TICKS AND TRANSMISSION: NASTY LITTLE BUGS
NASTIER DISEASE
Faculty:
Jeanette Y. Wick, RPh, MBA, FASCP
Jeannette Y. Wick is the Director of the Office of Pharmacy Professional Development at the University of Connecticut.
Pamela Sardo, PharmD, BS
Pamela Sardo, PharmD, BS, is a freelance medical writer and licensed pharmacist. She is the founder and principal at Sardo Solutions in Texas. Pam received her BS from the University of Connecticut and her PharmD from the University of Rhode Island. Pam’s career spans many years in retail, clinics, hospitals, long-term care, Veterans Affairs, and managed health care responsibilities across a broad range of therapeutic classes and disease states.
Abstract
The various types of ticks across the United States can cause several diseases. The incidence of tick-borne diseases more than doubled between 2004 and 2016. Many of these diseases have similar non-specific symptoms, and misdiagnosis or delayed diagnosis is common. While prevention is the best approach to these diseases, they still occur with alarming frequency. Pharmacists and pharmacy technicians who know how to identify and differentiate tick-borne diseases can help patients and the healthcare team make diagnoses and treat them appropriately. For most (but not all) tick-borne diseases, doxycycline is the drug of choice for treatment.
Accreditation Statements
In support of improving patient care, RxCe.com LLC is jointly accredited by the Accreditation CouncilTM for Continuing Medical Education (ACCME®), the Accreditation Council for Pharmacy Education (ACPE®), and the American Nurses Credentialing Center (ANCC®), to provide continuing education for the healthcare team.
Joint Universal Activity Number: The Joint Accreditation Universal Activity Numbers assigned to this activity are as follows:
Pharmacists: JA4008424-0000-26-125-H01-P
Pharmacy Technicians: JA4008424-0000-26-125-H01-T
Credits: 2 contact hour(s) (0.2 CEU(s)) of continuing education credit.
Credit Types:
Pharmacy - 2 Credits
Type of Activity: Knowledge
Media: Computer-Based Training (i.e., online courses)
Estimated time to complete activity: 2 contact hour(s) (0.2 CEU(s)), including Activity Pre-Test, Post-Test, and Activity Evaluation.
Release Date: June 29, 2026 Expiration Date: March 12, 2027
Target Audience: This educational activity is for Pharmacists and Pharmacy Technicians
How to Earn Credit: From June 29, 2026, through March 12, 2027, participants must:
Read the “learning objectives” and “author and planning team disclosures;”
Take the “Educational Activity Pre-Test;”
Study the section entitled “Educational Activity;” and
Complete the Educational Activity Post-Test and Activity Evaluation. The Educational Activity Post-Test will be graded automatically. Following successful completion of the Educational Activity Post-Test with a score of 70% or higher, a statement of participation will be made available immediately. (No partial credit will be given.)
CE and CME Credits: Credits for this course will be uploaded to CPE Monitor® for pharmacists and pharmacy technicians.
Statement of Need
Various types of ticks transmit infectious pathogens known as vector-borne diseases. Alpha-gal syndrome has also emerged as a health threat. It is not an infection but a serious allergy that develops in some people after a tick bite. Clinicians need to know the less common tick-borne diseases, their symptoms, appropriate treatments, and understand the symptoms indicating a patient may have alpha-gal syndrome.
Pharmacists Learning Objectives: Upon completion of this educational activity, participants should be able to:
Describe the types and symptoms of tick-borne infections
Identify each infection’s treatment based on CDC guidelines
Recall counseling points for patients and advice for prescribers
Pharmacy Technicians Learning Objectives: Upon completion of this educational activity, participants should be able to:
Review tick-borne infections and their symptoms
List medications used for tick-borne infections
Repeat information that is within the technician’s scope of practice
Disclosures
The following individuals were involved in planning, developing, and/or authoring this activity: Jeannette Y. Wick, RPh, MBA, FASCP; and Pamela Sardo, PharmD, BS. None of the individuals involved in developing this activity has a conflict of interest or financial relationships related to the subject matter. There are no financial relationships or commercial or financial support relevant to this activity to report or disclose by RxCe.com or any of the individuals involved in the development of this activity.
© RxCe.com LLC 2026: All rights reserved. No reproduction of all or part of any content herein is allowed without the prior, written permission of RxCe.com LLC.
Educational Activity Pre-Test
Which of the following tick-borne diseases would be considered a serious rickettsial disease?
