Tick season is here—are you ready to counsel with confidence?

A woman approaches the pharmacy counter, looking tired and slightly flushed. “I think I’m having a reaction to something,” she says, lifting her sleeve slightly to reveal a large, reddish patch under her arm. “It wasn’t there a few days ago, and now it’s getting bigger. I also can’t seem to shake this flu - I’ve had headaches and muscle aches for 3 days now since coming back from our trip to Vancouver Island.”As you lean in for a closer look, the shape of the rash catches your attention - a round, expanding circle, with a faint clearing in the middle.“Have you spent any time outdoors recently?” you ask.The woman paused. “We did go hiking near a lake during our trip, but I checked myself for ticks afterwards and I didn’t find anything. Why do you ask?”This brief exchange may sound routine, but it holds the key to early detection of something far more serious: Lyme disease. In many cases, the pharmacist is the first healthcare professional a patient consults; and recognizing subtle signs like this could make all the difference.Lyme disease is endemic in many areas of Canada and the United States, with cases also originating in parts of Europe and Asia. Since Lyme disease became a reportable zoonosis in 2009, case numbers have drastically increased and it is assumed that actual numbers are much higher than we know as many cases are still not reported. In this article we will discuss the mechanism by which Lyme disease is transmitted, the various clinical presentations of Lyme disease, key tips on how to prevent Lyme disease and when to recommend treatment. Tick habitats: identifying high-risk areas for exposureTicks are commonly found in forests, wood piles, tall grass, brush, or under leaves. They do not jump or fly but attach to people or animals who brush past vegetation. The ticks themselves acquire Borrelia burgdorferi, the bacterium that causes Lyme disease, by feeding on infected small mammals such as mice and chipmunks during their larval or nymph stages. Once infected, ticks can transmit B. burgdorferi during feedings and this most commonly occurs during the nymphal stage, when they are incredibly small and difficult to detect. In Canada, blacklegged ticks (Ixodes scapularis) are the primary vector for Borrelia burgdorferi, the bacterium that causes Lyme disease. In North America, transmission occurs primarily through Ixodes scapularis in the east and Ixodes pacificus in the west. In Europe, the main vector is Ixodes ricinus. Nymphal ticks are roughly the size of a poppy seed (1-2mm) and are the most likely to transmit Lyme disease to humans, explaining how even diligent tick checks, like our patient’s post-hike inspection can still miss them.When a tick attaches to a human host, it will often crawl to warm, concealed areas of the body before feeding. Common areas of the body include sites where it finds some sort of resistance, including skin folds, an elastic, the groin, a waistband or even a hairline. The bacteria initially resides in the tick’s midgut and migrates to the salivary glands during feeding, a process that takes anywhere from 36 to 72 hours. As the tick begins to feed on the human host, it eventually begins to secrete the spirochete into its host. Once transmitted into human skin, the bacterium replicates locally, triggering an immune response, and may spread throughout the body over days to months if left untreated.Clinical presentationLyme disease has a wide range of clinical presentations, progressing through early localized, early disseminated, and late stages if untreated. Diagnosis is primarily clinical, keeping in mind that many patients (30–50%) are unaware of a tick or tick bite since the bites are typically painless and again, they tend to bite when they are in their very small, nymphal stages. The most common early sign of infection is often erythema migrans (EM)—a red, expanding skin lesion seen in 70-80% of cases, often accompanied by flu-like symptoms. It’s important to note however, that this means that up to 30% of cases will not present with the typical “bulls-eye” rash. As the infection disseminates, patients may develop flu-like symptoms, fever, multiple EM lesions, neurologic symptoms (e.g., facial nerve palsy, meningitis), cardiac issues such as atrioventricular block, or rarely, ocular inflammation. Notably, children may present atypically, with symptoms like fatigue, anorexia, or even mood changes. Late-stage Lyme disease can appear months after the initial infection and may include Lyme arthritis, typically affecting large joints such as the knees, or even neurologic complications like chronic polyneuropathy. Most of these symptoms resolve with timely treatment, though some patients still experience persistent issues like fatigue or joint pain long after antibiotic treatment. These are considered post-treatment Lyme disease symptoms, and evidence has demonstrated that in spite of possible ongoing symptoms, prolonged antibiotic use is not recommended and has not been effective for symptom resolution. In select cases, co-infections with other tick-borne pathogens may be considered and patients with prolonged ongoing joint symptoms (2 months or longer) despite antibiotic treatment may warrant a referral to a rheumatologist. Post-exposure prophylaxisFor post-exposure prophylaxis of Lyme disease, a single 200 mg dose of doxycycline (or 4 mg/kg for individuals under 45 kg) may be offered within 72 hours of tick removal if three criteria are met: 1) the tick is identified as a blacklegged tick, 2) it was attached for at least 36 hours, and 3) the local infection rate exceeds 20% (where data is available). This strategy