A patient with recent travel to the northwoods of Wisconsin presented with high grade fever, rash, and generalized lethargy for 7 dats in the setting of increasing LFTs.
The patient was originally thought to have Lyme Disease but was not treated after an EIA test came back negative. However, the low sensitivity of this test early in a course of symptoms justifies treatment based off of clinical suspicion and physical exam alone.
Lyme Disease:
- Phases:
1. Early localized
Onset: ≤ 4 wks
Findings: EM at site of tick attachment, fever, lymphadenopathy, myalgia
Rx: Doxycycline 100 mg PO BID x 10-21d
2. Early disseminated
Onset: 2 wks – 6 mo
Findings: multiple sites of EM, flu-like syndrome, heart block, myocarditis, facial nerve palsy, meningitis, radiculitis
Rx: depends on complication*
3. Late disseminated
Onset: ≥ 6 mo
Findings: Recurrent large joint arthritis, neurologic sx (peripheral neuropathy, encephalopathy), dermatologic sx (acrodermatitis chronica atrophicans)
Rx: depends on complication*
* Neuro cx = IV Ceftriaxone x28d,
AV Block = IV Ceftriaxone x 28d
- Testing:
No confirmatory labs are needed if EM is present.
Two-tiered serologic testing if EM is not present, or is unclear
CSF testing for intrathecal antibody production and lymphocytic pleocytosis if concern for meningitis
**See two tier testing image above**
Post-Lyme Disease Syndrome:
10% pts post-EM rx
Characterized by persisting fatigue, arthralgia, myalgia, impiared memory/cognition that can last for years.
MUST exclude Babesiosis/other tic-borne infection
Co-Infections
- Babesiosis: Intraerythrocytic protozoan
Tic: I. scapularis
Fatal disease in 10%
RF: >50 yo, immunocompromised, asplenia
Sx:Fever, fatigue, headache, myalgias, cough
PE: jaundice, hepatomegaly, splenomegaly
Labs: hemolytic anemia, elevated LFTs, AKI
Histology: Blood smear shows intraerythrocytic ring forms or tetrads resembling Maltese crosses. PCR or serology if smear is negative and suspicion is high.
Tx: mild to moderate: atovaquone + azithromycin
Severe: (requiring ICU or exchange transfusion (>10% parasitemia)): clindamycin + quinine
Two others that similarly present:
- Anaplasmosis: = Anaplasma phagocytophilium
Tic: I. scapularis
- Erlichiosis: = Erlichia chaffeensis
Tic: Lone Star Tic
- Common Sxs: febrile illness, RASH UNLIKELY
Labs: leukopenia, thrombocytopenia, AKI, transaminitis
Histology: basophilic inclusion bodies in cytoplasm of leukocytes.
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