Health Assessment
Lyme Disease
Colleen Burgoyne, DNP, RN, FNP-BC
Case Study
Chief Complaint
Mom states that the patient has a large red rash on the right leg.
Patient Profile
Name: Natasha Rostov
Age: 6 years old
Gender: female
History of Present Illness
Natasha is a 6-year-old girl whose mom first noticed the red mark on her daughter’s right leg yesterday evening when she was helping Natasha bathe before bed. It is on the lateral aspect of the right thigh and was about 5 cm in diameter yesterday but has expanded to 8 cm in diameter this morning. Natasha denies any pain or itching associated with the lesion. The patient and her mom deny any trauma to the area. Natasha denies any fevers or chills. She had good energy and appetite and was able to participate in all of her usual activities, including attending her summer camp.
When asked about insect bites, Natasha reports that she had a “bug on her hip” last weekend, which she spent at her father’s house. She recalls that he had to use “scissors” to get the bug off her. Natasha’s mom had not been aware of this occurrence until now. Natasha’s father lives in a more rural area, and Natasha often walks through a series of trails that he has mowed through a meadow of wildflowers and long grass on the back of his property.
Medical History
Eczema
Medications
Triamcinolone acetonide 0.025% cream, apply to areas of atopic dermatitis twice/day for up to 14 days when needed.
Social History
Natasha’s parents are divorced and have shared custody of her and her older sister. Her father lives in a home in a rural area just outside of the suburb where Natasha’s mother lives. Her father has a pet dog at his home, an 8-year-old Labrador retriever. There are no pets at Natasha’s mother’s home. Natasha will be entering first grade at the public school for her town at the end of the summer. She is doing well in school and especially enjoys science.
Both parents are non-smokers.
Family History
- Mother: healthy
- Father: healthy
- Sister (older): healthy
- Maternal grandmother: deceased from stroke, colon cancer
- Maternal grandfather: hypertension, macular degeneration, rheumatoid arthritis
- Paternal grandfather: prostate cancer, hypertension, diabetes mellitus
Review of Systems
- General: No major illness and no recent trauma or injury. Denies fevers, chills, night sweats, malaise, fatigue, and weight loss.
- Skin: Flat, erythematous lesion on upper right leg as described in HPI. No other rashes or lesions.
- HEENT: Denies headaches. Denies vision changes, itchiness, or discharge from eyes. Denies ear pain or difficulty hearing. Denies rhinitis or congestion. Denies sore throat, lesions in mouth, and frequent coughing.
- Neck: Denies neck stiffness and lumps in the neck.
- Respiratory: Denies cough, shortness of breath, and wheezing.
- Cardiovascular: Denies chest pain, syncope, pre-syncope, and palpitations.
- Gastrointestinal: Mom and child report that appetite is good. She eats a variety of foods, including fresh fruits and vegetables; has had no recent dietary changes; reports regular bowel movements; and denies pain with bowel movements, diarrhea, nausea, and vomiting.
- Urinary: Denies pain with urination or increased frequency of urination. No recent issues with incontinence.
- Genital: No concerns.
- Musculoskeletal: Denies any recent trauma. Denies any swollen, red, or painful joints.
- Neurological: Mom reports that coordination and strength seem to be appropriate for her age. No weakness, seizures, headaches, or syncope.
- Psychiatric: No recent concerns with mood. She enjoys attending summer camp and has several close friends at school.
Physical Assessment
Vitals
- Heart rate: 95 bpm
- Blood pressure: 88/52 mm Hg
- Respiratory rate: 22 bpm
- Temperature: 98.7°F (auditory measurement)
- Height: 44 in (3 ft 8 in)
- Weight: 42 lbs (19.1 kg)
General Survey
Well-appearing 6-year-old girl. Natasha is energetic and interactive. She interacts with her mother often throughout the appointment, often looking to her for reassurance. Her clothes appear clean and are appropriate for the summer season. She appears well-groomed with clean hair, pulled neatly into a ponytail. No foul odors detected.
- Skin: Flat, erythematous, annular, lesion on the lateral aspect of the right thigh, measures 8 cm in diameter. There is an area of clearing around a central macule about 2 cm in diameter. The area of clearing is then surrounded by a larger annular rash about 8 cm in diameter (see figure 1). No other skin lesions or rashes.
