id.lyme-disease.core.v1PRODUCTION

id.lyme-disease.core.v1

Lyme disease (early localized → late)

infectious_diseaseacutesubacutechronicadultpediatric

Hard-required inputs

0 / 1

Care setting:

Encounter flow

12/12 authored

Canonical 12-phase frame with authored status for this dossier.

Current phase

Frame

Detailed

Lyme disease across stages: early localized (EM), early disseminated (neuro, cardiac, multiple EM), late (arthritis, encephalopathy). Post-treatment Lyme syndrome routed separately (IDSA 2024)

Inputs

Actions

Advance rule

Set

Advance when

scope confirmed

Patient inputs (10)

tick_exposure_endemic_area*history • CONTEXT

not present

Pre-test probability anchor; without exposure / endemicity, alternative diagnoses dominate (IDSA 2024)

neuro_symptomssymptom • BRANCHING_WORKUP

Cranial neuropathy / meningitis / radiculopathy → IV ceftriaxone vs PO doxycycline (severity-dependent) (IDSA 2024)

csf_studies_if_neurolab • BRANCHING_WORKUP

CSF lymphocytic pleocytosis + intrathecal antibody index for neuroborreliosis (IDSA 2024)

synovial_fluid_pcrlab • BRANCHING_WORKUP

Borrelia PCR on synovial fluid in late Lyme arthritis (IDSA 2024)

tick_attachment_durationhistory • CONTEXT

not present

≥36 hours Ixodes scapularis attachment supports post-exposure prophylaxis (IDSA 2024)

em_lesion_size_and_patternsymptom • ENTRY

EM ≥5 cm with central clearing is clinical diagnosis — no serology needed (IDSA 2024)

lyme_serology_2_tierlab • INITIAL_WORKUP

CDC modified 2-tier (ELISA → ELISA OR ELISA → IB) — supports disseminated disease; not needed for EM

cardiac_symptomssymptom • RED_FLAGS

AV block / myopericarditis → admission + IV ceftriaxone if symptomatic / high-grade (IDSA 2024)

pregnancy_statusdemographic • TREATMENT

Doxycycline duration-of-pregnancy considerations (recent literature supports short-course safety) (IDSA 2024)

weightdemographic • TREATMENT

Pediatric weight-based dosing of doxycycline (≥45 kg adult dose) and amoxicillin (IDSA 2024)

* = hard-required. Engine cannot meaningfully run until these are filled.

Severity triggers (10)

10 need judgement

informationallife_threateninglyme_carditis_with_av_block
Lyme carditis with high-grade AV block — PR > 0.3 s OR Mobitz II OR complete heart block OR symptomatic high-grade AV (syncope, severe palpitations) in patient with tick exposure (IDSA / AAN / ACR 2020 — life-threatening if symptomatic)
Trigger could not be auto-evaluated — needs clinician judgement.
informationalseverehigh_grade_avb_carditis (IDSA 2024)
Mobitz II, complete AV block, or PR >300 ms with symptoms in patient with Lyme exposure (IDSA 2024)
Trigger could not be auto-evaluated — needs clinician judgement.
informationalseveresevere_neuroborreliosis (IDSA 2024)
Meningoencephalitis with altered mental status, severe meningitis, or progressive radiculopathy (IDSA 2024)
Trigger could not be auto-evaluated — needs clinician judgement.
informationalseverelyme_meningitis_or_encephalitis
Lyme meningitis with severe headache + meningismus OR encephalitis with altered mental status OR progressive radiculopathy / radiculoneuritis with severe pain OR multiple cranial neuropathies (IDSA / AAN / ACR 2020)
Trigger could not be auto-evaluated — needs clinician judgement.
informationalseverecoinfection_suspected_with_severe_features
Lyme exposure + severe atypical features suggesting tick-borne coinfection — hemolysis or hemoglobinuria (babesiosis Babesia microti) OR profound cytopenias + transaminitis + severe headache (anaplasmosis Anaplasma phagocytophilum) OR meningoencephalitis-with-rapid-deterioration in Northeast US summer (Powassan virus) OR relapsing fever pattern (hard tick relapsing fever Borrelia miyamotoi) (IDSA / AAN / ACR 2020)
Trigger could not be auto-evaluated — needs clinician judgement.
informationalmoderateantibiotic_refractory_lyme_arthritis
Persistent inflammatory knee arthritis after 2 oral courses (28 d each) of doxycycline (IDSA 2024)
Trigger could not be auto-evaluated — needs clinician judgement.
informationalmoderateco_infection_anaplasma_or_babesia
Tick exposure + atypical features (severe headache + cytopenias + transaminitis = anaplasma; hemolysis + parasitemia = babesia) (IDSA 2024)
Trigger could not be auto-evaluated — needs clinician judgement.
informationalmoderatepregnancy_lyme
Suspected or confirmed Lyme in pregnant patient (IDSA 2024)
Trigger could not be auto-evaluated — needs clinician judgement.
informationalmildpost_treatment_lyme_disease_syndrome
Subjective fatigue / arthralgia / cognitive symptoms persisting after appropriate treatment (IDSA 2024)
Trigger could not be auto-evaluated — needs clinician judgement.
informationalmildsingle_dose_doxycycline_prophylaxis_eligible
Post-exposure single-dose doxycycline prophylaxis eligibility — ALL of: within 72 h of tick removal + Ixodes scapularis (or I. pacificus on West Coast) identified + attachment duration ≥ 36 h (engorgement-estimated) + tick removal in Lyme-endemic area (≥ 20% local Ixodes carriage) (IDSA / AAN / ACR 2020 conditional recommendation)
Trigger could not be auto-evaluated — needs clinician judgement.

