DEAR DR. GOTT: My daughter recently had a rash on her right rib area following a tick bite that may have been unrelated. We live in the Northeast section of the country where deer ticks are prevalent. The rash didn’t look like one from Lyme disease and we thought it was hives but her doctor did blood work and she was found to have ehrlichiosis. What on earth is this?
DEAR READER: Ehrlichiosis is a bacterial infection transmitted by the bite of a tick. The disease is carried primarily – but not exclusively – by the the Lone Star tick, but can also be transmitted by deer ticks (which are also known to transmit Lyme disease) and dog ticks. Symptoms vary from person to person but will resemble those of the flu. Although the CDC does report sporadic influenza infections all year, in non-endemic months the chances of infection are exceedingly rare so in my opinion, if your daughter had symptoms during the spring or early summer, she shouldn’t attribute them to the flu.
Some people with ehrlichiosis have extremely mild symptoms and don’t even seek medical assistance, as the body can fight off minor infection on its own without intervention. Others have signs that include muscle aches and pains, fever, headache, vomiting, cough, diarrhea, rash, chills and nausea. Interestingly, a rash appears in fewer than half of all cases which makes it somewhat difficult to diagnose without laboratory testing.
A tick latches onto a host, feeding until it swells to many times its normal size. Bacteria enters the skin and ultimately the bloodstream through the tick’s bite. Infection can also occur through blood transfusions or direct contact with a slaughtered animal that is infected. While controversy abounds, the commonly held belief is that a tick carrying the bacterium can only rarely transmit the disease unless it has fed on a person for at least 24 hours. This is opposed to some health care professionals’ opinions who feel a tick only has to attach to the skin for transmission to occur. Symptoms generally appear between 7 and 14 days from the time a bite occurs. This is known as the incubation period. Individuals with a compromised immune system are at a higher risk for infection.
Treatment is with antibiotics, commonly either doxycycline or tetracycline. Because I do not know how old your daughter is, I must state that children should not take tetracycline orally until after all their second teeth have grown in because the drug can permanently change their color. Doxycycline used for two weeks or less will not usually discolor the teeth.
Diagnosis is made through the medical history presented to a physician as well as laboratory testing. If blood work is done, it will classically reveal a low white blood cell count, abnormal liver functions and a low platelet count. Some facilities have the capability of doing an IFA test, (indirect fluorescent antibody) test that measures the amount of antibody in the blood to the bacteria that causes ehrlichiosis or a PRC (polymerase chain reaction) test that identifies certain genes unique to the disease. Some hospitals also offer a direct microscopic test in which laboratory technicians look for the intracellular bacteria in a blood smear.
On the home front, prevention is the name of the game. If you are in an endemic area, wear long pants and sleeves when going out-of-doors. Tuck your pant legs into your socks and your shirts in at the waist. Avoid flip-flops or open-toed shoes. Spray your shoes with a product containing DEET. Stay out of high grasses and wooded areas when possible. Do a complete body check when you get home. If you find a tick on you, use tweezers to remove it, as the tick’s saliva and bodily fluids can transmit bacterium from their mouth that can enter your body through a cut, scrape or break in your skin. Don’t yank on the tick but pull it upward firmly with the tweezers by its mouth parts that have attached to the skin. Kill the tick by either putting it in an alcohol solution or by my favorite method of sticking it to a piece of transparent tape that can be folded over, encasing and disabling the critter. Do not attempt to kill the tick by crushing it in your fingers, again because of the possibility of bacterial transmission. Clean the bite site and monitor it as well as the rest of your body for a period of time to assure there are no tell-tell tale signs of ehrlichiosis. This is important because while a tick may have attached to your mid-section, you could have a rash or skin lesions anywhere on your body. Then remember Rover or the cat. If your animals accompany you on walks, give them a once-over also. Animals often walk in the grass and can easily transmit unwanted critters into your home.
