What are the symptoms of Ehrlichiosis?

Symptoms of Ehrlichiosis

The primary symptoms of ehrlichiosis include fever (96%), headache (72%), malaise (77%), myalgia (68%), and gastrointestinal manifestations such as nausea (57%), vomiting (47%), and diarrhea (25%). 1

Common Symptoms

• Fever: Nearly universal symptom (96% of cases)

• Constitutional symptoms:

  • Headache (72%)
  • Malaise/fatigue (77%)
  • Muscle aches/myalgia (68%)
  • Shaking chills

• Gastrointestinal manifestations:

  • Nausea (57%)
  • Vomiting (47%)
  • Diarrhea (25%)
  • Abdominal pain (more common in children)

• Respiratory symptoms:

  • Cough (28% of patients)
  • More common in adults than children

Less Common but Important Symptoms

• Rash: Present in approximately one-third of patients

  • More common in children than adults
  • Typically appears about 5 days after illness onset
  • Can be petechial, maculopapular, or diffuse erythema
  • Usually involves extremities and trunk, but can affect palms, soles, or face

• Neurologic manifestations: Present in approximately 20% of patients

  • Can include meningitis or meningoencephalitis

Laboratory Findings

Characteristic laboratory abnormalities include:

• Leukopenia (low white blood cell count)
• Thrombocytopenia (low platelet count)
• Elevated liver enzymes (hepatic transaminases)
• Anemia (occurs later in the illness, seen in 50% of patients)
• Mild to moderate hyponatremia

Variations by Ehrlichia Species

1. Ehrlichia chaffeensis (Human Monocytic Ehrlichiosis)

   • All symptoms described above
   • Case-fatality rate approximately 3%
   • Morulae may be observed in monocytes

2. Ehrlichia ewingii

   • Similar to E. chaffeensis but with fewer gastrointestinal symptoms
   • Rash is rare
   • No deaths reported
   • Morulae may be observed in granulocytes

3. Ehrlichia muris-like agent (EML)

   • Fever (87%), malaise (76%), headache (67%), myalgia (60%)
   • Rash reported in only 12% of cases
   • No fatal cases reported

Severe Manifestations

In severe cases, ehrlichiosis can lead to:

• Acute respiratory distress syndrome (ARDS)
• Toxic shock-like or septic shock-like syndromes
• Renal failure
• Hepatic failure
• Coagulopathies
• Hemorrhagic complications

Risk Factors for Severe Disease

• Age ≥60 years
• Immunosuppression (HIV, organ transplantation, immunosuppressive therapy)
• Young children (<10 years) have highest case-fatality rate
• Receipt of sulfonamide antibiotics may predispose to severe illness

Important Clinical Considerations

• Symptoms typically appear 5-14 days after tick bite (median 9 days for E. chaffeensis)
• Early recognition is critical as delayed diagnosis and treatment can lead to increased mortality
• The absence of rash does not rule out ehrlichiosis
• Laboratory abnormalities are important diagnostic clues when clinical presentation is nonspecific

Remember that ehrlichiosis can be confused with other tick-borne diseases like Rocky Mountain spotted fever or anaplasmosis, but the specific pattern of symptoms and laboratory findings can help differentiate between these conditions 1, 2.