Anaplasmosis
Babesiosis
Ehrlichiosis
Rocky Mountain spotted fever
A patient reported removing an engorged tick from her back six weeks ago. She has struggled with nausea and anorexia for the last week. Her favorite meal was a Big Mac with French fries, but even the thought of it now makes her want to throw up. Her tests for Lyme disease were negative. She has type O blood and a history of allergies. What might her diagnosis be?
Anxiety
Hypochondria
Pregnancy
Alpha-gal (α-gal) syndrome
What do the guidelines recommend when treating patients who are highly immunocompromised?
Starting with a low dose and increasing the antibiotic gradually
Starting with regimens using the highest recommended doses
Using a medication other than doxycycline for tick-borne diseases
Discontinue any corticosteroids or meds for the immune condition
Educational Activity
Ticks and Transmission: Nasty Little Bugs, Nastier Disease
Introduction
Various types of ticks transmit infectious pathogens known as vector-borne diseases. Lyme disease is the most common vector-borne disease, but other tick-borne diseases, such as Rocky Mountain Spotted Fever, anaplasmosis, babesiosis, ehrlichiosis, and tularemia, also pose serious threats to human health. Alpha-gal syndrome has also emerged as a health threat. It is not an infection but a serious allergy that develops in some people after a tick bite. This continuing education activity discusses other, less common tick-borne diseases, their symptoms, appropriate treatments, and alpha-gal syndrome.
An Overview of Ticks and Tick-borne Illnesses
Ticks are interesting little arachnids (joint-legged arthropods), and they cause much human suffering. First identified as vectors of disease transmission in 1906,1 they are associated with at least 12 different human diseases in the United States, as listed in Table 1 below.3
The incidence of tick-borne diseases more than doubled between 2004 and 2016.2 While Lyme disease accounted for approximately 82% of tick-borne cases in the United States, cases of spotted fever rickettsioses, babesiosis, anaplasmosis, and ehrlichiosis also increased.2
POINT TO PONDER: Why is it important to know about tick-borne diseases in your areas of the United States? |
Table 1
Tick-borne Diseases that Occur in the United States3
| Type of Infectious Agent | Possible Disease |
| Bacteria | |
| Borrelia | Lyme borreliosis |
| Riskettsia (non-spotted fever group) | Anaplasmosis, ehrlichiosis |
| Riskettsia (non-spotted fever group) | Rocky Mountain spotted fever. Rickettsiosis, Rickettsia parkeri rickettsiosis |
| Francisella tularensis | Tularemia |
| Protozoan | |
Babesia microti, B. divergens | Babesiosis |
| Arboviral | |
| Coltivirus (Spinareoviridae) | Colorado tick fever |
| Bandavirus RNA virus | Heartland virus disease |
| Bourbon virus | Bourbon virus disease |
| Powassan virus | Powassan virus disease |
Many diagnosticians have a low index of suspicion for tick-borne diseases because of the vague nature of their symptoms and the possibility of coinfection. Overall, 39% of patients will be co-infected with more than one tick-borne organism.4 Clinicians should suspect co-infection with other tick-borne illnesses if patients receive appropriate treatment for Lyme disease but continue to experience fever for more than 24 hours or have unexplained thrombocytopenia and/or anemia.5
The most common co-infection with Lyme disease is babesiosis, and a small number of patients (less than 5%) will have triple infections (usually Lyme plus anaplasmosis and babesiosis).4 These rates of prevalence are in line with recent studies. A 2024 study analyzed a database including more than 3000 babesiosis patients and found that 4 in 10 were coinfected with tick-borne zoonoses, including Borrelia burgdorferi, ehrlichiosis, and anaplasmosis.6 They also reported an overall coinfection rate of 37%, with Borrelia burgdorferi having the highest rate of coinfection at 30%, followed by anaplasmosis at 4.5%. Co-infections with Borrelia burgdorferi and anaplasmosis were reportedly 2.3%. These findings were in agreement with a similar report published in 2017.6,7
Earlier studies found that disease severity tends to be worse in patients with co-infection, and symptoms may last longer.4 While this can be the case, Babesia patients coinfected with other tick-borne pathogens did not have a higher mortality risk or more severe disease.6,7
There are other factors that clinicians should consider. For example, older age and a history of splenectomy are risk factors for more severe illness in coinfection.4
Why Do We Need Ticks
This section asks, “Why do we need ticks?” In other words, if we could eradicate ticks, what would change except the elimination of tick-borne disease? Ticks, like most other organisms, have assigned places in the ecosystem.8,9 Amphibians, birds, reptiles, wild turkeys, and various other animals consume ticks. Opossums are inordinate consumers of ticks and devour them relentlessly, as do guinea fowl.9 Scientists also track tick activity to monitor ecosystem status and changes. Abundant tick populations are usually associated with healthy populations of small mammals like rodents, squirrels, and rabbits. If tick populations decline, it can indicate that predators of small animals may be overabundant. Tick populations also track climate change. Warming temperatures make conditions more hospitable for ticks and their animal hosts, creating opportunities for ticks to spread disease. As temperatures rise, ticks multiply.8,9 Recently, scientists have used ticks to analyze levels of environmentally persistent, ubiquitous pollutants called PFAS (per- and polyfluoroalkyl substances from plastics) because ticks “visit” many species and accumulate PFAS. They are sentinels of PFAS contamination.10
How Pathogens Modify Tick Behavior
Various types of ticks transmit infectious pathogens to other living organisms; in this capacity, ticks are called vectors.11 Ticks are sedentary predators that employ a position known as questing to find prey. They grip leaves, grass, or underbrush using their third and fourth pair of legs, holding their first pair of legs outstretched.12,13 Hosts that brush against the waiting tick become the tick’s prey.
