When a patient walks into my office after a tick bite, they often ask: “Isn’t one dose of doxycycline enough to prevent Lyme disease?”

That belief traces back to a 2001 study that has, unfortunately, shaped Lyme disease treatment guidelines. But what most people don’t realize is that the study only found that the single dose prevented the classic Bull’s-eye rash, not the full spectrum of Lyme disease symptoms. Over time, I’ve seen how treating with only a single dose can leave patients vulnerable to chronic illness.

So today, let’s unpack the science and the clinical reality of this common misperception—in the form of a conversation.

💬 Clinical Dialogue on the Single-Dose Doxycycline for a Tick Bite

Cameron: Let’s talk about the single-dose doxycycline recommendation.

Colleague: The 200 mg dose for tick bite prophylaxis?

Cameron: That’s the one. It’s been included in the IDSA (Infectious Disease Society of America) guidelines since the early 2000’s.

Colleague: Right. The findings were based on the Nadelman study with results indicating an 87% efficacy in preventing erythema migrans rashes if given within 72 hours.

Cameron: But that’s just it. The endpoint was a rash. Not late neurologic Lyme. Not Lyme arthritis.

Colleague: True. And they excluded children, pregnant women, and people who weren’t sure about the timing of the tick bite.

Cameron: Not to mention, no long-term follow-up to monitor for late-onset symptoms.

Colleague: So it’s a narrow window of benefit—for a narrow group of patients.

Cameron: And yet it’s been applied broadly. I’ve seen patients who were told they were “protected,” only to return months later with joint pain, brain fog, or cardiac issues.

Colleague: But isn’t one dose better than nothing?

Cameron: Not if it gives a false sense of security. Or delays treatment.

Colleague: How often do you see that happen?

Cameron: Too often. In my practice, I treat every engorged tick bite. If someone gets sick in the following weeks—even without a rash—I treat empirically.

Colleague: That’s more aggressive than the guidelines.

Cameron: It’s more realistic. We’re not treating mice in a lab. We’re treating people who want to stay well.

Colleague: Have you seen anyone harmed by the one-dose approach?

Cameron: Yes. I had one patient who developed Bell’s palsy and arthritis weeks after the tick bite. She’d been told one dose was enough.

Colleague: But what about antibiotic overuse?

Cameron: That concern matters. But the cost of under-treatment—of letting someone slip into chronic illness—is far greater.

Colleague: So, what’s the alternative?

Cameron: A full 3-week course for anyone with a high-risk bite. And follow-up. Every case deserves more than a one-size-fits-all solution.

🔬 What the Original Nadelman Study Found

The 2001 study by Nadelman et al. showed that a single 200 mg dose of doxycycline could reduce the risk of developing erythema migrans (the bull’s-eye rash) when given within 72 hours of removing an Ixodes scapularis tick.

But it had major limitations:

• No long-term follow-up to determine if patients developed neurologic or arthritic Lyme disease

• Exclusion of high-risk groups (children, pregnant women, unclear exposure)

• No testing for co-infections like Babesia or Anaplasma

• Narrow endpoint focused on a rash—not systemic disease

🩺 Why Clinical Judgment Still Matters

The reality is:

• Not every Lyme case presents with a rash

• Symptoms can develop weeks or months later

• Some patients are misdiagnosed or told they’re fine based on that one dose

• Tick-borne co-infections are rising—and not addressed by doxycycline alone

✅ What I Do Instead in My Practice

In my office, I use a different approach—one rooted in experience, not shortcuts:

• No one-day treatment for tick bites

• Treat every engorged tick bite with a full 3-week course of antibiotics

• Treat any illness that appears within 4–6 weeks of a known tick exposure

• Treat non-classic rashes (not just Bull’s-eye)

• Treat Bell’s palsy with antibiotics, even if tests are negative

• Follow up closely to monitor for evolving symptoms and prevent chronic illness

🧭 Final Thoughts

A one-size-fits-all solution might be convenient—but Lyme disease is complex. 
If we want to prevent long-term suffering, we need to treat the person, not just the tick.