The dangerous disease carried by deer ticks.
By Marven Ewen, MD
It’s that time of year again. When the weather warms up the ticks come out. The ticks we are mostly concerned about are deer ticks. Deer ticks (Ixodes scapularis) carry Lyme disease. Lyme disease in the USA is caused by a bacterial parasite called Borrelia burgdorferi.
The life cycle of this parasite is interesting in that it is picked up by deer ticks in their larval stage from small rodents. The larva then goes on to spread it to other rodents. When the larva develops into the adult tick, it then begins to attach to larger mammals to feed and transmit the parasite. In humans, it causes a disease known as Lyme disease.
Deer ticks, which are also called Black Legged ticks, are much smaller than common dog (wood) ticks. Although wood ticks can carry and transmit other diseases, they are not a vector for Lyme disease.
Even though deer ticks are known to carry B Burgdorferi, not all ticks are infected. Approximately 20% or so carry the disease, but this varies somewhat by region of the country. Furthermore, a minimum of 24 hours are required for transmission of the parasite to the human host after a tick attaches. More commonly, it takes 36 hours or more for transmission of the parasite.
Lyme disease symptoms start after 3 days, but not more than 30 days. Initially, it may start with fever, myalgias, fatigue, headaches, achy joints, and swollen lymph nodes. About 80% of patients will also get a migrating expanding rash known as Erythema Migrans. This is a unique rash that may resemble a bullseye.
It starts with redness at the area of the bite and then expands, leaving a clear center, hence the bullseye description. This type of expanding rash can later appear on other areas of the body as well.
If not recognized and treated in the first stage, it goes on to cause further and more severe symptoms over time. These symptoms can develop within days to months after the initial stage, including swollen painful joints, severe headaches, nerve problems like shooting pains in limbs or numbness or Bell’s Palsy (unilateral facial paralysis), memory problems, heart problems (carditis).
Unfortunately, many of these symptoms can be caused by other diseases also, which can result in a delayed diagnosis. It is important that patients with any of these symptoms be tested for Lyme disease by a blood test.
So what to do if you find a tick imbedded on your body? First, don’t panic. Most deer tick bites don’t result in Lyme disease. Use a tick remover: a small inexpensive curved piece of metal with a slit that is placed under the body of the tick, then gently pull off the tick. These are available in recreation equipment stores and some drug stores. You should have one available just in case.
You do not want to squeeze the tick or try to kill it with a hot match. That will just cause it to regurgitate into your body, making transmission of infection more likely. Also note that if the head remains imbedded in the skin, this is nothing to be concerned about; as the skin sheds over time the remains will fall out.
Watch for a rash or flu like symptoms especially if the tick has been present for 24 hours or more. If you develop any of the symptoms noted before, see your physician.
More from The Allied Times
Close Encounter with a BatA cautionary tale about the risk of rabies.By Marven Ewen, MDMedical DirectorOne day while walking through a big box store, a customer was struck on the head by a flying bat (the mammal, not the wooden kind). He was concerned he might have contracted rabies from this contact and came to…
MelanomaThe most serious form of skin cancer.By Jenny Ewen, BA, NREMTEditor-In-ChiefOverviewEver been worried about a new mole or discoloration appearing on your skin? Welcome to melanoma, the most serious form of skin cancer, which is increasing in people under 40. Almost 200,000 new cases of melanoma are estimated to be diagnosed in America this year…
Lyme DiseaseThe dangerous disease carried by deer ticks.By Marven Ewen, MDMedical DirectorIt’s that time of year again. When the weather warms up the ticks come out. The ticks we are mostly concerned about are deer ticks. Deer ticks (Ixodes scapularis) carry Lyme disease. Lyme disease in the USA is caused by a bacterial parasite called…
Spina BifidaThe result of a neural tube defect.By Jenny Ewen, BA, NREMTEditor-In-ChiefOverviewSpina bifida is the most common birth defect in the United States that results in permanent disability – the literal meaning of the name is “Split spine” and occurs during the first 28 days of pregnancy. It is a neural tube defect, and the…
Lightning StrikesInjury patterns caused by bolts of lightning.By Marven Ewen, MDMedical DirectorYour general risk of being struck by lightning is about 1/700,000 per year. About 10% of strikes result in death. Of course, that risk can go way up or down depending on a person’s behavior. The specific lightning we are concerned with is generated by…
Nursemaid’s ElbowA common pediatric injury.By Marven Ewen, MDMedical DirectorOne of the most common pediatric injuries is nursemaid’s elbow. I have seen many of these in my career. The usual mechanism of injury is a sudden pulling on the child’s forearm or wrist, such as when a parent pulls a child away from traffic or some…