Tick-borne illnesses are increasing in prevalence and geographic reach. Because the presentation of these illnesses is sometimes nonspecific, they can often be misdiagnosed, especially in the early stages of illness. A detailed history with questions involving recent activities and travel and a thorough physical examination will help narrow the diagnosis. While some illnesses can be diagnosed on clinical findings alone, others require confirmatory testing, which may take days to weeks to result.
Please review the risk management pitfalls below to avoid unwanted outcomes when treating pediatric patients with tick-borne illnesses.
1. ?There was no history of a tick bite, so I don?t have to worry about tick-borne illnesses.?
Tick bites are often painless and may be in locations that are not easily visible. Patients may not give a history of a tick bite; therefore, a careful history to elicit risk factors for tick exposure is necessary, particularly in endemic areas. In studies of tick-borne illnesses, a history of a tick bite was not reported in 30% to 40% of confirmed cases.
2. ?It?s not the summer, so this patient cannot have a tick-borne illness.?
Most tick-borne illnesses have a seasonal variation, with most cases presenting in the summer months. However, due to variable incubation periods and weather pattern variations, seasonal exclusion alone is not reliable to exclude a tick-borne illness. Cases of RMSF, anaplasmosis, and ehrlichiosis have been reported during all months of the year, particularly in milder southern climates.
3. ?I did not examine the skin on my patient with ascending paralysis, as the history was most consistent with Guillain-Barr?.?
Ticks may often be hidden in difficult-to-find places, including the hair and groin. Neglecting to complete a thorough skin examination, particularly in endemic areas during high tick season, may subject patients to unnecessary and invasive testing and treatments, in addition to the potential for respiratory failure.
4. ?I had a strong suspicion that my patient had a tick-borne illness, but I wanted to be sure, so I waited for the confirmatory tests to result before starting her on an antimicrobial.?
For most tick-borne illnesses, confirmatory testing may take days or weeks to result. In patients with a consistent history, examination, and preliminary laboratory findings, empiric treatment may be started while test results are pending. In particular, delayed treatment with doxycycline is associated with a higher mortality rate for RMSF. Untreated, RMSF has a case fatality rate of 10% to 25%.
5. ?I treated my 5-year-old patient with Rocky Mountain spotted fever with chloramphenicol because of the risk of teeth-staining with doxycycline.?
Unless a patient has an anaphylactic reaction to doxycycline, the treatment of choice for patients with a rickettsial disease is doxycycline, regardless of age. In a survey study of clinical practitioners, 80% of practitioners correctly identified doxycycline as treatment for RMSF in children aged > 8 years, while only 35% chose doxycycline for children aged < 8 years. This is similar to findings from other studies.
6. ?I strongly suspected my patient had Lyme arthritis, so I didn?t need to cover for other etiologies.?
Tick-borne illnesses often mimic other serious diseases. Of these, bacterial meningitis, septic joint, and sepsis are among the diseases with higher morbidity. Given that the testing for tick-borne diseases takes time to result, in severely ill patients, treatment for both tick-borne illnesses and other bacterial infections should be started until confirmatory testing is completed.
7. ?Most patients already know how to prevent tick bites, so I don?t need to counsel them.?
Preventive behaviors can be effective means to decrease the incidence of tick-borne diseases. Checking for ticks within 36 hours of potential exposure and bathing within 2 hours of spending time outdoors have been shown to be protective against Lyme disease. Other recommendations include wearing protective clothing and applying tick repellent, though the studies are mixed on the effectiveness of these preventive measures.
8. ?I suspect my patient has Rocky Mountain spotted fever, but he doesn’t have a petechial rash, so that can’t be the diagnosis.?
Petechial rash may not develop in all patients, and a small percentage of patients will not develop a rash. Some studies report as many as 95% of patients will develop a rash, though a retrospective study in Arizona reported lower rates, with only 68% of confirmed cases having had a rash. Of those that do develop a rash, up to 60% may not become petechial.
9. ?The patient has a dog, but no other risk factors, so a tick-borne illness is unlikely.?
Household pets, and dogs in particular, can be a significant risk factor for tick exposure in endemic areas. Dogs may pick up ticks more easily or be more likely to play in areas with tall grass, bringing ticks into the home as a source of exposure. Contact with dogs is associated with exposure to ticks and cases of tick-borne illness. Preventive measures, such as frequently examining dogs for ticks and use of tick repellent on pets, are recommended to decrease this exposure.
10. ?I?m not in a high-risk area, so I don?t need to consider tick-borne illnesses in my differential.?
While there are areas that are highly endemic for certain diseases, tick-borne illnesses have been reported in all of the contiguous 48 states. A thorough travel history is critical to identifying possible tick exposures, as cases acquired during travel to endemic areas may be easily missed. Patients may also be exposed during international travel. Excluding a specific disease based solely on geographic location may delay diagnosis and increase the risk of developing complications.
Need more information on the topic? Check out the Tick-Borne Illnesses: Identification and Management in the Emergency Department (Pharmacology CME) issue of Pediatric Emergency Practice.
Last Updated on January 25, 2023
