Revisiting the Prophylactic Treatment for a Known Tick Bite

I’ve touched on the topic of the prophylactic treatment for a known tick bite before but I wanted to expand upon it just a bit as I personally feel that it could cause more harm than good.

Because I have been hearing a number of stories on the misinformation that pharmacists and doctors are giving regarding this treatment protocol, I thought I would provide some basic information here.

First of all, the following is from the NS College of Pharmacists Press Release:

“Screening will include whether the tick was a blacklegged tick, whether the tick bite occurred in the previous 72 hours and whether the tick is attached for at least 36 hours.”

I think screening should also include the question as to how the tick was removed as an improper removal method could force anything the tick was carrying into its host.

I have heard that some pharmacists, and doctors, have advised that they cannot provide the prophylactic treatment because they do not have a bull’s-eye rash. IF you have the better known, but less seen, bull’s-eye version of the erythema migrans (EM) rash then you need to go to a doctor for the full treatment. It’s too late for the prophylactic treatment.

The following is from the NS Health and Wellness News Release:

“The treatment is only recommended if it can be administered within a 72 hour window after the tick is removed. If there are any symptoms of Lyme disease, such as a rash at the bite site, people need to see a doctor or nurse practitioner for other treatment options.”

It is interesting to note that the Centre for Effective Practice (CEP) document “Early Lyme Disease Management in Primary Care” notes that:

“As post-exposure prophylaxis is not 100% effective, patients should be monitored for the development of signs and symptoms for 30 days.”

I have not seen this caveat on any of the Nova Scotia documentation on the issue of prophylactic treatment of a known tick bite. I also noted that the CEP document suggests attachment time of approximately 24 hours, rather than 36.

It is safe to say that the prophylactic treatment of a known tick bite has limited research as to its efficacy. Two meta analyses that I have read have suggested that the available evidence supports the use of a prophylactic dose for the treatment of a known tick bite, but that further confirmation/research is required.

According to the limited research this treatment MAY prevent an EM rash which is one of the easiest ways to diagnose Lyme. It is also of importance to note that antibiotic usage can affect testing for Lyme and can result in a false negative. Without one, or both, of these objective signs it can be problematic to get a proper diagnosis if the post-exposure prophylaxis is not effective.

The correct information needs to be better disseminated to all health care professionals AND the general public.

Education is key.