To the Editor:
While the World Health Organization recommends that, in areas where ticks are only a nuisance, they can be coated with oil, paraffin, petroleum jelly, or nail varnish to prevent them from obtaining oxygen, and thereby facilitate removal, these methods are not recommended in areas where ticks are vectors of disease, as they work too slowly, and may cause ticks to regurgitate into wounds, injecting disease organisms. In such circumstances it is recommended that ticks be pulled out immediately. 1
The Centers for Disease Control recommends tick removal using a pair of fine-tipped tweezers to firmly grasp the tick very close to the skin and, with a steady motion, pull the tick's body away. 2 Unfortunately, this method carries a risk of crushing the tick's body (thorax, head), particularly for tiny species. This may force infectious body fluids through the tick's mouth parts into the wound site.
We conducted a study aimed to investigate if ticks attached to human skin could be effectively removed by tightening a single overhand knot in a monofilament fishing line around the tick's mouth parts to force the tick from the skin. 3 We used fishing line because of its round and smooth surface and because it is readily available. We received approval for the study from the Italian Committee of Physicians for Environment and Health, a nonprofit organization.
As our study area is not infested with ticks, it took several years so to enroll patients with spontaneously attached ticks. In our area, attached ticks are usually immediately removed by patients or parents of children.
Walk-in patients between the ages of 4 and 13 years with embedded ticks were enrolled. Parents were shown a video clip to illustrate the technique, and were informed that this was not the currently recommended technique for tick removal but rather an experimental technique. Verbal permission was obtained for a maximum of 3 attempts at tick removal with the technique. Tweezers were to be used to remove ticks that remained after 3 attempts in order to avoid further delay in removal and possibly an increase in the chance of disease transmission. After removal, the ticks were placed in 70% ethanol for microscopic evaluation of the mouth parts.
Technique
Twenty centimeters of fishing line (diameter 0.4 mm, thinner for small, immature specimens) is used to slowly tie a simple, overhand knot between the skin and the tick's head. The line is pressed against the skin while being gently pulled, so that the knot tightens around the tick's mouth parts. The ends of the line are pulled slowly and steadily as the tick is eased out of the skin (Figure). Avoid tightening the knot sharply, as this may tear the mouth parts from the body of the tick, leaving them embedded in the skin.
Fishing line knot being used to remove a tick from a child's leg. A video of this removal is available at:
Ten patients with 17 attached Ixodes ricinus nymph ticks identified by a veterinarian expert in entomology were enrolled. Attempts at tick removal were made by a pediatrician or a dermatologist (both of whom had some prior experience with the technique). In the majority of the cases it was unknown how long the tick had been attached.
One tick (5.8 %) was removed on the first attempt, 7 (41.1%) on the second, and 9 (52.9%) on the third, for a 100% success rate.
The ticks were all less than 2.5 mm in length. Twelve ticks were completely removed with the fishing line knot. The remaining 5 ticks had some retained mouth parts that were removed with very fine-tipped tweezers. Success rate for removing the ticks intact was 71%. All ticks were still alive on removal. In an effort to assess for any complications, we called the families of all patients at 1, 2, and 4 weeks after tick removal. Parents were asked about fever, rash, headache, myalgia, respiratory tract symptoms, and any sign where the tick had been attached. These calls revealed no patients with concerns for local infection or zoonoses.
In conclusion, tick removal by tightening a fishing line knot between the patient's skin and the tick's head is a simple technique that appears to have a high success rate. It may be particularly helpful for removal of tiny species. Body areas covered with hair may make this method more difficult to apply.