US Pharm. 2012;37(8):12-15.
Tick-borne diseases are the most common vector-borne diseases in North America.1
Public awareness of Rocky Mountain spotted fever (RMSF) and Lyme
disease is fairly high, but there are numerous additional tick-borne
diseases that remain obscure to the public. Occasionally, pharmacists
may suspect that a patient has contracted a tick-borne disease, and
subsequently refer the patient to a physician. The patient may deny
having been bitten. In these cases, it is vital to inform patients that
it is common to not notice a feeding tick because the bite is often
The situation is made more difficult by the nonspecific
nature of many of the signs and symptoms of tick-borne diseases. Fever,
chills, fatigue, malaise, myalgia, and headache each have long and
complicated differential diagnoses. Tick bites are a remote possibility,
so that a good number of patients are undiagnosed and untreated for a
considerable period while the infection continues to cause damage that
may be permanent.
Rocky Mountain Spotted Fever
RMSF is caused by Rickettsia rickettsii, transmitted by Rocky Mountain wood ticks, American dog ticks, and brown dog ticks.1,2
RMSF has been reported in nearly every state. The classic symptoms
consist of fever (of abrupt onset) and a rash that begins on the palms,
soles, wrists, and forearms, spreading to the trunk, neck, and face.
Patients also suffer headache, abdominal pain, anorexia, malaise,
myalgias, red eyes, nausea, and vomiting.2 If the patient’s
infection was severe, long-term health problems are likely. They include
vasculitis, clotting in the brain or other organs, impaired circulation
to the extremities requiring amputation, severe neurologic deficits,
and damage to the internal organs. The disease may be fatal in just 8
days if untreated.2 Prompt doxycycline administration often
yields excellent results. Pharmacists who suspect RMSF should refer the
patient immediately so that care can be instituted.
The pharmacist should be alert to the possibility of Lyme disease in a patient with a recent history of tick bite.1 Lyme disease is caused by a spirochete (Borrelia burgdorferi ) that is transmitted by the bite of the blacklegged tick.1,3
While the first U.S. cases were clustered around Lyme, Connecticut, the
condition has been diagnosed in patients in 49 states. Symptoms of Lyme
disease include a characteristic rash, known as erythema migrans
(a nonpruritic, erythematous, painless maculopapular ring with a
defined border and perhaps a clear center, described as a “bulls-eye”)
and a nonspecific flulike illness causing malaise, fatigue, lethargy,
headache, fever, chills, stiff neck, sore throat, arthralgias, myalgias,
anorexia, nausea, and a malar rash.1,3 The bite site may necrose, resembling a brown recluse spider bite.
Patients must be referred to a physician for immediate
care; delay can increase the risk of debilitating conditions as the
infection spreads to the heart, joints, and nervous system. However,
appropriate and prompt antibiotic therapy (e.g., doxycycline,
amoxicillin, cefuroxime) can prevent sequelae.3
Other Tick-Borne Diseases
A less well-known U.S. tick-borne disease is anaplasmosis.4 Several species of adult ticks bite humans and transfer the bacterium Anaplasma phagocytophilum.
Symptoms, which begin about 7 to 14 days postbite, usually include one
or more of the following: fever, chills, headache, myalgia, malaise,
nausea, abdominal pain, confusion, and rash (rarely).4 The
CDC stresses that doxycycline is the drug of choice for all patients and
must be initiated immediately, confirming the importance of pharmacist
Babesiosis is a tick-transmitted parasitic
condition that may be life-threatening for a patient whose spleen is
absent or hypoactive, whose immune system is weak, who is elderly, or
who has serious underlying health conditions.5 In these
cases, infection can cause hypotension, hemolysis, thrombocytopenia, and
other deadly sequelae. CDC-suggested treatment regimens include
atovaquone, azithromycin, clindamycin, and quinine.5
Several Rickettsial bacteria transmitted by ticks cause a condition known as ehrlichiosis, producing fever, chills, nausea, headache, fatigue, and myalgia.6,7
Less commonly, the patient experiences diarrhea, petechial rash,
maculopapular rash, and malaise. Doxycycline is also the medication of
choice for ehrlichiosis.
