Q: My family is new to the province, and we have been warned of deer ticks when we walk our dog in a nearby wooded area. We were told pharmacists can sometimes write prescriptions for antibiotics after a tick bite. So, our question is at what point does a tick bite require an antibiotic?
Deer ticks are also known as blacklegged ticks. They are one of several species of tick found in New Brunswick and are the only species that carries the bacteria Borrelia burgdorferi that causes Lyme disease. Pharmacists can do assessments and, when appropriate can prescribe prophylactic antibiotics after a tick bite to reduce your risk of developing Lyme disease.
To determine if prophylactic antibiotics are recommended for a tick bite, we need to know where you were in the province when the bite occurred. Each county is assessed as low, moderate or high-risk that the blacklegged ticks are carrying the bacteria. Prophylactic antibiotics are recommended for bites occurring in high-risk areas, as it is estimated that more than 20% of the ticks are carriers.
A map of these areas can be found on the Government of New Brunswick website under the ‘Tick-Borne Diseases’ information section. Peak travel season within our province is about to begin, and it is important to know if you will be spending time in high-risk areas.
We also need to confirm it was a nymph or an adult female blacklegged tick that bit you, as adult males are not carriers. Sometimes we can identify them with clear photos, but it is easier when you bring the tick with you so we can look at the head, back and underbelly.
We then assess how long the tick was attached. Your overall risk of developing Lyme disease after a high-risk bite is approximately 3%, and the tick needs to be attached for more than 24 hours to transmit the bacteria. As ticks feed, they slowly fill with blood and become engorged. If you are unsure how long the tick was attached, we can estimate the attachment time based on the level of engorgement.
When the above criteria are met, it has been less than 72 hours since you removed the tick, and you are not showing any symptoms of Lyme disease, then a single dose of the antibiotic doxycycline is generally recommended.
Prevention will always be our best defense against Lyme disease. When spending time outdoors, be aware that ticks like shaded areas that protect them from drying out, such as wooded areas, tall grass, shrubs and leaf piles. Wearing long socks pulled over your pants and long-sleeved shirts tucked into your pants helps keep ticks on the outside of your clothing. If you wear light coloured clothing, you will be able to see the ticks more easily. You can also apply bug sprays containing DEET or icaridin to help deter ticks.
When you return from outdoors, be sure to tick-check yourself, family members, pets and your gear. Nymphs can be as small as poppy seeds, so take your time checking your scalp, eyebrows, ears, chest, armpits, belly button, lower back, groin, lower buttocks, behind your knees and between your toes. Putting your clothing in the dryer on high heat for 10 minutes will kill any ticks you may have missed.
If you do find a tick attached to your skin, remove it with a pair of fine-tipped tweezers or a tick remover device. Grasp the tick's head as close to your skin as possible and slowly pull upwards with steady, even pressure. Do not twist or crush the tick. Place it in a sealable plastic bag or jar and then clean the area of the bite with soap and water, alcohol, or antiseptic solution.
After all tick bites, you must monitor for early signs of Lyme disease for the next 30 days, even if you take doxycycline. If you develop a rash that may or may not resemble a bullseye but starts at the site of the bite and spreads to be larger than five centimetres over several days or develop flu-like symptoms such as fever, chills, fatigue, swollen lymph nodes, muscle or joint pain see your primary care provider right away.
Erin Thompson (BSc, BScPharm) is a graduate of Dalhousie University and a community pharmacist practicing at Shoppers Drug Mart in Quispamsis N.B. Her opinions expressed in this column are published for educational and informational purposes only, and are not intended as a diagnosis, treatment or as a substitute for professional medical advice, diagnosis or treatment.