Anaplasma and Ehrlichia
Fever with blood-count clues
Clinicians look for CBC changes, low platelets, low white blood cells, liver enzyme elevation, fever, severe headache, muscle pain, and early PCR timing.
Tick-borne infections
Other Tick-Borne Diseases
Anaplasma, Ehrlichia, Rickettsia, Borrelia miyamotoi, Powassan virus, tularemia, and more. Geography, timing, and urgency guide testing and care when multiple infections are possible.
Illness map
A single tick bite can create several clinical possibilities.
Some tick-borne diseases can become serious quickly. This page helps patients prepare for care and recognize when urgent evaluation is appropriate.
Rickettsial illness
Rash, fever, and urgent care
High fever, severe headache, rash, confusion, and rapid worsening should be treated as urgent, especially after known tick exposure.
Borrelia miyamotoi and relapsing fever Borrelia
Relapsing fever patterns
Document fever cycles, chills, headache, body pain, geography, and whether specialized testing for relapsing fever Borrelia is available.
Powassan and neurologic infections
Neurologic red flags
Severe headache, stiff neck, confusion, seizures, weakness, or encephalitis symptoms after tick exposure need urgent medical evaluation.
Tularemia and other regional infections
Geography matters
Regional infections are matched to exposure history, animal contact, ulcers, swollen glands, pneumonia-like symptoms, and unusual fever patterns.
Comprehensive tick-borne atlas
Rare infections still belong in the differential when geography, symptoms, and labs fit.
This guide accounts for the current CDC-listed U.S. tick-borne conditions and adds a travel-aware international watch list. It is designed to help patients organize documentation for clinicians, not diagnose themselves.
U.S. tick-borne and tick-associated conditions to discuss
| Condition | Common clues | Testing and care focus | Urgency notes |
|---|---|---|---|
| Lyme disease | Expanding rash, summer flu, migrating joint or nerve pain, facial palsy, arthritis, cognitive symptoms, heart rhythm symptoms. | Timing of two-tier testing, immunoblot bands, early clinical diagnosis, co-infections, and non-tick differential diagnosis. | Facial droop, fainting, chest pain, stiff neck, confusion, or pregnancy with fever after exposure needs prompt care. |
| Anaplasmosis | Fever, chills, severe headache, muscle aches, low white blood cells, low platelets, elevated liver enzymes, usually little or no rash. | PCR in the first week, paired antibody testing, CBC, platelets, liver enzymes, sodium, and overlap with Lyme or Babesia. | Can become severe, especially with immune suppression, older age, or delayed care. |
| Ehrlichiosis | Fever, headache, muscle pain, GI symptoms, confusion, rash more often in children, low white cells, low platelets, elevated liver enzymes. | Ehrlichia species fit, lone star tick exposure, PCR timing, and paired serology when needed. | Rapid worsening, confusion, breathing trouble, kidney or liver involvement, or immune suppression needs urgent evaluation. |
| Rocky Mountain spotted fever | High fever, severe headache, GI symptoms, rash that may appear late, tick exposure in southeastern, south-central, or other endemic areas. | Clinical treatment decisions before test confirmation, platelet and sodium abnormalities, liver enzymes, and paired serology. | Medical emergency. Delayed treatment can be fatal even if early tests are negative. |
| Rickettsia parkeri rickettsiosis | Eschar at bite site, fever, headache, muscle pain, rash, Gulf Coast tick exposure. | Spotted fever group rickettsial testing, eschar swab or biopsy PCR, geography, and cross-reactive antibody results. | Usually milder than RMSF but still deserves prompt clinician assessment. |
| 364D rickettsiosis / Pacific Coast tick fever | Eschar, fever, swollen nodes, headache, fatigue, Pacific Coast tick exposure, especially in California and western regions. | Eschar sample, PCR, spotted fever group serology, and local public health guidance when available. | Seek prompt care for fever with eschar after tick exposure. |
| Babesiosis | Fever waves, chills, sweats, air hunger, fatigue, dark urine, jaundice, anemia, low platelets, elevated bilirubin or liver enzymes. | Smear, PCR, FISH, antibodies for relevant species, hemolysis labs, blood-donation guidance, and high-risk status. | Urgent with no spleen, immune suppression, pregnancy, older age, severe shortness of breath, confusion, or dark urine with weakness. |
| Hard tick relapsing fever / Borrelia miyamotoi disease | Relapsing fever, chills, headache, fatigue, body pain, sometimes neurologic symptoms, Ixodes tick exposure. | Relapsing-fever-specific testing, because standard Lyme tests may miss Borrelia miyamotoi or soft tick relapsing fever. | Severe headache, stiff neck, confusion, or immune suppression needs urgent care. |
| Soft tick relapsing fever | Recurring fever after sleeping in rustic cabins, caves, or rodent-infested buildings, often in western mountain regions. | Exposure to Ornithodoros soft ticks, fever-cycle history, blood smear during fever, PCR, and regional public health testing. | High fever, pregnancy, neurologic symptoms, or severe dehydration warrants urgent care. |