Southern tick-associated rash illness (STARI) is
the name given to a lone star tick-borne condition whose cause has not
yet been identified, but which produces fatigue, fever, headache, and
muscle or joint pains.8 A red bull’s-eye lesion develops
around the tick bite, expanding to 3 inches or more (similar to the Lyme
disease lesion). Medications used for Lyme disease may provide relief.8
Tick-borne relapsing fever (TBRF) is a bacterial infection attacking those who sleep in cabins in the mountains where rodents are plentiful.9 Treatments include penicillins, other beta-lactam antibiotics, tetracyclines, macrolides, and fluoroquinolones.9
Tularemia is a tick-borne bacterial infection with
symptoms that vary, but treatment options include streptomycin,
gentamicin, tetracycline, and ciprofloxacin.10
This month’s Patient Information provides tips on
dressing to prevent tick bites in tick-infested areas. Pharmacists can
also advise patients on the use of insect repellents as further
deterrents to bites. Insect repellents must be registered with the
Environmental Protection Agency (EPA) prior to marketing, assuring they
are safe and effective; the EPA has published many consumer-oriented
informational sheets on the topic.11-16 The only two products
proven safe and effective for humans when used properly are DEET and
picaridin. There is no minimum age of use mandated by the EPA.
Therefore, unless the product label has a specific age restriction, the
products are safe for patients of all ages. Human-use insect repellents
do not repel head lice. Further, they should not be used on pets.
DEET 4%-100%: DEET repels mosquitoes, ticks, and chiggers, as well as several biting flies and gnats, when applied to skin or clothing.1,12
While DEET is safe for the majority of users, pharmacists should advise
patients to follow the numerous guidelines to minimize toxicity.1,12
Toxic reactions include altered mental state, paresthesias,
hallucinations, agitation, incoherence, and aggressive and belligerent
behavior.13 There is no age restriction on DEET, and no percentage restriction for children.
To prevent toxicity, DEET must be used sparingly, with just enough to cover exposed skin and clothing.1,12,14
Patients should not exceed the suggested times of application. If the
labeled application regimen is every 8 hours, the product should not be
applied more frequently. DEET should not be used beneath clothing (e.g.,
under a diaper in babies or under the shirt in adults), as application
to an occluded area can increase absorption. It should never be
overapplied, especially using frequent total-body applications. It
should not be applied to abrasions, cuts, wounds, or irritated skin.
Following application, the patient should avoid swimming, toweling the
skin, or situations that would cause sweating. All of these remove DEET
and tempt the patient to reapply sooner than suggested. Children should
not be allowed to use the product themselves, and it should not be
applied near a child’s eyes and mouth. DEET should not be placed on
parts of the child’s body that enter the mouth, such as fingers and
Patients should wash the skin thoroughly with soap and
water after they return indoors, and they should not wear treated
clothing until it has been laundered. If the DEET product is a pump or
aerosol spray, patients must take care not to inhale misted product and
never to spray it in enclosed areas or toward the face. Rather, they
should spray it on the hands and rub it on the face, avoiding the area
around the eyes. DEET is widely available in pharmacies, with some
examples being the OFF! and Repel product families.
Picaridin 5%-20%: Picaridin
is the only other EPA-registered safe and effective insect repellent,
used against biting flies, mosquitoes, chiggers, and ticks.15,16 It is available in some products from Sawyer, Cutter, and Repel.
Area and Clothing Repellents: The
EPA lists three chemicals in the group that can stop insects in an area
or on clothing. Permethrin is an insecticide-repellent approved for use
against ticks, mosquitoes, and other insects when sprayed on clothing,
shoes, socks, and pants.16 It is available in Sawyer Clothing
spray. Allethrin is used to control mosquitoes when heated, in coils,
mats, oils, lanterns, and candles. Metofluthrin controls mosquitoes in
the form of strips, as found in Off! Clip-On, a device that can be
clipped to a belt, purse, or chair. A battery-powered fan circulates the
repellent in the area.17
Biopesticides: Some insect repellents are known as biopesticide repellents,
because they are derived from natural sources such as animals, plants,
bacteria, or minerals (e.g., canola oil, baking soda). Biopesticides are
sold with the claim that they are less toxic than conventional
repellents. Unfortunately, their effectiveness has not been proven, as
they were never investigated for efficacy.11,16 The unproven biopesticide group includes oil of lemon eucalyptus (p-Menthane-3,8-diol), methyl nonyl ketone, IR3535, and citronella oil.16 The most common biopesticide is citronella oil, which claims to repel ticks, mosquitoes, black flies, and fleas.18
It is safe for human use when applied to the skin, and it is also safe
when incorporated into candles and used in recreation areas or outside
of the household.
Unregistered Repellents: In the 1990s, some repellents were determined to pose little risk to humans and did not require EPA approval.11
The EPA is now considering whether these products should be required to
prove safety and efficacy or be removed from the market. Unregistered
repellents include cedar oil, eugenol, garlic, sodium chloride,
cinnamon, thyme, geranium oil, soybean oil, peppermint, and peppermint
oil.19 Until they are proven safe and effective, unregistered repellents should not be recommended.
Preventing Tick Bites
The best advice for preventing tick bites is to simply
stay away from their territories, such as forests, woods, and fields.