The tick’s lifespan from birth to death is short, usually spanning two to three years and progressing through egg, larval, nymph, and adult stages.14 Their survival during the larval and nymph stages requires a new host for a blood meal for growth to the next stage. Adult females need a blood supply to produce eggs. Nymphal and larval forms of the Ixodes tick rely on the white-footed mouse for nourishment, while adult ticks feed on deer. Black-legged ticks can feed on mammals, birds, reptiles, and amphibians. Ticks acquire Borrelia and other pathogens from infected hosts, and interestingly, female ticks do not transmit Borrelia to their offspring.14
Identifying ticks correctly is critical when discussing tick-borne diseases, as diseases are often species-specific. For example, Ixodes ticks transmit Lyme disease, and Dermacentor transmits rickettsia. For this reason, experts advise people who are bitten to remove ticks properly, save them, and submit them to the local health department for identification.15
As researchers learn more about tick-borne diseases, they have found answers to many questions. They have determined that organisms with complex life cycles, such as ticks, are more likely to be disease vectors. They have noted that infected ticks seem to be hardier than uninfected ticks. It also appears that pathogens modify tick behavior in remarkable ways:16
Infection with Borrelia and tick-borne encephalitis virus increases overall tick mobility considerably and improves phototaxis, enabling ticks to climb to higher questing heights; infected ticks can also walk faster and farther than uninfected ticks.
Borrelia and Anaplasma infections improve desiccation resistance in Ixodes ticks, allowing them to increase their fat reserves and synthesize heat shock proteins.
Anaplasma infections improve cold resistance in infected ticks.
Coinfection with Borrelia, Anaplasma, and B. microti lengthens life in infected ticks.
Babesia infection also helps ticks feed better (and become more engorged).
For these reasons, researchers describe infection as a win-win strategy for the pathogens and the ticks.
Ticks and Disease Transmission
Ticks infected with a pathogen may transmit disease to humans when they bite. These tick-borne diseases include Rocky Mountain Spotted Fever, anaplasmosis, babesiosis, ehrlichiosis, and tularemia. In addition, this section will discuss alpha-gal syndrome.
Rocky Mountain Spotted Fever and Rickettsiosis
Rocky Mountain Spotted Fever (RMSF) is discussed first because it was the first tick-borne disease identified.1 It is the most severe rickettsiosis in the United States. Howard Taylor Ricketts, an American pathologist, identified the Dermacentor andersoni wood tick as the vector for RMSF in 1906, and ultimately researchers found that other tick species, such as the American dog or wood tick (Dermacentor variabilis), were also vectors for RMSF.1
The pathogen family for RMSF, Rickettsiaceae, is named after Dr. Ricketts. Dr. Ricketts’ devotion to research was admirable but rather risky; he injected himself with suspected pathogens on several occasions. He was often so absorbed in his work that he became absent-minded. One anecdote about Ricketts describes his arrival home to find that his daughter had a temperature of 102°F. He responded that it was normal, but later realized he was preoccupied and incorrect. He admitted he had been thinking of guinea pigs, in which a temperature of 102°F would be normal.1
Five states (Arkansas, Missouri, North Carolina, Oklahoma, and Tennessee) report more than 60% of RMSF cases, with cases peaking in the summer months (May through August).17 Of importance, RMSF occurs year-round in Arizona and Northern Mexico, which report unusually high incidences and case fatality rates, especially in children.18
Rocky Mountain Spotted Fever’s symptoms begin between three and 12 days after a tick bite.19 It generally begins with the abrupt onset of fever and headache that often prompt patients to seek care. Patients may develop gastrointestinal symptoms (nausea, vomiting, anorexia), acute abdominal pain that may be confused with appendicitis, myalgia, or a rash that appears two to four days after the fever starts. Most of these symptoms are similar to those seen in other tick-borne diseases. One symptom that is different is edema around the eyes and on the back of the hands. More than 90% of patients develop small, flat, pink macules on the wrists, forearms, and ankles that spread to the trunk. Sometimes, the rash covers the palms and the soles of the feet.19