| Tularemia | Fever, skin ulcer, swollen painful lymph nodes, eye irritation, sore throat, pneumonia-like illness, tick or animal exposure. | Ulceroglandular, glandular, oculoglandular, or pneumonic forms; serology timing; PCR/culture precautions; and reporting requirements. | Can be serious. Pneumonia, high fever, or systemic illness needs prompt care. |
| Southern tick-associated rash illness | Expanding Lyme-like rash after lone star tick bite, fatigue, headache, fever, muscle or joint pain, often in southern or eastern states. | STARI versus Lyme distinction, Lyme testing when appropriate, and follow-up when symptoms persist. | Seek care for expanding rash after a tick bite, especially with fever or systemic symptoms. |
| Powassan virus disease | Fever, headache, vomiting, weakness, confusion, seizures, meningitis, or encephalitis after Ixodes tick exposure. | Urgent neurologic evaluation, CSF testing, state public health testing, and supportive care planning. | Neurologic symptoms after tick exposure are urgent. There is no routine outpatient self-treatment. |
| Bourbon virus disease | Rare illness with fever, fatigue, rash, headache, body aches, nausea, low white cells, and low platelets. | State health department testing when common tick-borne tests are negative but illness is severe. | Severe systemic illness, dehydration, confusion, bleeding, or very low blood counts needs urgent evaluation. |
| Heartland virus disease | Fever, fatigue, headache, muscle aches, diarrhea or nausea, low white cells, low platelets, and liver enzyme elevation, often linked to lone star ticks. | Public health testing, CBC trends, liver enzymes, and assessment for ehrlichiosis or other treatable infections. | Worsening weakness, dehydration, confusion, or abnormal blood counts needs prompt care. |
| Colorado tick fever | Fever, chills, headache, body aches, fatigue, sometimes biphasic fever, Rocky Mountain wood tick exposure at higher elevations. | PCR or serology through public health channels, CBC, and blood donation precautions after infection. | Usually supportive care, but severe neurologic symptoms, bleeding, or dehydration requires urgent care. |
| Alpha-gal syndrome | Delayed hives, GI distress, swelling, or anaphylaxis after mammalian meat, dairy, gelatin, or related products, often after lone star tick bites. | Alpha-gal IgE testing, allergist referral, hidden exposures, medication or gelatin risks, and emergency epinephrine planning. | Anaphylaxis, throat swelling, wheezing, fainting, or rapidly spreading hives is an emergency. |
| Tick paralysis | Ascending weakness or paralysis from an attached tick, often without fever, sometimes resembling neurologic disease. | Full scalp and skin tick check when sudden ascending weakness follows outdoor exposure. | Emergency evaluation is appropriate. Movement often improves after tick removal, but breathing risk must be assessed. |
| Bartonella / Bartonella-like illness | Foot or shin pain, swollen nodes, neuropsychiatric flares, eye symptoms, streak-like skin changes, cat/flea exposure, and possible tick exposure. | Tick transmission debate, cat or flea exposure, species-specific tests, PCR, enrichment culture, and symptom pattern. | Urgent with suicidality, seizure, eye pain with vision change, stroke-like symptoms, or severe psychiatric symptoms. |
Travel and global rare illnesses
International tick-borne diseases matter when travel, immigration, military service, field work, or animal exposure fits.
These conditions are not the usual explanation for a U.S. patient, but they matter when exposure history points outside the standard local map.
Viral and hemorrhagic illnesses
- Tick-borne encephalitis: Europe and Asia; fever followed by meningitis or encephalitis in some patients; vaccination exists in some settings.
- Crimean-Congo hemorrhagic fever: Africa, the Balkans, the Middle East, and parts of Asia; fever and bleeding risk after tick or animal exposure.
- Kyasanur Forest disease: India; fever, GI symptoms, bleeding, and neurologic complications after tick or monkey-associated exposure.
- Omsk hemorrhagic fever: parts of Russia; fever and hemorrhagic features linked to ticks and animal exposure.
Spotted fever and bacterial watch list
- Mediterranean spotted fever: fever, rash, eschar, and travel or residence around the Mediterranean basin.
- African tick-bite fever: fever, eschar, swollen nodes, and safari, farming, hunting, or field exposure in sub-Saharan Africa or the Caribbean.
- Queensland tick typhus and other regional spotted fevers: fever, rash, eschar, and location-specific exposure.
- Neoehrlichiosis, Q fever, and regional relapsing fevers: consider with compatible travel, animal exposure, immune suppression, or relapsing fever patterns.
Shared red flags across tick-borne diseases
Seek urgent medical care for high fever, rapidly worsening illness, confusion, stiff neck, severe headache, seizure, fainting, chest pain, shortness of breath, pregnancy, immune suppression, no spleen, or rash with systemic illness.
- CDC notes many tick-borne diseases share fever, chills, aches, fatigue, headache, and sometimes rash.
- Bring geography, travel, tick photos, rash photos, animal exposure, and dates of symptoms.