- HEENT:
- Head: Atraumatic, normocephalic, no lesions. Hair is normally distributed.
- Eyes: Pupils 4 mm bilaterally with bilateral and equal reaction to light and accommodation. Red light reflex intact. Optic disc margins are sharp, no hemorrhages or AV nicks.
- Ears: No deformity of external structures. No tenderness of palpation of the pinna or tragus bilaterally. External canals are clear of debris and drainage, with only a minimal amount of amber cerumen observed. TM are intact and with visible light cone bilaterally.
- Nose: Septum is midline and nasal mucosa are pink and moist with no lesions. No drainage detected.
- Mouth: Permanent teeth erupting in the upper central incisor locations. No visible caries, tooth decay, or broken teeth. Oral mucosa are pink, moist, and intact with no lesions. Tonsils are partially visible bilaterally; no exudate or lesions.
- Neck: Supple; trachea is midline; no lymphadenopathy; thyroid not palpable.
- Lungs: Breathing appears unlabored with no use of accessory muscles. Lung sounds are clear to auscultation bilaterally.
- Cardiovascular: A grade 2 murmur is heard at the left lower sternal border. It is a systolic murmur with a crescendo-decrescendo pattern. Intensity is increased in the supine position. No edema of extremities.
- Heart rate is 95 bpm and is in normal sinus rhythm on electrocardiogram (ECG).
- Abdomen: Slightly protuberant, soft, non-tender. Bowel sounds present in all quadrants. Liver span is 4 cm below the right costal margin and is non-tender. Spleen and kidneys not palpable.
- Genital: Tanner 1 female genitals. No lesions or discharge observed.
- Musculoskeletal: No swollen or erythematous joints. Full range of motion in joints of upper and lower extremities bilaterally. Spine is straight and non-tender. Gait is coordinated. 5/5 strength of upper and lower extremities.
- Neurological: Alert, inquisitive, interactive, and attentive throughout the appointment. Language is clear and coherent and demonstrates an age-appropriate level of understanding and abstraction. Deep tendon reflexes are +2 in the biceps, patellar and Achilles locations bilaterally.
Based on the presence of the erythema migrans rash in a patient with epidemiological risk of exposure to Borrelia burgdorferi, such as living in an endemic area, Natasha is diagnosed with early Lyme disease. On account of her characteristic presentation and strong epidemiological connection, serological testing is not necessary to establish the diagnosis. In fact, obtaining serological testing in this case may actually complicate the clinical picture because of a substantial risk of false negative results. False negative results are likely during early infection because for many people, the immune system has not yet had sufficient time to develop IgG antibodies against B. burgdorferi.
Treatment Plan
Amoxicillin: 50 mg/kg/day orally divided 3 times daily (maximum 500 mg per dose) for 14 days
Comment on treatment selection
Treatment options for early Lyme disease in children are amoxicillin, doxycycline and cefuroxime. Use of doxycycline for children < 8 is supported by the American Academy of Pediatrics, as long as the duration is ≤ 21 days. However, there is limited data on the safety of doxycycline in children (AAP, 2024; Meissner & Steere, 2022).
The decision of whether to use doxycycline or an alternative should be based on whether there is evidence of the neurological system being affected by the infection and/or if there is concern for coinfection with anaplasma phagocytophilum or ehrlichia muris. Doxycycline is the preferred agent if there is concern for neurological involvement or coinfection because the alternative agents have demonstrated efficacy in treating neurological infection and do not have activity against anaplasma phagocytophilum or ehrlichia muris (Meissner & Steere, 2022).
In the case of Natasha, she has no signs or symptoms to indicate neurological involvement in the infection and no signs or symptoms consistent with coinfection with anaplasma phagocytophilum or ehrlichia muris.
