From the Guidelines
Ehrlichiosis should be treated promptly with doxycycline 100mg twice daily for 7-14 days, even before laboratory confirmation in suspected cases, as this medication is effective against all ehrlichial species and is recommended for patients of all ages, including children. The diagnosis of ehrlichiosis is typically made through a combination of clinical presentation, laboratory findings, and diagnostic tests such as PCR or antibody tests 1. Symptoms of ehrlichiosis typically appear 1-2 weeks after a tick bite and include fever, headache, muscle aches, fatigue, and sometimes a rash. Laboratory findings often show low white blood cell count, low platelet count, and elevated liver enzymes.
Some key points to consider in the management of ehrlichiosis include:
- The use of doxycycline as the first-line treatment, as it is effective against all ehrlichial species 1
- The importance of prompt treatment, even before laboratory confirmation, to prevent severe complications and improve outcomes 1
- The need for careful consideration of alternative treatments, such as rifampin, in patients who are pregnant or have a documented allergy to tetracycline-class drugs 1
- The potential for severe complications, particularly in immunocompromised individuals, the elderly, and young children, and the need for close monitoring and supportive care in these patients 1
Prevention of ehrlichiosis involves using tick repellents containing DEET, wearing protective clothing in wooded areas, checking for ticks after outdoor activities, and promptly removing attached ticks. Ehrlichiosis can become severe if left untreated, potentially causing organ failure, respiratory problems, and neurological complications, particularly in immunocompromised individuals, the elderly, and young children 1. The bacteria infect and multiply within white blood cells, causing systemic inflammation that leads to the characteristic symptoms and potential complications.
It is also important to note that some antibacterial agents, such as sulfonamides, can worsen the disease and should be avoided 1. In addition, the use of fluoroquinolones has been associated with delayed subsidence of fever, increased disease severity, and longer hospital stay, and is not recommended for treatment of ehrlichiosis 1.
From the Research
Overview of Ehrlichiosis
- Ehrlichiosis is a serious disease that can be fatal if not treated appropriately 2
- It is generally thought that if patients with ehrlichiosis are treated promptly, life-threatening illness can be avoided, but severe cases can still occur despite early treatment 3
- The disease is caused by at least 5 separate obligate intracellular bacteria in 3 genera in the family Anaplasmataceae 4
Clinical Presentation and Diagnosis
- Human ehrlichioses generally present as undifferentiated fever, but thrombocytopenia, leukopenia, and increased serum transaminase activities are important laboratory features 4
- The diseases can be diagnosed using laboratory methods such as blood smear examination, polymerase chain reaction, culture, and serologic tests 4
- A high suspicion for ehrlichiosis and a low threshold for instituting empiric antibiotic therapy with doxycycline is recommended for clinicians living in an area where Ehrlichia is endemic 2
Treatment and Outcomes
- Currently recommended treatment regimens for human monocytic ehrlichiosis (HME) include doxycycline or tetracycline, but rifampin has also shown to be effective in some cases 5
- Delay in initiation of doxycycline therapy is a significant factor associated with severe ehrlichiosis 6
- Early treatment with doxycycline can improve outcomes and reduce the risk of intensive care unit admission, mechanical ventilation, and longer hospital stay 2
- Documentation of tick exposure is independently associated with a decreased risk for ICU admission 6