Ehrlichiosis Anaplasmosis

Template:Helvetica Spotted Fever Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Ilan Dock, B.S.

Overview

Ehrlichiosis diseases are caused by the Ehrlichial species of bacteria, E. chaffeensis, E.muris, and E. ewingii. The Ehrlichial bacteria that cause human infection are most often transmitted by the lone star tick (amblyomma americanum.) The disease begins with an incubation period of 1-2 weeks post inoculation, followed by typical disease symptoms (fever, headache, fatigue, and muscle aches). Diagnosis is based on clinical presentation of symptoms, especially if a recent tick bite is noted. Confirmation of the disease may be done with laboratory testing. Doxycycline is often the first line treatment for individuals of all ages.

Risk Factors

• Tick bites are the most potent risk factor when contracting Ehrlichiosis.
• Tick bites are more likely to occur during seasons of heightened tick activity, including the spring and summer months. However tick bites may occur year round.

Diagnosis

Symptoms

The following is a list of common symptoms associated with Ehrlichiosis, however individuals may present symptoms differently. Therefore each patient should be individually evaluated for a potential combination of Ehrlichiosis symptoms.

• Fever
• Malaise (generally feeling sickly)
• Chills
• Muscle Pain
• Nausea
• Headache
• Vomiting
• Diarrhea
• Confusion
• Conjuctival injection (pink eye)
• Rash

Rash

The Ehrlichiosis rash may occur with a few different types of features:

• The rash may appear maculopapular or petechial.
• A rash that may be associated with Ehrlichiosis is not usually itchy.
• Does not usually appear of the face, though it may appear on palms and soles.
• Erythroderma, a sunburn like rash, may appear within a few days of symptoms onset.
• Ehrlichiosis rashes may resemble those of Rocky mountain spotted fever. Therefore laboratory tests may be required to differentiate Ehrlichiosis from other tick-borne diseases.

Treatment

Medical Therapy

• Treatment is most effective during the early course of the disease.
• If Ehrlichiosis is suspected a regimen of Doxycycline is administered for 7 to 14 days.

Doxycycline:

• Adult- 100mg every 12 hours

Children (under 100lbs) 2.2 mg/kg of body weight, twice a day.

Prevention

• Avoiding tick bites and endemic regions are the best methods in avoiding Ehlichiosis.