| Agent | Dose | Comment |
|---|---|---|
| Doxycycline | 4.4 mg/kg/day orally divided twice daily (maximum 100 mg per dose) for 10 days | Children ≥ 8 years:
Doxycycline is the first line agent. |
| Children <8
Doxycycline is the preferred agent if there is concern for neurological involvement or coinfection with Anaplasma phagocytophilum or Ehrlichia muris Use of doxycycline for children <8 is supported by the American Academy of Pediatrics, as long as the duration is ≤ 21 days. However, the data on safety is limited, so it is reasonable to use an alternative if there is not concern for neurological involvement or coinfection |
||
| Amoxicillin | 50 mg/kg/day orally divided 3 times daily (maximum 500 mg per dose) for 14 days | Not effective concern for neurological involvement or coinfection with Anaplasma phagocytophilum or Ehrlichia muris |
| Cefuroxime | Cefuroxime 30 mg/kg/day orally divided twice daily (maximum 500 mg per dose) for 14 days | Not effective concern for neurological involvement or coinfection with Anaplasma phagocytophilum or Ehrlichia muris |
Review Questions
Click the arrow to expand the section and view the correct answers.
- Select the 3 best choices from the list below to create a differential diagnosis for this patient.
- Cellulitis
- Psoriasis
- Pityriasis rosea
- Lyme Disease
- Celiac Disease
- Tinea corporis
- Lead poisoning
Answer:
A. Cellulitis
Feedback:
Cellulitis is a bacterial infection of the skin and soft tissue without a suppurative focus. The clinical presentation of cellulitis is characterized by acute onset of a localized area of erythema, edema, and warmth of the skin. Although cellulitis is typically associated with systemic symptoms, as well as fever, chills, and/or malaise, it is a good choice to include in the differential for this patient because of the characteristics of her skin lesion.
Psoriasis is a common skin disorder which often starts during childhood. Risk for psoriasis is influenced by genetic and environmental factors. The presentation of Natasha in the case does not fit well with psoriasis, which usually presents with multiple lesions with a symmetric distribution. Additionally, the skin lesions of psoriasis are typically plaques, which are raised, round, brightly erythematous, and covered with a silvery scale (Paller & Broun Lund, 2025).
Pityriasis rosea is an acute, self-limited skin eruption that is hypothesized to be caused by a viral etiology. Typically, the skin eruption is preceded by a prodrome of headache, malaise, and pharyngitis. This is followed by the appearance of a “herald patch,” a single, sharply demarcated skin lesion on the chest, neck, or back that is usually oval-shaped and about 2-5 cm in diameter. Soon after it appears, the herald patch develops a collarette of scale and begins to clear centrally. As the herald patch disappears, multiple oval lesions that are similar in appearance to the herald patch but smaller in size appear in groupings on the trunk and proximal areas of the extremities. The lesions are often pruritic (Goldstein & Goldstein, 2023). The patient in the case study does not fit well with the typical presentation of pityriasis rosea, given the lack of prodrome and the non-pruritic nature of her lesion. Also, the skin lesion on Natasha is in a location that would be atypical for pityriasis rosea, is larger, and lacks the scaliness of a resolving herald patch.
The presentation described in the case study is consistent with the erythema migrans rash of Lyme disease. Additionally, the patient has epidemiological risk factors for Lyme disease, including living in an endemic region during the warm months and exposure to outdoor areas with long grass.
The patient presentation in the case study is not consistent with Celiac disease. Although Celiac disease can have a wide range of clinical manifestations, typically there are signs of poor weight gain or growth or weight loss along with prominent gastrointestinal symptoms, such as abdominal pain, abdominal bloating, vomiting, persistent diarrhea, and constipation. Celiac disease can sometimes cause a skin rash, which is called dermatitis herpetiformis and is characterized by a pruritic papulo-vesicular cluster of skin lesions, which usually occur symmetrically (Stahl & Liu, 2024). This is not consistent with the single macular lesion of the patient in the case study.
Tinea corporis refers to dermatophyte infection of the skin, hair, and nails on body surfaces other than the feet, groin, face, or scalp. Dermatophytes are filamentous fungi that are able to consume keratin in the skin, hair, and nails for nourishment. Tinea corporis presents with an annular (ring-shaped) plaque with a raised border, often with scaling and pruritus. There can be a single lesion or multiple lesions (Goldstein, 2024). It is reasonable to include this diagnosis in the differential because the annular shape is consistent, though the lack of a raised border, scaling, and pruritus makes this diagnosis less likely.
- Assessment of the epidemiological risk of exposure to Borrelia species is critical to evaluating a patient for Lyme disease. In the presented case, we determined that Natasha had a high epidemiological risk of exposure. Which of the following factors would change her epidemiological risk such that Lyme disease would no longer be a likely diagnosis?
