days after an infected tick bite. Its starts as a red pimple at the bite site spreading out to a rash that resembles a bulls-eye. Because ticks will seek out dark, moist areas to embed, such as the groin, high inner thigh or armpit, the rash may not always visible. Only about 50-70% of infected people present this way to the doctor.
General symptoms, such as fatigue, generalized aching, or lymph node enlargement may precede, be accompanied by or followed by the development of a rash. EM will quickly disappear without treatment so that if the person does not notice the rash and does not have systemic symptoms, they may not be aware of the exposure. (Only 30% of people who get Lyme disease recall a tick bite.)
Early disseminated Lyme disease
If a person develops multiple organ system disease, aggressive antibiotic treatment is needed to prevent cardiac, rheumatologic or neurological conditions that can develop several months after being infected. Cardiac conduction defects are rare. Hospitalization is required for cardiac monitoring before initiating intravenous antibiotic treatment. Early reversible neurological conditions include painful radiculopathies, meningitis, encephalopathy and facial paralysis. These conditions can occur in up to 15% of untreated patients.
Late Lyme disease
There are a variety of musculoskeletal conditions that develop in the late stage of LD, including multiple joint pain, tendonitis, bursitis and fibromyalgia. Lyme disease is easily confused with chronic fatigue syndrome. Because of similarity of symptoms, treatment can be significantly delayed if LD is not diagnosed early. The arthritis of LD involves multiple joints. If the infection is long standing, symptoms may not resolve even with appropriate antibiotic treatment.
Diagnosis of Lyme disease
Most Lyme infections are diagnosed because the doctor or person thinks they may be at risk and requests lab testing. In practice, it is not common to see a bulls-eye lesion; more commonly the person is tested when experiencing fatigue, joint aching or presents with a nerve condition such as Bell’s palsy. Many infections are picked up because of periodic screening if the person lives or works in high-risk areas but has no symptoms.
Diagnosing Lyme disease requires a two-part lab test. The first part is an antibody screen known as ELISA. If positive or equivocal, the same serum specimen is retested by test known as a Western Blot.
A negative response at six to eight weeks post-tick exposure generally indicates no active infection. However, if the test is performed too early (four to six weeks), there may be inadequate antibody response at that point in time. Another important reason is that if the person took an antibiotic for another reason during this six-week incubation period, there will be a delay in developing a positive response.
A positive ELISA (but negative Western Blot) may also occur because of antibody cross-reactions to similar antibodies from other infections. Another test available is the Polymerase chain reaction (PCR) test that may be used to identify an active infection if you have symptoms that have not gotten better with antibiotic treatment. PCR testing is not done as a first test because it requires technical skill, is expensive and associated with false positive results.
Current antibiotic treatment recommendation
The treatment of new Lyme infections consists of antibiotic treatment. Oral doxycycline for 14 to 21 days is the drug of choice. Other oral antibiotics can be prescribed if you are allergic or have side effects from doxycycline. People with cardiac, reoccurring joint arthritis or neurologic complications, may require intravenous antibiotics.
Lyme disease vaccine is no longer offered because its protection is not long- lasting.
First Aid and Prevention
• If you find a tick in clothing or on the skin, but not attached, the chance of Lyme disease is very small. Finding unattached ticks do not need testing, but monitor yourself or your child for rashes or flu-like symptoms.
• Attached ticks should be promptly removed with forceps or fine tweezers. The head of the tick should be grasped as close to the skin as possible and pulled gently from the skin, using a twisting motion. After as much of the tick has been removed as possible, the bite should be disinfected and covered. Do not use nail polish, petrolatum or hot matches to remove the tick. Call your physician for recommendations about follow up. If you develop a rash or flu-like symptoms within 30 days of removing a tick, see your doctor as soon as possible.
• Prevention is the most important thing you can do to avoid tick exposure. Anticipate ticks if you are going to be in moist, wooded or grassy areas. Walk in the center of trails. Wear long sleeves and pants. If possible tuck in pant legs into boots or long stockings. You can use spray products containing permethrin on boots, clothing and camp gear, but avoid skin exposure with these sprays.
• Recommendations by the CDC include the use of a repellent with DEET on skin. Repellents containing 20% or more DEET (N, N-diethyl-m-toluamide) can protect up to several hours. Always follow product instructions. For detailed information about using DEET on children, see recommendations from the American Academy of Pediatrics.
• Shower as soon as possible after you come indoors. Showering will help remove unattached ticks. Always check under the arms, in and around the ears, inside belly button, back of the knees, in and around the hair, between the legs and around the waist on yourself or your child.