Recommended tests for other tick-borne diseases
| Condition group | Horowitz / Kinderlehrer clinical focus | Common tests and timing to discuss |
|---|---|---|
| Anaplasma and Ehrlichia | Fever with low white cells, low platelets, elevated liver enzymes, severe headache, and rapid onset after tick exposure should be treated as time-sensitive. | Whole-blood PCR during the first week, acute and convalescent IgG IFA, CBC with differential, platelets, CMP/liver enzymes, sodium, kidney markers, and repeat serology when early testing was negative. |
| Rickettsial illness / RMSF / spotted fevers | Horowitz and Kinderlehrer-style tick-borne workups emphasize not waiting for early negative tests when fever, rash, eschar, severe headache, or rapid worsening fits rickettsial disease. | Paired IgG IFA two to four weeks apart, PCR or immunohistochemistry from eschar/skin biopsy when available, CBC, platelets, CMP, sodium, and urgent treatment decisions before confirmatory results in high-risk presentations. |
| Relapsing fever Borrelia and B. miyamotoi | Relapsing fever patterns can be missed by standard Lyme tests; a fever-cycle timeline is often as important as the lab order. | Relapsing-fever Borrelia PCR during fever, blood smear during fever for soft-tick relapsing fever, B. miyamotoi PCR or GlpQ-based serology where available, expanded Borrelia immunoblot, CBC/CMP, and CSF evaluation if meningitis symptoms appear. |
| Tularemia and regional bacterial infections | Ulcer, swollen painful nodes, pneumonia-like illness, eye involvement, animal exposure, or tick exposure can require public-health-aware testing. | Tularemia serology with repeat titers, PCR or culture only with proper biosafety precautions, ulcer/lymph node sample guidance, chest imaging when pneumonic disease is suspected, CBC/CMP, and local health department coordination. |
| Powassan, Heartland, Bourbon, Colorado tick fever, and other viruses | Severe neurologic symptoms, low counts, hepatitis-like labs, or unexplained severe systemic illness after tick exposure should move through state public-health channels. | State health department or CDC-supported testing, serum and/or CSF IgM/neutralization testing, PCR when appropriate and early, CBC, platelets, CMP, CSF studies for meningitis/encephalitis, and hospital evaluation for neurologic disease. |
| Alpha-gal syndrome and tick-associated allergy | Delayed reactions after mammalian meat, gelatin, dairy, medications, or biologics belong in the tick-associated differential even when infection tests are negative. | Alpha-gal IgE, total IgE, allergist evaluation, hidden-exposure review, epinephrine planning for anaphylaxis risk, and medication/gelatin review before procedures or new prescriptions. |
| Mycoplasma and chronic overlap | Kinderlehrer and Horowitz-style complex chronic Lyme care may include Mycoplasma when respiratory history, joint pain, neuropathy, fatigue, or autoimmune-like symptoms overlap with tick-borne illness. | Mycoplasma pneumoniae IgG/IgM and PCR, broader Mycoplasma PCR through MDL or other specialty labs when appropriate, respiratory panels for acute illness, and immune/inflammatory labs when chronic overlap is suspected. |
* Many non-Lyme tick-borne diseases are time-sensitive. In severe acute illness, clinicians should not wait for specialty testing before evaluating urgent treatment and public-health testing pathways. *
Sources used for this atlas
- CDC: About Ticks and Tickborne Disease
- Fallon and Sotsky, Conquering Lyme Disease
- Kinderlehrer, Recovery From Lyme Disease
- Horowitz, How Can I Get Better?
- Buhner, Healing Lyme Disease Coinfections
- McFadzean and Burrascano, The Beginner's Guide to Lyme Disease
Care priorities
When the diagnosis is unclear, geography, timing, labs, urgency, and overlap guide the next step.
Clear documentation helps clinicians decide which infections are plausible, which tests are time-sensitive, and which symptoms need urgent care.
- Geography: Identify pathogens known in the region where the patient was bitten, traveled, hiked, camped, gardened, hunted, or worked outdoors.
- Timing: Record when fever, rash, neurologic symptoms, joint pain, breathing symptoms, or cognitive changes began after exposure.
- Labs: Use CBC, platelets, liver enzymes, sodium, kidney markers, inflammatory markers, smear, PCR, or paired antibody testing when the clinical pattern supports it.
- Urgency: Treat severe fever, confusion, stiff neck, fainting, chest pain, shortness of breath, pregnancy, immune suppression, no spleen, or rapidly worsening illness as urgent.
- Multiple infections: Evaluate Lyme, Bartonella, Babesia, anaplasma/ehrlichia, rickettsial illness, relapsing fever Borrelia, mold/CIRS, and viral illness when symptoms overlap.
- Prevention: Match tick prevention, clothing treatment, repellents, tick checks, landscape changes, and pet protection to the household and local tick ecology.
Red flags
Do not wait on severe or rapidly worsening symptoms.
High fever, confusion, stiff neck, fainting, chest pain, shortness of breath, severe headache, pregnancy, immune suppression, or rapidly worsening illness should be evaluated urgently.