- If the case presentation occurred in the middle of winter
- If this case occurred in one of the Southern states such as Florida.
- If the patient’s age was 20-25 years old
- If the patient were of a non-Caucasian race
- ‘A’ and ‘B’
- ‘C’ and ‘D’
Answer:
E. ‘A’ and ‘B’
Feedback:
The correct answer is choice ‘E’. Choices ‘A’ and ‘B’ would both make the acquisition of Lyme disease epidemiologically unlikely. Seasonality is an important factor in Lyme disease acquisition. People are most likely to acquire the infection when the nymphal form of the tick vector is most active, which occurs during the spring and summer in the United States. Since the incubation period for Lyme disease is approximately 2 to 3 weeks, early Lyme presentations would be expected from late spring through early fall. A midwinter presentation of early Lyme disease is unlikely, as it is unlikely that a person would have been bitten by a tick vector during the preceding 2-3 weeks. It is important to remember that late Lyme disease can present at any time throughout the year (Mead, 2025).
Geography is a factor in the epidemiology of Lyme disease because human acquisition occurs only in areas where the tick vector lives. In the United States, the vast majority of Lyme disease cases occur in the northeastern states, Wisconsin and Minnesota (Mead, 2025).
Although the distribution of Lyme disease in the United States is bimodal with peaks among children 5 to 14 years old and adults over 50 years old, all age groups are affected. The heightened risk among certain age groups likely reflects behavioral factors, such as time spent outdoors in forested areas (Mead, 2025).
Race is not an independent factor in the risk of Lyme disease acquisition, which is based on the likelihood that a person has come into contact with an infected tick vector. This risk is influenced by geography, seasonality, and how much time a person spends outdoors in forested areas (Mead, 2025)
- Fortunately, Natasha is being treated for Lyme disease during the early localized stage. This will prevent progression to late Lyme disease. Which of the following is the most common manifestation of late Lyme disease in children?
- Myalgic encephalitis/chronic fatigue syndrome
- Monoarticular arthritis
- Facial nerve palsy
- Meningitis
Answer:
B. Feedback:
If early Lyme disease is not recognized and treated, some patients can develop late Lyme disease weeks to months after the initial infection. Late Lyme disease most commonly manifests as arthritis. Typically, Lyme arthritis is monoarticular, with the knee joint being most commonly affected (Shapiro, 2024).
Myalgic encephalitis/chronic fatigue syndrome (ME/CFS), which was previously known as chronic fatigue syndrome is a poorly understood syndrome which encompasses a range of presentations characterized by severe fatigue. Although ME/CFS onset is sometimes triggered by an acute infectious illness like Lyme disease, there is no evidence that this syndrome is a result of ongoing, active infection with B.burgdorferi (Gluckman, 2025; Shapiro, 2024).
Facial nerve palsy is a well-described neurological manifestation of early disseminated Lyme disease, which can occur 2-8 weeks after the initial tick bite and Lyme acquisition if early localized disease is not recognized and treated. During early disseminated Lyme, B. burgdorferi enters the bloodstream and disseminates through the body with the potential to affect the central nervous system and heart. In addition to facial nerve palsy, other manifestations of early disseminated Lyme disease in children include multiple erythema migrans lesions, meningitis, and carditis. The facial nerve palsy of early disseminated Lyme usually resolves completely with or without treatment; however, treatment with antibiotics is still needed to prevent progression to late Lyme disease (Shapiro, 2024).
- Review the findings of the cardiovascular exam for Natasha and select the correct interpretation of the findings.
- The murmur is a clinical manifestation of Lyme carditis
- The murmur is a clinical manifestation of endocarditis with B. burgdorferi
- The murmur is concerning for co-infection with Babesia microti, a protozoal organism
- The murmur is consistent with a physiologic or “innocent” murmur
- The murmur indicates that Natasha has a history of congenital heart disease
Answer:
D. The murmur is consistent with a physiologic or “innocent” murmur
Feedback:
The murmur described in the physical exam section of the case study is consistent with a physiologic or “innocent” murmur. These benign murmurs are common during childhood, with an estimated 80% of children having a physiologic murmur at some point. Physiologic murmurs are caused by normal blood flow through normal cardiac structures, as opposed to the turbulent blood flow caused by abnormalities in cardiac structures, which causes pathologic murmurs (Newcombe, 2025).
