Evidence Based Strategies: Along With Spring Comes the Ticks: A Brief Overview of Tickborne Diseases

Column Author:  Nicole Neeley, MD | Pediatric Resident PGY 2

Column Editor:  Kathleen J. Berg, MD, FAAP | Medical Director, Office of Evidence-Based Practice

In the United States, the incidence of tickborne illness is increasing, and geographic distributions of disease-carrying ticks are expanding. Lyme disease alone accounts for an estimated 476,000 new infections, with health care costs of anywhere from $345 to $968 million annually. This figure, though, does not account for the other common tickborne diseases within the U.S.: Rocky Mountain spotted fever/spotted fever rickettsioses (RMSF/SFR), ehrlichiosis, anaplasmosis, babesiosis and tularemia. Delay in diagnosis and treatment of these tickborne illnesses can increase the risk for severe complications such as disseminated intravascular coagulation, meningitis, encephalitis, and even increased mortality, so prompt recognition and treatment is vital when caring for these patients.

Signs and symptoms of tick-borne illnesses are often nonspecific.⁴ Patients may present with fever, headache, myalgias, or nausea. Rashes can also be a common sign; however, a rash is not present in every affected patient, so while its presence may be useful in aiding diagnosis its absence should not exclude the possibility of tick-borne disease. Given the lack of specificity of symptoms, taking a detailed history is important. Risk factors for tick-borne illnesses include time of year, with most tick-borne illness occurring between April and October⁵; as well as location. Clinicians must consider where the patient lives, as well as any recent travel. Within the Kansas City area, ehrlichiosis, RMSF/SFR, and tularemia are especially common.¹ Additionally, asking about outdoor activities or any known tick exposures help in determining the level of concern for tick-borne illness.

As with the symptoms, the physical exam may be nonspecific. If a rash is present, however, it can help distinguish between some of these tick-borne diseases. RMSF/SFR is associated with a macular rash, often starting at the wrists or ankles, before spreading and later turning petechial.⁶ Lyme disease is associated with the erythema migrans rash, often described as a “bulls-eye” lesion, and its presence alone is  enough to diagnose in those who have been in a Lyme endemic area.⁶ Ehrlichiosis and anaplasmosis may cause nonspecific maculopapular rashes that typically start on the trunk, although less frequently than Lyme or RMSF/SFR.⁶ Babesiosis is not often associated with any particular rashes or skin findings, but occasionally splenomegaly may be present.⁶ Tularemia is also not typically associated with a rash, but generally manifests with lymphadenopathy with or without ulceration at the site of the tick bite.⁶

Initial laboratory evaluation for tick-borne illness often shows thrombocytopenia, mild hyponatremia, and/or elevated ALT/AST.⁵ Within the Kansas City area, RMSF and ehrlichiosis can be difficult to distinguish clinically; so if they are suspected, disease specific testing is recommended. These labs include: RMSF IgG and IgM, Ehrlichia antibody panel, and Ehrlichia serum PCR. However, the final interpretation of serology is based on convalescent titers obtained 2-6 weeks after symptom resolution in RMSF and 2-4 weeks after initial serology in ehrlichiosis^7,8, meaning that a definitive diagnosis may be delayed by weeks. PCR tests are also often send out labs taking several days, and a negative PCR test does not fully rule out disease as the ability to identify Ehrlichia in the blood stream diminishes rapidly once therapy is started.^7,8 Therefore, given the risks of delaying or missing the diagnosis, treatment should be started empirically with doxycycline for children of all ages. Clinicians can refer to the Children’s Mercy Clinical Pathway at Tickborne Illness | Children's Mercy Kansas City for recommendations on testing for other tick-borne illnesses. This pathway also includes maps of endemic regions, photos of ticks for species identification, dosing of doxycycline, and other helpful information.

It is also important to counsel patients and families on how to protect themselves during the upcoming tick-active months. Parents and children can reduce their risk of contracting a tick-borne disease by:⁹

• Wearing long sleeves and pants when engaging in outdoor activities.
• Using appropriate bug sprays such as DEET or picaridin, or wearing permethrin treated clothing.
• Checking for ticks and showering quickly after engaging in outdoor activities.

If a tick is found on a child’s body, it should be removed by carefully grabbing the tick as close the skin as possible with fine-tipped tweezers and gently but steadily pulling back until the tick is removed.¹⁰ Skin should then be cleaned, and families should monitor for any of the signs or symptoms as previously discussed and seek medical care if needed.

References

1. Geographic Distribution of Tickborne Disease Cases. Centers for Disease Control and Prevention. (2024, May 15). https://www.cdc.gov/ticks/data-research/facts-stats/geographic-distribution-of-tickborne-disease-cases.html
2. The Impacts of Climate Change on Human Health in the United States: A Scientific Assessment. Beard, C.B., R.J. Eisen, C.M. Barker, J.F. Garofalo, M. Hahn, M. Hayden, A.J. Monaghan, N.H. Ogden, and P.J. Schramm, 2016: Ch. 5: Vectorborne Diseases. U.S. Global Change Research Program, Washington, DC, 129–156. http://dx.doi.org/10.7930/J0765C7V
3. 3. Hook SA, Jeon S, Niesobecki SA, et al. Economic Burden of Reported Lyme Disease in High-Incidence Areas, United States, 2014-2016. Emerg Infect Dis. 2022;28(6):1170-1179. doi:10.3201/eid2806.211335
4. 4. Pace EJ, O'Reilly M. Tickborne Diseases: Diagnosis and Management. Am Fam Physician. 2020;101(9):530-540
5. Read JS. Tickborne Diseases in Children in the United States. Pediatr Rev. 2019;40(8):381-397. doi:10.1542/pir.2018-0304
6. Eilbert W, Matella A. Tick-Borne Diseases. Emerg Med Clin North Am. 2024;42(2):287-302. doi:10.1016/j.emc.2024.01.004
7. Ehrlichia, Anaplasma, and Related Infections (Human Ehrlichiosis, Anaplasmosis, and Related Infections Attributable to Bacteria in the Family Anaplasmataceae). In: Red Book: 2024–2027 Report of the Committee on Infectious Diseases. 33rd ed. American Academy of Pediatrics; 2024:361-365.
8. Rocky Mountain Spotted Fever. In: Red Book: 2024–2027 Report of the Committee on Infectious Diseases. 33rd ed. American Academy of Pediatrics; 2024:727-730.
9. McFee RB. Tick vectors and tick borne illnesses overview. Dis Mon. 2018;64(5):175-180. doi:10.1016/j.disamonth.2018.01.004
10. Tick bite: What to do (CDC Publication No. CS310465-A). Centers for Disease Control and Prevention. (2021). U.S. Department of Health and Human Services, Centers for Disease Control and Prevention. https://cdc.gov/ticks/pdfs/FS_TickBite-508.pdf