Rocky Mountain Spotted Fever is rapidly progressive, and immediate treatment is critical.19 Untreated, late illness develops, defined as symptoms after day 5. Untreated patients may develop petechiae (small spots of pinpoint bleeding under the skin) on day 5 or 6, which signals severe disease. Patients with severe disease may have altered mental status, coma, or cerebral edema; respiratory compromise (pulmonary edema, acute respiratory distress syndrome); necrosis from blood vessel damage that may lead to amputation; or multiorgan system damage. Risk factors for severe illness include delayed treatment, age younger than 10 (children account for 6% of cases but 11% of deaths), and glucose-6-phosphate dehydrogenase deficiency. After recovery from severe RMSF, patients often have permanent damage, including hearing loss, paralysis, or cognitive compromise. The acute illness causes permanent damage, and RMSF does not become a chronic infection.19
Without early administration of doxycycline, RMSF can be fatal within days.19 Adults should receive 100 mg of doxycycline every 12 hours, and children weighing less than 45 kg (100 lbs) should receive 2.2 mg/kg body weight, given twice daily for at least 3 days after the fever subsides and clinical improvement is evident. All patients must be treated for at least five days and often longer.19
Pharmacy teams should note that starting in 1970, experts advised against using doxycycline in children younger than 8.20 The advice has changed. Using doxycycline for five to 10 days has been proven not to stain permanent teeth, cause enamel hypoplasia, or alter growth. Doxycycline is the first-line treatment for suspected RMSF in patients of all ages.20 Chloramphenicol is the alternative antibiotic for RMSF, but it is less effective. Patients with RMSF must not be treated with sulfa-containing drugs, as they worsen the clinical course and increase the risk of death.19
Anaplasmosis
A Gram-negative, obligate intracellular bacterium that infects leukocytes causes anaplasmosis, formerly known as human granulocytic ehrlichiosis.21 The Ixodes tick transmits its causative bacterium, A. phagocytophilum; similar to Lyme disease, the regional distribution of anaplasmosis is the Northeastern United States, upper Midwest, and northern California. Its prevalence peaks in the spring and summer.21 Recommended diagnostic tests include polymerase chain reaction (PCR) amplification on DNA extracted from whole blood specimens early in the illness (meaning in the first weeks). Note that a negative PCR does not rule out anaplasmosis. An indirect immunofluorescence antibody (IFA) assay is used to identify A. phagocytophilum, and patients must submit blood samples twice, two to four weeks apart.
Unlike Lyme disease, anaplasmosis is rarely associated with a rash.21 Patients who contract anaplasmosis usually present with fever, malaise, myalgias, and severe headache within 1 to 2 weeks after a tick bite. They may also experience nausea, vomiting, and anorexia. Lab work may reveal various abnormalities, including leukopenia, thrombocytopenia, and elevated transaminases. If patients delay treatment, severe illness can develop, with possible respiratory failure, bleeding abnormalities, organ failure, and potentially death. Older age and being immunocompromised increase the likelihood of severe illness.22
Experts recommend treatment with a 10-day course of doxycycline. In adults, the dose is 100 mg every 12 hours. In children weighing less than 45 kg (100 lbs), the dose is 2.2 mg/kg, given twice daily.22
POINT TO PONDER: Which tick-borne diseases should be treated with doxycycline, and which would ideally be best referred to an infectious disease specialist? |
Babesiosis
Babesiosis, a protozoan infection of the red blood cells, describes two human infections:23,24
Infection with Babesia microti. B. microti is transmitted to humans by Ixodes ticks with a disease distribution similar to Lyme disease.25
Infection with B. divergens in immunocompromised human hosts, mainly in cattle-ranching regions during summer months.26
In nearly one-half of the cases, patients are co-infected with Lyme disease.6,7,27,28 Young, healthy patients with babesiosis are often asymptomatic. If symptoms develop, they are usually non-specific. Patients may experience a self-limited influenza-like low-grade febrile illness with anorexia, malaise, and lethargy. Complications can include hemolytic anemia, jaundice, and acute respiratory failure.27,28
Lab abnormalities include mild hemolytic anemia and thrombocytopenia.27 Treatment guidelines recommend using peripheral blood smear examination or PCR rather than antibody testing because Babesia antibodies can persist for a year or more after the infection has appeared to clear with or without treatment.27,28