However, this would end such recreational activities as picnicking,
hiking, and camping. Thus, the next best advice is to dress in a way
that prevents ticks from contacting your skin. The worst clothing
choices are shorts, sandals, and other apparel that bares the skin. It
is better to wear socks and shoes that cover the entire foot and jeans
or slacks with long legs. Wear shirts with long sleeves that are solid
from shoulder to wrist, and button the sleeves as tightly as possible.
Cover the hands with gloves. Now the skin is shielded, but ticks can
still gain access by crawling up a pants leg or a sleeve.
To stop ticks, it is important to seal access points. Tuck
the pants legs into socks and use duct tape to seal the junction, if
possible. Use more duct tape to seal the glove-sleeve juncture. Finally,
use duct tape to seal the place where the shirt is tucked tightly into
the pants waist. Button the shirt to the top button. Wear a hat.
Occasionally, if the pants and shoes are light in color, examine them to
see if ticks are crawling up to gain access. Brush ticks off and have a
partner check your back for any crawling invaders.
Using Tick Repellents
There are a variety of insect repellents available for
personal use. The most common product is DEET, found in sprays, pumps,
wipes, and lotions (e.g., OFF!, Cutter, Repel). Picaridin is also a safe
choice (e.g., Skin-So-Soft).
Inspecting for Ticks
After you return home, it is important to conduct a full
body inspection to detect ticks. People have found ticks in the most
unlikely locations, such as inside the ears, in the hair, inside the
vagina, and in the eyelids. You must examine every possible part of your
skin. Use a mirror to see spots you cannot visualize directly. Have
someone else check your hair, back, etc.
It is critical to carry out the tick inspection and remove
the arthropods immediately, because studies show that the risk of
getting a disease from an infected tick is far higher if the tick is
able to stay on you and suck your blood for more than 24 hours. Ticks
remain on you for an average of 29 hours, but may stay for more than 48
hours. Your goal should be to remove them as quickly as possible, but
certainly before 24 hours have passed. To remove the tick, grasp it near
its head with tweezers, and pull steadily upwards. When the tick
releases its hold, it can be removed and placed in a jar, labeled with
the date of removal and the area where it was likely caught. If you
develop symptoms later, having the tick can speed a diagnosis.
Remember, if you have questions, Consult Your Pharmacist.
1. Pray WS. Nonprescription Product Therapeutics. 2nd ed. Baltimore, MD: Lippincott Williams & Wilkins; 2006.
2. Rocky mountain spotted fever (RMSF). CDC. www.cdc.gov/rmsf/. Accessed June 25, 2012.
3. Lyme disease. CDC. www.cdc.gov/lyme/. Accessed June 25, 2012.
4. Anaplasmosis. CDC. www.cdc.gov/anaplasmosis/. Accessed June 25, 2012.
5. Parasites—Babesiosis. CDC. www.cdc.gov/parasites/babesiosis/. Accessed June 25, 2012.
6. Ehrlichiosis. CDC. www.cdc.gov/ehrlichiosis/. Accessed June 25, 2012.
7. Ehrlichiosis. PubMed Health. www.ncbi.nlm.nih.gov/pubmedhealth/PMH0002357/. Accessed June 25, 2012.
8. Southern tick-associated rash illness. CDC. www.cdc.gov/stari. Accessed June 25, 2012.
9. Tick-borne relapsing fever. CDC. www.cdc.gov/relapsing-fever/. Accessed June 25, 2012.
10. Tularemia. CDC. www.cdc.gov/tularemia/. Accessed June 25, 2012.
11. Insect repellents: EPA registered vs. unregistered
pesticides. Environmental Protection Agency (EPA).
June 25, 2012.
12. The insect repellent DEET. EPA. www.epa.gov/pesticides/factsheets/chemicals/deet.htm. Accessed June 25, 2012.
13. DEET: Health effects in humans. Agency for Toxic
Substances and Disease Registry.
www.atsdr.cdc.gov/consultations/deet/health-effects.html. Accessed June
14. Using insect repellents safely. EPA. http://epa.gov/pesticides/insect/safe.htm. Accessed June 25, 2012.
15. New pesticide fact sheet: picaridin. EPA. www.epa.gov/opprd001/factsheets/picaridin.pdf. Accessed June 25, 2012.
16. Active ingredients found in insect repellents. EPA.
www.epa.gov/pesticides/health/mosquitoes/ai_insectrp.htm. Accessed June
17. Off! Clip-On. S.C. Johnson & Son, Inc.
Accessed June 25, 2012.
18. Citronella (oil of citronella) (021901) fact sheet.
Accessed June 25, 2012.
19. Minimum risk pesticides. EPA. www.epa.gov/oppbppd1/biopesticides/regtools/25b_list.htm. Accessed June 25, 2012.
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