Workflow calculators

This dossier does not reference any calculators.

Recommended regimen

Lyme — stage-based antibiotic regimen (IDSA/AAN/ACR 2020)

axis: lyme_stage_based_treatmentstep 1 - Early localised — erythema migrans, no neuro/cardiac features (IDSA 2024)

Selected step "Early localised — erythema migrans, no neuro/cardiac features (IDSA 2024)" — EM ≥5 cm in endemic area, ± mild flu-like symptoms, no facial palsy, no carditis, no arthritis

doxycycline
first line
tetracycline
100 mg PO BID • PO • BID × 10-14 d
triggers: early_localised, no_pregnancy, age_>=8_years
IDSA 2020 — preferred; covers Anaplasma co-infection; 10 d non-inferior to 14 d
rxcui 3640
amoxicillin
first line
aminopenicillin
500 mg PO TID • PO • TID × 14 d
triggers: pregnancy, lactation, children_under_8
IDSA 2020 alternative; preferred in pregnancy
rxcui 723
cefuroxime_axetil
second line
2nd_gen_cephalosporin
500 mg PO BID • PO • BID × 14 d
triggers: doxycycline_intolerant, amoxicillin_allergy_partial
IDSA 2020 alternative
rxcui 20493

outpatient playbook — drug actions (5)

1. doxycycline
100 mg PO BID (IDSA 2024) • PO • BID × 10-14 d (IDSA 2024)
trigger: Early localised Lyme (EM) (IDSA 2024)
IDSA 2020 first-line; covers Anaplasma
2. amoxicillin alternative
500 mg PO TID • PO • TID × 14 d
trigger: Pregnancy or children <8 (IDSA 2024)
IDSA 2020 alternative
3. doxycycline single dose (post-exposure prophylaxis)
200 mg PO × 1 • PO • single
trigger: Ixodes attached ≥36 h in endemic area within 72 h of removal (IDSA 2024)
IDSA 2020 — meta-analysis NNT 50
4. doxycycline 14-21 d
100 mg PO BID • PO • BID × 14-21 d
trigger: Early disseminated mild (e.g., isolated facial palsy) (IDSA 2024)
IDSA 2020 PO non-inferior to IV for most early neuro Lyme
5. doxycycline 28 d
100 mg PO BID • PO • BID × 28 d
trigger: Late Lyme arthritis (initial course) (IDSA 2024)
IDSA 2020 — 28 d PO is first attempt

Auto-drafted A&P note

outpatient

Subjective

- Possible entry pathways: Erythema migrans (>=5 cm bullseye lesion in endemic area) (IDSA 2024); Recent tick bite in Ixodes-endemic region (IDSA 2024); New facial palsy or aseptic meningitis with exposure (IDSA 2024).

Objective

- No vitals, labs, or imaging entered for this encounter.