Treatment is based on infection severity. Mild to moderate disease in immunocompetent patients is treated with azithromycin, with a loading dose of 500 to 1000 mg followed by 250 to 1000 mg daily, and atovaquone, 750 mg twice daily, for 7 to 10 days. If babesiosis is severe, prescribers should employ quinine 650 mg three times daily and clindamycin 600 mg orally three times daily or 300 to 600 mg intravenously four times daily.27,28 Supportive care may include antipyretics. Patients with low or unstable blood pressure may require a vasopressor. In severe cases, blood or exchange transfusion, mechanical ventilation, or dialysis may be needed. If patients are highly immunocompromised, the guidelines recommend starting with regimens using the highest recommended doses or those recommended for hospitalized patients for six consecutive weeks or longer.27,28
Ehrlichiosis
Three bacteria cause ehrlichiosis in the United States: Ehrlichia chaffeensis, E. ewingii, and E. muris eauclairensis, with E. chaffeensis implicated most often.29 Clinicians are more likely to see cases in the southcentral and eastern U.S., where the lone star tick (Ambylomma americanum) is endemic. Cases linked to E. muris eauclairensis have only been reported in Minnesota and Wisconsin (as the name Eau-Clair-ensis suggests). The number of cases peaks in June and July every year.29
Signs and symptoms typically begin within five to 14 days after the bite of an infected tick.29 Ehrlichiosis presents as an acute febrile illness with chills and rigors, but its presentation varies widely among individuals and may include headache, malaise, myalgia, gastrointestinal symptoms (nausea, vomiting, diarrhea, anorexia), confusion, and rash. The rash is an interesting symptom, as it usually begins within five days of the first symptoms and occurs in up to 60% of children but only half as many adults. It usually appears on the body, but not the face, and may be maculopapular or petechial.29
Here, too, most cases are mild or moderate, but severe illness and death are possible.29 Severe illness is most likely to occur in patients who are very young, very old, or immunocompromised. Severe symptoms may include meningitis, meningoencephalitis, and other central nervous system involvement (which occurs in up to 20% of patients). Other complications may include acute respiratory distress syndrome, toxic shock-like or septic shock-like syndromes, renal or hepatic failure, or coagulopathies.29
No stand-alone guidelines exist for ehrlichiosis. Recommendations from the Centers for Disease Control and Prevention (CDC) are comprehensive and generally cover ehrlichiosis. Adults should receive 100 mg of doxycycline every 12 hours, and children weighing less than 45 kg (100 lbs) should receive 2.2 mg/kg given twice a day for at least three days after the fever subsides and clinical improvement is evident. All patients must be treated for at least five days.29
Tularemia
Tularemia, caused by the bacterium Francisella tularensis, is also known as rabbit fever because rabbits, hares (which are larger and have longer ears than rabbits), and rodents are particularly susceptible and frequently die in large numbers during outbreaks. F. tularensis can also be spread by deer flies, contact with infected animals, drinking contaminated water, or breathing contaminated dust. Its name is derived from Tulare County, California, where the disease was discovered in 1911.30 It is thankfully rare, with fewer than 300 cases reported annually.31
Symptoms of tularemia usually present one to 21 days after exposure, but most human infections develop in three to five days. Symptoms may include fever/chills, skin ulcers, and enlarged lymph nodes. Patients may also develop headache, malaise or fatigue, anorexia, chest discomfort, cough, sore throat, vomiting, diarrhea, and abdominal pain.31 Table 2 describes characteristic clinical variants of tularemia that develop based on the route of inoculation.31
Table 2
Clinical Variants of Tularemia and Their Presentations31
| Variant | Presentation |
| Ulceroglandular | Accounts for 75% of cases Usually occurs following a tick or deer fly bite or after handling an infected animal Localized lymphadenopathy and sometimes a cutaneous ulcer at the infection site |
| Oculoglandular | Follows bacterial entry through the eye (e.g., when a person touches their eye after handling infectious material) Symptoms include photophobia, excessive lacrimation, conjunctivitis, and preauricular, submandibular, and cervical lymphadenopathy |