Lyme carditis is a rare manifestation of early disseminated Lyme disease in children. However, Lyme carditis is characterized by complete heart block or partial atrioventricular block (Shapiro, 2024). These conduction abnormalities can alter the cardiac rhythm but would not be expected to cause a heart murmur. B. burgdorferi is not a cause of endocarditis.
Babesia microti is a protozoan which can infect mammals, including humans and cause lysis of the host’s red blood cells. Babesia microti is the causative agent of babesiosis in the United States and is now endemic to the Northeast and upper Midwest regions. Similar to B. burgdorferi, B. microti is transmitted to humans via a tick vector, specifically the Ixodes scapularis tick. The incubation period after inoculation is 1-4 weeks. The clinical manifestations of babesiosis range from asymptomatic to severe illness, with severe illness largely restricted to older and/or immunocompromised patients. Mild to moderate babesiosis is characterized by gradual onset of fatigue and malaise with fever. Splenomegaly and/or hepatomegaly may be observed on physical examination. In contrast to Lyme disease, babesiosis rarely causes a rash. Babesiosis is strongly associated with the following laboratory findings: (1) anemia, (2) elevated lactate dehydrogenase, (3) low haptoglobin, (4) reticulocytosis and (5) thrombocytopenia. Additional laboratory abnormalities can include elevated liver enzymes and alkaline phosphatase, elevated total and indirect bilirubin, elevated blood urea nitrogen, and elevated serum creatinine (Krause & Vannier, 2024).
B. microti can be transmitted to humans along with other pathogens carried by the Ixodes scapularis tick which include B. burgdorferi, Anaplasma phagocytophilum or Ehrlichia muris. Patients who have been diagnosed with Lyme disease should be evaluated for coinfection with the pathogens listed above if the clinical presentation is atypical or there is lack of response to standard antibiotic therapy (Krause & Vannier, 2024).
Clinical Pearls
Lyme disease should be suspected in patients who are: (1) at risk of exposure to ticks and (2) have clinical manifestations consistent with Lyme disease. See Tables 2 and 3 for when to consider Lyme disease.
Situations in Lyme testing are not warranted:
- Screening of asymptomatic patients who live in endemic areas
- For evaluation of patients who present only with nonspecific symptoms
| Residence in or travel to an endemic area | United States:
|
|
|---|---|---|
Europe:
|
||
| Seasonality |
|
|
| High-risk hobbies/occupations |
|
|
| Early disease | Early localized disease: occurs within a few days to one month after tick bite |
|
|---|---|---|
| Early disseminated disease: occurs weeks to months after tick bite |
|
|
| Late disease: occurs months to years after the tick bite |
|
|
| Clinical Presentation | Recommended Testing | Notes |
|---|---|---|
| Erythema migrans | Diagnosis should be made on clinical grounds alone when at least one characteristic EM lesion is present in a patient who lives in or has recently traveled to an endemic area |
|
| Early disseminated and late Lyme | Serological testing is recommended.
Note that serological testing is an adjunct to the clinical diagnosis. Serological testing alone can neither establish nor exclude the diagnosis of Lyme. |
Two-tier testing method is most commonly used:
|
| Lyme arthritis (suspected) | PCR testing of the synovial fluid is recommended | |
| Suspected Lyme disease affecting the central nervous system | Simultaneous samples of CSF and serum can be obtained to determine the CSF/serum antibody index |
| Step 1: Enzyme Immunoassay | Step 2: Western blot | Interpretation | |
|---|---|---|---|
| IgG | IgM | ||
| Negative | N/A | N/A | Western blot not performed
Diagnosis of Lyme disease is unlikely |
| Positive | Positive | Positive | Supports a diagnosis of Lyme disease. Staging depends on clinical picture |
| Positive | Positive | Negative | Supports a diagnosis of late Lyme disease if the clinical picture correlates |
| Positive | Negative | Positive | This could be consistent with early disseminated Lyme. However, the IgM test is prone to false positives. A serology with an isolated positive IgM cannot be used to support a diagnosis of late Lyme disease. A positive IgM response alone should not support the diagnosis of Lyme disease if symptoms have been present for more than four weeks, since the majority of patients will have a positive IgG Western blot after that time. |
| Positive | Negative | Negative | Rarely, patients can have a negative IgM and IgG in early Lyme. This is most likely to occur in those who present with multiple EM, which can occur quickly after the patient is infected. In this scenario, some patients may be treated empirically (eg, those with multiple EM from an endemic area). If empiric treatment is not pursued, serology testing should be repeated about 3 weeks later. |
References
American Academy of Pediatrics. (2024). Red book: 2024-2027 Report of the committee on infectious diseases (33rd ed.) American Academy of Pediatrics.