Assessment

**Lyme disease (early localized → late)** (id.lyme-disease.core.v1).
Phenotype framing: STARI (south-east US), Lyme-mimicking dermatophyte / cellulitis / spider bite, Bell palsy idiopathic, viral meningitis, septic arthritis, RA, sarcoid, anaplasma / babesia co-infection (IDSA 2024)
Scope: Lyme disease across stages: early localized (EM), early disseminated (neuro, cardiac, multiple EM), late (arthritis, encephalopathy). Post-treatment Lyme syndrome routed separately (IDSA 2024)

No severity triggers fired against current inputs.

Plan

Regimen axis: **Lyme — stage-based antibiotic regimen (IDSA/AAN/ACR 2020)** — step "Early localised — erythema migrans, no neuro/cardiac features (IDSA 2024)".
1. doxycycline 100 mg PO BID PO BID × 10-14 d (tetracycline, first line) — IDSA 2020 — preferred; covers Anaplasma co-infection; 10 d non-inferior to 14 d
2. amoxicillin 500 mg PO TID PO TID × 14 d (aminopenicillin, first line) — IDSA 2020 alternative; preferred in pregnancy
3. cefuroxime_axetil 500 mg PO BID PO BID × 14 d (2nd_gen_cephalosporin, second line) — IDSA 2020 alternative

Setting playbook (outpatient) — Diagnose and treat early localised / mild disseminated Lyme; counsel on tick prevention (IDSA 2024)
4. doxycycline 100 mg PO BID (IDSA 2024) PO BID × 10-14 d (IDSA 2024) — Early localised Lyme (EM) (IDSA 2024) (IDSA 2020 first-line; covers Anaplasma)
5. amoxicillin alternative 500 mg PO TID PO TID × 14 d — Pregnancy or children <8 (IDSA 2024) (IDSA 2020 alternative)
6. doxycycline single dose (post-exposure prophylaxis) 200 mg PO × 1 PO single — Ixodes attached ≥36 h in endemic area within 72 h of removal (IDSA 2024) (IDSA 2020 — meta-analysis NNT 50)
7. doxycycline 14-21 d 100 mg PO BID PO BID × 14-21 d — Early disseminated mild (e.g., isolated facial palsy) (IDSA 2024) (IDSA 2020 PO non-inferior to IV for most early neuro Lyme)
8. doxycycline 28 d 100 mg PO BID PO BID × 28 d — Late Lyme arthritis (initial course) (IDSA 2024) (IDSA 2020 — 28 d PO is first attempt)

Non-pharmacologic actions:
- Tick prevention counselling — DEET 20-30%, permethrin-treated clothing, tick checks within 2 h, prompt removal with fine-tipped tweezers (IDSA / AAN / ACR 2020; CDC)
- No need for routine serology if classic EM in endemic area (IDSA / AAN / ACR 2020 — clinical-diagnostic, EM pathognomonic)
- Refer to ID/rheum if antibiotic-refractory arthritis after 2× 28-d PO courses (IDSA / AAN / ACR 2020 — DMARD / synovectomy candidacy)
- PTLDS counseling — persistent fatigue / arthralgia / cognitive symptoms after adequate treatment occurs in ~10% of patients; subjective and time-limited in most; no repeat antibiotics indicated (IDSA / AAN / ACR 2020 strong against; Klempner NEJM 2001 PMID 11450676)
- Preventive counseling for next tick exposure — chemoprophylaxis eligibility (single-dose doxycycline 200 mg if Ixodes ≥ 36 h attached + endemic + within 72 h) discussed before next outdoor season (IDSA / AAN / ACR 2020)
- VLA15 (Valneva/Pfizer) Lyme vaccine — Phase 3 ongoing as of 2026; not yet a clinical recommendation; surveillance only

AVOID / contraindication checks:
- Doxycycline pregnancy historical block now conditional short course (IDSA 2024)
- Doxycycline children under 8 block except tickborne rickettsial (IDSA 2024)
- Amoxicillin penicillin allergy block (IDSA 2024)
- Ceftriaxone severe PCN allergy skin test (IDSA 2024)

Monitoring

Regimen monitoring:
- symptom resolution by end of course (IDSA 2024)
- EM resolves within 1-2 weeks (IDSA 2024)
- arthritis may take months to resolve post treatment (IDSA 2024)
- ECG monitoring for carditis (IDSA 2024)
- no routine test of cure serology (antibodies persist) (IDSA 2024)