| Oropharyngeal | Occurs after eating or drinking contaminated food or water. Symptoms include severe throat pain, exudative pharyngitis or tonsillitis, and cervical, preparotid, and/or retropharyngeal lymphadenopathy |
| Pneumonic | Occurs after breathing contaminated dust or aerosols, or secondary to other untreated forms of tularemia Symptoms include cough (dry or productive), substernal tightness, pleuritic chest pain, and hilar adenopathy Infiltrate or pleural effusion may be present on chest imaging |
| Typhoidal | Any combination of the general symptoms, without localizing symptoms of other specific presentations |
Patients will develop a fever ranging from moderate to very high, and once it develops, the lab can isolate tularemia bacilli from blood cultures. Patients will experience facial and ocular redness and inflammation that can spread to the lymph nodes, which enlarge and may exude pus if the patient also has a high fever.31 Diagnosis follows isolation of F. tularensis from swabs or scrapings of ulcers, lymph node aspirates or biopsies, pharyngeal swabs, or respiratory specimens (e.g., pleural fluid). Laboratories need to know if F. tularensis is suspected so they can incubate cultures for extended periods, as it grows slowly. Clinicians can also monitor seroconversion from negative to positive IgM and/or IgG antibodies by testing two serum samples: one within the first week of acute onset and the second two to three weeks later.31
In this tick-borne infection, patients will need immediate treatment beyond doxycycline alone, and in this instance, clinicians should seriously consider consulting an infectious disease specialist.31 Table 3 describes current treatment recommendations. Gentamicin is preferred for the treatment of severe tularemia, and infectious disease specialists may recommend combination therapy. Gentamicin and ciprofloxacin are used off-label in this indication.31
Table 3
Recommended Treatments for Tularemia31
| Age | Antibiotic | Dosing | Notes | Duration |
|---|---|---|---|---|
| Adults | Gentamicin | 5 mg/kg IM or IV daily (with desired peak serum levels of at least 5 mcg/mL) | Monitor serum trough levels Adjust dose in renal insufficiency | 10 – 14 days |
| Ciprofloxacin | 400 mg IV or 500 mg PO twice daily | N/A | 10 – 14 days | |
| Doxycycline | 100 mg IV or PO twice daily | N/A | 14 – 21 days | |
| Children | Gentamicin | 2.5 mg/kg IM or IV 3 times daily or as recommended by an infectious disease specialist | Monitor serum trough levels and consult a pediatric infectious disease specialist Adjust dose in renal insufficiency | 10 – 14 days |
| Ciprofloxacin | 15 mg/kg IV or PO twice daily | 800 mg per day | 10 – 14 days | |
| Doxycycline | 2.2 mg/kg IV or PO twice daily | 100 mg IV or PO twice daily | 14 – 21 days | |
| *Not a U.S. FDA-approved use but has been used successfully to treat patients with tularemia. **Once-daily dosing could be considered in consultation with a pediatric infectious disease specialist and a pharmacist. | ||||
Alpha(α)-gal Syndrome
A CDC report showed that between 2010 and 2022, clinicians reported more than 110,000 suspected cases of α-gal syndrome.32,33 However, α-gal syndrome is not a nationally notifiable disease, so the CDC indicates many cases may be unreported or undiagnosed.32 The CDC has made a public push to heighten awareness of this tick-borne, serious, potentially life-threatening allergic condition.32 α-gal syndrome is also called α-gal allergy, red meat allergy, or tick bite meat allergy. α-gal syndrome is not an infection but a serious allergy that develops in some people after a tick bite. Symptoms occur after consuming red meat or exposure to products containing α-gal.32,33
POINT TO PONDER: Which patients are most likely to develop α-gal Syndrome, and what should pharmacy staff monitor? |
Alpha-gal (galactose-α-1,3-galactose) is a sugar molecule that is present in non-primate mammals but not birds, fish, or humans. It is present in red meats and in products made from mammals, such as gelatin, cow’s milk, and milk products. α-gal syndrome has been linked to bites from lone star ticks in the U.S.32,33 The CDC is unsure if other ticks can cause α-gal syndrome, but several tick species have been proven to cause α-gal syndrome in other countries.32 In addition to the risk factors associated with tick bites, a small study found that certain people are more likely to develop α-gal syndrome. Predisposing factors included the following:34
a history of childhood allergies
allergies to foods other than red meat
A propensity to have cutaneous reactions to insect bites, and
sIgE antibodies to many allergens
family members (parents, siblings, and children) with food allergies and insect-bite allergies.
