What Makes Lyme Disease Tick

Bad pun nothwithstanding, here's what you need to know

After a winter spent indoors, many of us look forward to the warmth of spring and summer, and the opportunity to spend time with nature. Along with the flowers of spring, animals that have hidden during the cold months reappear.

One emerging creature that is best avoided is the black-legged (formerly deer) tick, which transmits Lyme disease. Rare in the winter months, Lyme disease becomes more common in May, June, and July. Your state's Cooperative Extension Service can help you pinpoint Lyme disease season in your geographic area.

What it is

Lyme disease gets its name from an outbreak of an arthritis-like disease that occurred in Old Lyme, Connecticut. The disease was known long before it was named in 1977; according to the Lyme Disease Foundation, the symptoms of Lyme disease were first described in 1883.

Outbreaks of Lyme disease have been identified throughout the US, though most cases occur in the Northeast. Lyme disease is caused by a bacterium, Borrelia burgdorferi, that is carried by certain tick species. In the eastern US, the bacterium is found in black-legged ticks (Ixodes scapularis); in the western US, the western black-legged tick (Ixodes pacificus) is the usual carrier. Both ticks are tiny; a young tick is about the size of a pin head, and mature ticks are about 1/4 inch long.

The Borrelia bacterium is transmitted from a tick to a human when the tick bites through the victim's skin to feed. Ixodes bites are often painless, and the ticks are small enough to feed unnoticed by their victim, dropping off when they finish their meal. Many people who contract Lyme disease don't remember being bitten.

Ticks that transmit Lyme disease normally prey on deer and rodents, but they will feed on humans, given the opportunity. A tick must be attached to a human for 24-48 hours to transmit Lyme disease.

What it looks and acts like

A red rash at the site of the tick bite is one of the first signs of Lyme disease, though not everyone develops this symptom. The rash usually begins a week after the bite, and appears on the thigh, groin, trunk, or armpits.

Within days or weeks, the rash grows from a small, red bump into a larger circular area that may have a bulls-eye pattern. An infected person may have a headache and flu-like symptoms, as well.

If the infection is left untreated for several months, the Borrelia bacterium can affect the nervous system, causing temporary facial paralysis (Bell's Palsy), stiff neck, meningitis, numbness, and loss of motor coordination. Other symptoms include irregular heartbeat, severe fatigue, and numbness. During later stages of the disease, swollen joints (often the knees) and intermittent of chronic arthritis may develop.

How it's diagnosed

People who are diagnosed and treated early for Lyme disease have the best prognosis. A lab test can detect antibodies to Borrelia in an infected person's blood, but this test isn't accurate during early stages of infection. For this reason, most cases are diagnosed based on the patient's physical symptoms, and likelihood of exposure to infected ticks.

How it's treated

Antibiotics are used to treat Lyme disease. The choice of antibiotic depends on the disease stage and the patient's symptoms. Oral amoxicillin or doxycycline may be used during the early stages of infection, when the patient exhibits a rash but no neurological symptoms.

Early treatment with oral antibiotics can prevent Lyme disease from causing neurological or arthritis symptoms. Once neurological symptoms appear, ceftriaxone can be administered intravenously each day for up to a month. Lyme disease is completely curable if it is treated early. Delaying treatment can cause permanent damage to joints, leading to chronic arthritis.

How to prevent it

Should you stay indoors all spring and summer to avoid ticks? No, but there are sensible precautions that you can take to avoid getting Lyme disease.

In certain regions, up to half of all susceptible deer ticks carry the Borrelia bacterium, but overall, about one in 100 black-legged ticks are Lyme carriers. Ixodes ticks are common in woody and shaded grassy areas. If you see deer and rodents in your backyard, you may also have ticks.

Ticks don't fly or pounce on their victims--they sit on vegetation and wait for a host animal (or human) to brush against them. Clearing brush and mowing regularly can help eliminate tick habitats and reduce your chances of exposure to Lyme-carrying ticks. When walking in wooded areas, stay in the center of a cleared trail to avoid touching tick-infested plants.

Wearing pants and long sleeves in July can be uncomfortable if you live in a warm climate, but clothing is a good barrier between ticks and your skin. Ticks are easier to spot on light colored clothing than on dark.

Insect repellants with DEET help keep ticks away, but should be used with caution. DEET can cause unpleasant side effects, especially in children, when it is used on the skin. Permethrin will kill ticks on contact, but should only be used on clothing, not skin.

Other pesticides can be sprayed on brush to kill ticks. Always follow the manufacturer's instructions when using pesticides or insect repellants.

When tick season starts, always check your clothing, skin, and hair for ticks when you come indoors. Remember that immature ticks are tiny, and may be mistaken for dirt or freckles, so a thorough look is needed to spot them. And don't forget the dog, since ticks will attach to pets as well as humans. The Borrelia bacterium can make dogs ill, if the infected tick isn't removed. Undetected ticks can also be transferred from dogs to humans.

What should you do if you discover a tick attached to your skin? Don't panic, and don't try to burn, smother, or squeeze the tick.

Instead, use tweezers to gently grasp the tick's head and pull the tick from the skin. Place the tick in a container so that it can be identified, then disinfect the bite and call your health care provider.

Vaccination?

In 1998, the Food and Drug Administration approved the first Lyme disease vaccine. But the vaccine is approved only for adults 17-70 years old. Since the vaccine is new, it's not know how long protective immunity lasts after vaccination. So for now, avoiding ticks and getting prompt treatment for tick bites are the most dependable ways to avoid contracting Lyme disease.

Kate Traynor is a fabulous medical babe, writer, and mother to two little boys.

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