Setting (outpatient) monitoring:
- Symptom resolution — EM 1-2 weeks; constitutional symptoms a few weeks; arthritis may take months even after cure (IDSA / AAN / ACR 2020)
- PTLDS surveillance at 1 mo, 3 mo, 6 mo — flag persistent subjective symptoms for functional rehab + multidisciplinary symptom management (IDSA / AAN / ACR 2020)
- No test of cure; serology stays positive after cure — do NOT use 2-tier or PCR for failure-of-cure (IDSA / AAN / ACR 2020)
- ECG if any cardiac symptoms during or after treatment — PR interval surveillance (IDSA / AAN / ACR 2020)

Follow-up plan: Counsel about post-treatment Lyme symptoms (subjective fatigue / arthralgia common — antibiotic re-treatment NOT recommended; supportive care + functional rehab); tick prevention education (IDSA 2024)
- Close-out criterion: education + tick prevention plan documented

Monitoring phase: Symptom resolution by end of course (EM resolves within 1-2 weeks); arthritis may take months even after cure (IDSA 2024)

Disposition

Current setting: outpatient — Diagnose and treat early localised / mild disseminated Lyme; counsel on tick prevention (IDSA 2024)

Disposition criteria:
- Continue PO at home for early-localised + mild-disseminated; admit if Lyme carditis with high-grade AVB OR severe neuroborreliosis OR refractory arthritis requiring IV ceftriaxone (IDSA / AAN / ACR 2020)
- Outpatient follow-up at 1-2 wk to confirm EM resolution; 1-3-6 mo for PTLDS surveillance; annual for those with recurrent tick exposure for chemoprophylaxis counseling (IDSA / AAN / ACR 2020)

Escalation triggers (move to higher acuity):
- New cardiac symptoms — palpitations, syncope, PR ≥ 0.3 s or symptomatic AV block → ED + admit + cardiology + IV ceftriaxone or PO doxy + temporary pacing if symptomatic (IDSA / AAN / ACR 2020)
- Severe headache / meningismus / altered mental status → ED + LP + IV ceftriaxone for severe neuroborreliosis (IDSA / AAN / ACR 2020)
- Refractory arthritis after 2× 28-d courses → ID + rheumatology (IDSA / AAN / ACR 2020 — DMARD / synovectomy candidacy)
- Persistent / progressive PTLDS symptoms beyond 6 mo despite functional rehab → multidisciplinary symptom-management (chronic pain, behavioral health) — NOT chronic antibiotics (IDSA / AAN / ACR 2020 strong against)

Earlier-Return Triggers

Return-precaution thresholds (watch for):
- [LIFE_THREATENING] Lyme carditis with high-grade AV block — PR > 0.3 s OR Mobitz II OR complete heart block OR symptomatic high-grade AV (syncope, severe palpitations) in patient with tick exposure (IDSA / AAN / ACR 2020 — life-threatening if symptomatic)
- [SEVERE] Mobitz II, complete AV block, or PR >300 ms with symptoms in patient with Lyme exposure (IDSA 2024)
- [SEVERE] Meningoencephalitis with altered mental status, severe meningitis, or progressive radiculopathy (IDSA 2024)

Citations

- IDSA / AAN / ACR 2020 Clinical Practice Guidelines for Lyme Disease (Lantos et al CID 2021) + CDC Modified 2-Tier Serology (MMWR 2019 Mead) + NICE NG95 (2018, updated 2024) + IDSA single-dose post-exposure doxycycline (Nadelman NEJM 2001) + Klempner PTLDS no-antibiotic NEJM 2001 [PMID:33417672](https://pubmed.ncbi.nlm.nih.gov/33417672/)
- Cited evidence (PMID 11450676) [PMID:11450676](https://pubmed.ncbi.nlm.nih.gov/11450676/)
- Cited evidence (PMID 11450675) [PMID:11450675](https://pubmed.ncbi.nlm.nih.gov/11450675/)

Last reconciled with current guidelines: 2026-05-22.

References

IDSA / AAN / ACR 2020 Clinical Practice Guidelines for Lyme Disease (Lantos et al CID 2021) + CDC Modified 2-Tier Serology (MMWR 2019 Mead) + NICE NG95 (2018, updated 2024) + IDSA single-dose post-exposure doxycycline (Nadelman NEJM 2001) + Klempner PTLDS no-antibiotic NEJM 2001 — PMID:33417672
Cited evidence (PMID 11450676) — PMID:11450676
Cited evidence (PMID 11450675) — PMID:11450675