The researchers indicated that patients with α-gal syndrome were roughly eight times as likely to report related family members with α-gal syndrome.34 A or O blood types seem to increase the risk, while the risk in people with AB or B blood types seems to be lower. These findings suggest a genetic component for susceptibility.34
Alpha-gal allergic reactions range from mild to life-threatening anaphylaxis.35 Affected patients will experience symptoms two to six hours after consuming meat or other mammalian products. Symptoms may include hives; swelling of the lips, tongue, throat, or eyelids; cough; difficulty breathing; wheezing; heartburn; nausea or vomiting; abdominal pain; diarrhea; or decreased blood pressure. Diagnosis requires blood testing to detect antibodies against the α-gal sugar molecule.35
If patients have mild α-gal symptoms, antihistamines can help. Those who experience more severe reactions will require intramuscular epinephrine and may need supportive care in the emergency department.33
Patients with α-gal syndrome must abstain from mammalian meat (e.g., beef, pork, or lamb) and should avoid future tick bites. Some affected patients may need to stop consuming mammalian-based products (such as cow’s milk, cheese, or gelatin). The CDC maintains a list of α-gal-containing products here: https://www.cdc.gov/ticks/alpha-gal/products.html.36 Clinicians should avoid prescribing α-gal-containing medications (e.g., heparin, snake antivenom, certain cancer medications [such as cetuximab]), and mammal-based organ replacements (such as heart valves).
A Word About Pregnancy
Clinicians should approach the diagnosis and laboratory testing of tick-borne diseases in pregnant women in accordance with current recommendations and guidelines for other adult patients. As noted above, prescribers avoided doxycycline in pregnancy and children younger than eight because of concerns about adverse effects (teeth staining and delayed bone growth). A systematic review indicated that these concerns are unwarranted.37 However, if a pregnant woman cannot take doxycycline, clinicians may consider using oral amoxicillin 500 mg three times daily or oral cefuroxime axetil 500 mg twice daily for 14 to 21 days. Azithromycin 500 mg is an alternative, but there is less evidence supporting its use. The safest approach to treating pregnant women in whom doxycycline is contraindicated is consultation with an infectious disease specialist.37
In the Pharmacy
Dealing with tick-borne disease is complicated, and patients often cannot remember or do not notice a tick bite—a situation that occurs in 30% to 50% of individuals.38 Ixodes ticks are about the size of a sesame seed, while common dog ticks are 5 mm or larger (the size of a pencil top eraser). Larval and nymphal ticks (which are often implicated in tick bites) are a few millimeters in diameter; adult ticks are larger. Tick bites are easy to miss. This is yet another reason why misdiagnosis or delayed diagnosis is common.39
Pharmacists and pharmacy technicians will note that in almost all tick-borne diseases, doxycycline is the drug of choice. Healthcare providers should be cautious when exploring treatments other than doxycycline for most tick-borne infections, and consulting an infectious disease specialist is a smart move. A key point to remember is that package inserts still advise against using doxycycline during tooth development (the last half of pregnancy, infancy, and childhood through age 8).40 This information is now outdated, and doxycycline is considered a front-line short-term treatment for tick-borne diseases in children and pregnant women.41 Doxycycline can cause photosensitivity; patients should limit sun exposure and use sunscreen while taking it. The most common adverse reactions include anorexia, nausea, vomiting, diarrhea, rash, photosensitivity, urticaria, and hemolytic anemia.40
Pharmacists need to screen for drug interactions with doxycycline. Prescribers may need to adjust anticoagulant therapy downward.40 Doxycycline should not be given concurrently with penicillin. Concurrent antacids containing aluminum, calcium, magnesium, bismuth subsalicylate, and iron-containing preparations will impair doxycycline’s absorption. Some evidence suggests that the concurrent use of tetracyclines decreases oral contraceptives’ effectiveness, and patients should use a backup measure to prevent pregnancy. Barbiturates, carbamazepine, and phenytoin decrease doxycycline’s half-life. Patients should also take doxycycline on an empty stomach.40
Encouraging and monitoring adherence is critical. Applying appropriate auxiliary labels and counseling the patient to take the medication precisely as prescribed can improve outcomes. Pharmacy teams should recommend using adherence tools, such as cell phone alarms or medication boxes, to ensure complete adherence throughout the entire course of treatment.
One important point to make and repeat: contracting a tick-borne disease does not confer immunity, so patients need to take steps to prevent future bites.42 Prevention needs to be emphasized repeatedly, as does prompt removal of ticks. Table 4 provides links to materials that can help patients prevent tick exposure, use appropriate tools and techniques for tick removal, identify ticks by species, and understand tick-borne diseases.
