Brush Up on Tick Bites and Preventing Lyme Disease

Top Takeaways

• Gather details about the tick bite, including when and where it happened and how long it was attached.
• Recommend doxycycline prophylaxis if a tick was attached for more than 24 hours and occurred within the previous 72 hours in a high-risk area.
• Advise all patients with a recent tick bite to watch for Lyme disease symptoms (e.g., ring-like rash, flu-like illness).

It’s that time of year to stay alert for tick bites and know when to prescribe antibiotics for preventing Lyme disease.

Follow a stepwise approach when evaluating a tick bite.

Assessment. Gather relevant information, such as when the bite occurred and how long it was attached. Educate patients on how to safely remove the tick if it’s still attached.

Use eTick or TickEncounter to help identify the tick species. Only black-legged ticks are at risk of carrying Borrelia burgdorferi, the bacteria that cause Lyme disease.

Consider whether the tick bite occurred in a high-risk area (Halifax, Ottawa, Victoria, etc).

Antibiotic prophylaxis. Prescribe or recommend antibiotic prophylaxis for a tick attached more than 24 hours and that occurred within the previous 72 hours in a high-risk area.

Give a single dose of doxycycline... 200 mg for adults or 4 mg/kg for kids, up to 200 mg.

For tick bites older than 72 hours, rely on “watchful waiting” for 30 days...since data are lacking about antibiotic benefit.

Counsel all patients to watch for a ring-like rash, with or without a bull’s-eye...or a flu-like illness (fever, chills, headache, etc).

Refer these patients to their prescriber for a treatment course of antibiotics, if needed. But reassure that the risk of developing Lyme disease after a bite from an infected tick is low...between 1% to 3%.

Prevention. Continue to emphasize prevention...wearing protective clothing, using tick repellent, and checking for ticks after being outdoors in a wooded or grassy area.

In general, steer patients toward products with DEET 20% to 30% (OFF! Deep Woods, etc) or icaridin (Care Plus, etc).

See our resource, Treatment of Lyme Disease, to find regimens for Lyme carditis, facial palsy, and other complications...and to assess patients efficiently.

• Chart: Treatment of Lyme Disease