significantly reduces infection risk, especially if the tick is visibly engorged. In children under 8 years of age in endemic areas, doxycycline may still be considered, as amoxicillin is not effective in single-dose prophylaxis. Although doxycycline was previously avoided in pregnancy and breastfeeding due to concerns about tooth discoloration and effects on fetal bone development, current evidence has not confirmed these risks. The Society of Obstetricians and Gynaecologists of Canada (SOGC) supports its use for post-exposure prophylaxis in these populations when appropriate, following a careful discussion of risks and benefits[1]. However, for active Lyme disease during pregnancy, doxycycline is not recommended due to the availability of safer alternatives such as amoxicillin or cefuroxime axetil and in cases of severe disease, ceftriaxone. Patients should be advised that prophylaxis may not always prevent illness, especially when delayed, and all individuals, whether or not they receive prophylaxis, should monitor for symptoms for up to one month. This being said, early treatment remains highly effective, and therapeutic failures are rare. Complete guidance on specific cases and pharmacologic options for Lyme disease prophylaxis and treatment can be found here.Prevention essentials for patients Since we do not yet have a vaccine for Lyme Disease, preventing tick bites remains the most effective strategy for protection.Clothing and behavioural strategiesWear light-coloured, long-sleeved shirts and pants to make ticks easier to spot.Tuck pants into socks and stay on well-travelled trails to avoid brushing against vegetation.Shower or bathe within 2 hours of being outdoors to help dislodge unattached ticks.Perform full body tick checks daily, especially checking the following areas:Scalp and hairlineArmpitsGroinBehind kneesWaistband areaUse of tick repellentsDEET and Icaridin are the two main insect repellents licensed in Canada for tick prevention and are safe for use in children over 6 months and adults. For children younger than 6 months, repellents are not recommended, even when the claim is that they contain “natural” ingredients. Instead, it is preferred that children younger than 6 months be clothed with long clothing and the use of a mosquito net over a stroller can also be helpful. Both Icaridin and DEET are generally considered safe in pregnancy and breastfeeding with caution of a maximum of 2 applications daily. Patients should be counselled to apply sunscreen before applying bug repellent and be reminded to only apply repellent on exposed areas while not applying repellents close to the eyes, mouth, or hands. They should also avoid applying repellents to damaged skin or mucous membranes. Learn more about tick repellents here.Tick removal guidelinesPrompt and proper tick removal is a critical step in reducing the risk of Lyme disease and other tick-borne infections. More information on tick removal can be found here.The pharmacist’s role in identification andprevention of Lyme diseasePharmacists play a critical role in supporting early identification and prevention of Lyme disease. They should be aware of local endemic areas and educate patients accordingly, especially during peak transmission months that range from late spring through summer and into the fall.If Lyme disease is suspected, encouraging prompt medical evaluation and treatment at the first sign of symptoms, along with reinforcing vigilance following tick exposure can help ensure timely diagnosis and reduce the risk of disease progression.When advising on testing for patients where travel may be a factor, pharmacists can remind clinicians and patients that the presumed exposure location must be clearly specified, as European Lyme disease (caused by Borrelia afzelii or B. garinii) requires different serologic assays than North American Lyme disease[2]. Pharmacists should emphasize that a typical erythema migrans (EM) lesion, combined with a relevant exposure history, is sufficient for a clinical diagnosis of early Lyme disease—even if initial serologic testing is negative, as test sensitivity is low in the early stages of infection.Vacation season is tick season: Start the conversation!Lyme disease is preventable, treatable, and often overlooked, especially in early stages. Pharmacists play a vital role in helping patients understand their risk, choose appropriate repellents, and recognize when to seek care. By encouraging patients to stay tick-aware during outdoor activities, especially in endemic regions and during peak seasons and by also incorporating tick prevention into seasonal and travel health conversations, pharmacists can empower patients to act early, stay informed, and avoid complications through timely intervention and appropriate follow-up. With the right knowledge and timely guidance, pharmacists can help patients stay one step ahead of Lyme disease at home, on the trail, or wherever their adventures take them.Have a topic in mind? We want to hear from you!If there’s a topic you’d like to see covered in a future installment of this series, let us know! Your input helps ensure we’re addressing the real-world questions and clinical challenges you face in practice.Lindsay Dixon is a Pharmacist, Science Communicator and Health Content Creator. She is the Public Health Ambassador for Heart Pharmacy Group and the Founder of the Friendly Pharmacy 5 Podcast. For collaborations or consulting services: friendlypharmacy5@gmail.com[1] https://pubmed.ncbi.nlm.nih.gov/32414479/[2] https://pubmed.ncbi.nlm.nih.gov/24785207/

Tick season is here—are you ready to counsel with confidence?

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