Knowing which effective insecticides are in stock in the pharmacy is also important. The CDC recommends treating clothing and gear with products containing 0.5% permethrin. The Environmental Protection Agency (EPA) produces and maintains a list of registered insect repellents effective against ticks; the list includes repellents containing DEET, picaridin, IR3535, oil of lemon eucalyptus (OLE, which must not be used on children younger than 3), para-menthane-diol (PMD), or 2-undecanone. The EPA also provides a search tool that helps individuals find appropriate products (see https://www.epa.gov/insect-repellents/find-repellent-right-you). On this site, patients indicate how much time they will spend outside, which organism they want protection against, and the search engine does the rest.
Table 4
Patient Resources for Tick Bite Prevention and Detection
| Organization | Material provided |
Centers for Disease Control and Prevention. Preventing Tick Bites https://www.cdc.gov/ticks/prevention/?CDC_AAref_Val=https://www.cdc.gov/ticks/avoid/on_people.html | Pre-exposure directions to deter ticks A link to Environmental Protection Agency-registered insect repellents Directions for a post-exposure full-body check |
Centers for Disease Control and Prevention. It’s open season on ticks! https://www.cdc.gov/ticks/media/pdfs/Its-Open-Season-on-Ticks.pdf | Protect yourself, your family, and your pets from tick bites this hunting season. Treat gear and clothing with products containing 0.5% permethrin. Tuck your pants into your boots or socks and tuck your shirt into your pants to prevent ticks from crawling inside your clothing. |
Centers for Disease Control and Prevention. Ticks https://www.cdc.gov/ticks/index.html | Comprehensive information about ticks and the diseases they carry Has a tick bite data tracker Also includes materials about anaplasmosis, babesiosis, ehrlichiosis, Lyme disease, and Rocky Mountain spotted fever |
Individuals diagnosed with α-gal syndrome are typically prescribed an epinephrine auto-injector to use if they develop a severe allergic reaction.43 Pharmacy technicians can be of great help in that case and remind patients to note the expiration date so they can replace the medication. They also need to remind parents to review local school policy and ensure the school identifies employees who can administer the injection at school and on field trips. In addition, pharmacy technicians can remind patients and parents that epinephrine is weight-based, and once a child weighs 30 kg (66 lbs), the dose needs to increase from 0.15 mg to 0.3 mg.43
The CDC maintains a site that lists products containing α-gal, such as gelatin, glycerin, magnesium stearate, and bovine extracts, which provides a tool to manage the condition. Pharmacy staff may direct patients to this site.
Finally, pharmacists and technicians need to remember that all tick-borne diseases are zoonotic diseases. Zoonotic diseases are transmitted from animals to humans, so people who own companion animals, especially dogs, need to be vigilant about ticks.44 In the United States, dog owners are notorious for skimping on flea and tick preventive treatments or using natural remedies when medications are much more effective. In a typical year, the majority of owners purchase only seven months of preventive medications; their dogs are unprotected for five months of the year.44 Owners need to ensure their dogs are on an effective tick preventive year-round (some owners mistakenly think they can stop the preventive in the colder months; that is a bad idea).44
Summary
As noted in our introduction, tick-borne diseases are on the uptick. Researchers are learning more about the various types of tick-borne diseases, the ticks most likely to cause them, and the geographic areas most affected. As noted in Table 1, a total of 12 tick-borne diseases appear in humans. Some of them have no current treatments. It is likely that researchers will identify additional tick-borne diseases in the future, and they may find effective treatments for the four diseases discussed above, as well as for alpha-gal syndrome. In the pharmacy, pharmacists and pharmacy technicians will do well to maintain a high index of suspicion for these diseases and to differentiate among the various types.
References
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Centers for Disease Control and Prevention. Ticks. About Ticks and Tickborne Disease. CDC. May 15, 2024. Accessed March 9, 2025. https://www.cdc.gov/ticks/about/index.html
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The information provided in this course is general in nature, and it is solely designed to provide participants with continuing education credit(s). This course and materials are not meant to substitute for the independent, professional judgment of any participant regarding that participant’s professional practice, including but not limited to patient assessment, diagnosis, treatment, and/or health management. Medical and pharmacy practices, rules, and laws vary from state to state, and this course does not cover the laws of each state; therefore, participants must consult the laws of their state as they relate to their professional practice.
Healthcare professionals, including pharmacists and pharmacy technicians, must consult with their employer, healthcare facility, hospital, or other organization, for guidelines, protocols, and procedures they are to follow. The information provided in this course does not replace those guidelines, protocols, and procedures but is for academic purposes only, and this course’s limited purpose is for the completion of continuing education credits.
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