Bickley, L. S. (2024). Bates’ guide to physical examination and history taking (13th ed.). Wolters Kluwer.
Gluckman, S. J. (2025). Clinical features and diagnosis of myalgic encephalomyelitis/chronic fatigue syndrome. UpToDate. Retrieved May 30, 2025 from https://www.uptodate.com/contents/clinical-features-and-diagnosis-of-myalgic-encephalomyelitis-chronic-fatigue-syndrome
Goldstein, A. O. (2024). Dermatophyte (tinea) infections. UpToDate. Retrieved May 28, 2025 from https://www.uptodate.com/contents/dermatophyte-tinea-infections
Goldstein, A. O. & Goldstein, B. G. (2023). Pityriasis Rosea. UpToDate. Retrieved May 22, 2025 from https://www.uptodate.com/contents/pityriasis-rosea
Hu, L. (2024). Treatment of Lyme disease. UpToDate. Retrieved May 22, 2025 from https://www.uptodate.com/contents/treatment-of-lyme-disease
Krause, P. J. & Vannier, E. G. (2024). Babesiosis: Clinical manifestations and diagnosis. UpToDate. Retrieved June 1, 2025 from https://www.uptodate.com/contents/babesiosis-clinical-manifestations-and-diagnosis
Mead, P. (2025). Epidemiology of Lyme disease. UpToDate. Retrieved May 22, 2025 from https://www.uptodate.com/contents/epidemiology-of-lyme-disease
Meissner, H.C., & Steere, A.C. (2022). Management of pediatric Lyme disease: Updates from 2020 Lyme guidelines. Pediatric Perspectives, 149(3), e2021054980. https://doi.org/10.1542/peds.2021-054980
Newcombe, J. (2025). Cardiovascular disorders. In Garzon, D. L., Dirks, M., Driessnack, M., Duderstadt, K.G., & Gaylord, N. M. (Eds.), Pediatric primary care (8th ed., pp 536-565). Elsevier.
Paller, A. S. & Broun Lund, E. (2025). Psoriasis in children: Epidemiology, clinical manifestations, and diagnosis. UpToDate. Retrieved May 21, 2025 from https://www.uptodate.com/contents/psoriasis-in-children-epidemiology-clinical-manifestations-and-diagnosis
Shapiro, E. D. (2024). Lyme disease: Clinical manifestations in children. UpToDate. Retrieved May 21, 2025 from https://www.uptodate.com/contents/lyme-disease-clinical-manifestations-in-children
Stahl， M. & Liu， E. (2024). Epidemiology， pathogenesis， and clinical manifestations of celiac disease in children. UpToDate. Retrieved April 25, 2026 from https://www.uptodate.com/contents/epidemiology-pathogenesis-and-clinical-manifestations-of-celiac-disease-in-children
Media Attributions
- Lyme 9875 © James Gathany/ CDC is licensed under a Public Domain license
characterized by forming and discharging pus
Large (>10mm), raised, thickened, and often-scaly patches on skin. With lyme disease, these are erythema migrans lesions that expand, sometimes, but not always, in a bulls-eye pattern.
affecting only one joint
A category of microscopic single-cell organisms that are eukaryotic by virtue of having a membrane-bound nucleus. Many clinically relevant protozoa are parasites.
low red blood cells or a low serum hemoglobin concentration
An increase in the amount of reticulocytes in the circulating blood. Reticulocytes are an immature form of red blood cells. Reticulocytosis is an indication of blood regeneration, often in response to the loss of red blood cells through hemolysis or blood loss.
