It's my understanding that Erlichliosis is usually taken care of with doxy when we treat lyme...which is often one of the first antibiotics prescribed for Lyme.
So, for those of us that don't start out treating with doxy...it could remain untreated.
From Dr. B's guidelines:
EHRLICHIA (AND ANAPLASMA)
GENERAL INFORMATION
While it is true that this illness can have a fulminant presentation, and may even become fatal if not treated, milder forms do exist, as does chronic low-grade infection, especially when other tick-borne organisms are present. The potential transmission of Ehrlichia during tick bites is the main reason why doxycycline is now the first choice in treating tick bites and early Lyme, before serologies can become positive. When present alone or co-infecting with B. burgdorferi, persistent leuk
openia is an important clue. Thrombocyt
openia and elevated liver enzymes, common in acute infection, are less often seen in those who are chronically infected, but likewise should not be ignored. Headaches, myalgias, and ongoing fatigue suggest this illness, but are extremely difficult to separate from symptoms caused by Bb.
DIAGNOSTIC TESTING
Testing is problematic with Ehrlichia, similar to the situation with Babesiosis. More species are known to be present in ticks than can be tested for with clinically available serologies and PCRs. In addition, serologies and PCRs are of unknown sensitivity and specificity. Standard blood smears for direct visualization of organisms in leukocytes are of low yield. Enhanced smears using buffy coats significantly raise sensitivity and can detect a wider variety of species. Despite this, infection can be missed, so clinical diagnosis remains the primary diagnostic tool. Again, consider this diagnosis in a Lyme Borreliosis (LB) patient not responding well to Lyme therapy who has symptoms suggestive of Ehrlichia.
TREATMENT
Standard treatment consists of Doxycycline, 200 mg daily for two to four weeks. Higher doses, parenteral therapy, and longer treatment durations may be needed based on the duration and severity of illness, and whether immune defects or extreme age is present. However, there are reports of treatment failure even when higher doses and long duration treatment with doxycycline is given. In such cases, consideration may be given for adding rifampin, 600 mg daily, to the regimen.
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From Lyme and Tick-Borne Diseases Research Centre (Columbia University)
No treatment studies have been performed for ehrlichiosis, but empiric evidence indicates that tetracyclines are highly effective against both E. chaffeensis and E. ewingii. The most commonly employed regimen is oral doxycycline at a dose of 100 mg every 12 hours, for 5-14 days.
(Doxycycline is also recommended for pediatric patients.) In severe cases, intravenous therapy is used or antibiotic treatment is extended. Consensus exists that in all cases, treatment should be continued in all patients for at least 3-5 days after the fever subsides.
In cases where doxycycline is contraindicated, such as pregnancy or allergy, rifampin is usually the alternative choice. Little data exists to support the use of any other antibiotic, as cephalosporins, macrolides, beta lactams and aminoglycosides are all inactive against Ehrlichia organisms in vitro.
columbia-lyme.org/patients/tbd_ehrli-anapla.html