Ehrlichiosis masquerading as thrombotic thrombocytopenic purpura.

Chen D, et al. BMJ Case Rep. 2018.


Ehrlichiosis is a rare tickborne illness that can manifest from an asymptomatic, self-limiting disease to a severe presentation with encephalopathy and renal failure. Ehrlichiosis is diagnosed largely based on patient history with confirmatory tests including peripheral blood smear, serology and PCR. Empiric treatment is warranted in patients with suspected tick bites as a delay in treatment can result in multiorgan failure. We discuss a case of ehrlichiosis that presented with the classic pentad of thrombotic thrombocytopenic purpura (TTP). A history of a tick bite was elicited and intravenous doxycycline 100 mg two times a day was initiated. Tick panel results revealed a positive Ehrlichia chaffeensis IgG and IgM titres, consistent with human monocytic ehrlichiosis. Autoimmune workup and antibodies to Borrelia burgdorferi were negative, and ADAMTS13 activity assay results were inconsistent with TTP. The patient completed 14 days of intravenous doxycycline and had an uneventful recovery.


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Thrombotic Thrombocytopenic Purpura (TTP) causes tiny blood clots throughout your body.  This can block blood vessels and impede blood flow.  The clots can use up too many platelets which in turn can inhibit clot formation when you need it.
Symptoms include:
  • Purplish bruises (purpura) from no obvious cause
  • tiny red or purple spots that look like a rash
  • skin may turn yellowish (jaundice)
  • skin may look pale
  • fever
  • fatigue
  • confusion
  • weakness
  • headache
  • In very serious cases, a stroke, major internal bleeding, or a coma can occur
In May 2017, an article in the CDC “Emerging Infectious Diseases” Journal, warns that ehrlichiosis infections are being “grossly underreported” in the U.S. with as many as 97-99% of infections going unrecognized. They are projecting that the actual number of annual cases could go as high as 1/2 the number of Lyme disease cases—which would mean we may already have over 150,000 cases of ehrlichiosis annually. (3)
Rickettsiae and Ehrlichia belong to a broad group of bacteria that can be spread by a tick bite. These infections can be transmitted alone or at the same time as Lyme disease and are commonly known as co-infections.


The Ehrlichia (E) group includes: (5, 6, 7, 8,)

  • chaffeensis: the cause of human monocytic ehrlichiosis (HME)
  • ewingii
  • muris-like (EML)

While some cases of ehrlichiosis are mild, the disease can be severe or fatal if not treated correctly, even in previously healthy people. Severe symptoms of ehrlichiosis may include difficulty breathing, respiratory failure, bleeding disorders, kidney or heart failure.

Because Ehrlichia infect white blood cells (the cells that fight infection), and mitochondria (the powerhouse of the human cell) the consequences of untreated infection may have long-lasting effects.(9) I often wonder if undiagnosed Ehrlichiosis isn’t responsible for some portion of the millions of people with the mysterious illness known as “Myalgic Encephalomyelitis” or “Chronic Fatigue Syndrome”.

Other symptoms of ehrlichiosis can include:

  • Fever/chills and headache (majority of cases)
  • Fatigue/malaise (over two-thirds of cases)
  • Muscle/joint pain (25% – 50%)
  • Nausea, vomiting and/or diarrhea (25% – 50%)
  • Cough (25% – 50%)
  • Confusion or brain fog (50% of children, less common in adults)
  • Lymphadenopathy (47% – 56% of children, less common in adults)
  • Red eyes (occasionally)
  • Rash (approximately 60% of children and 30% of adults)

Diagnosis And Treatment
Like other tick-borne diseases, diagnostic blood tests will frequently be false-negative during the first weeks of illness. And like other tick-borne diseases, treatment is most effective if started early. For this reason, healthcare providers must use their best clinical judgement and treat patients based upon early symptoms alone.

According to the CDC website: “The diagnosis of ehrlichiosis must be made based on clinical signs and symptoms, and can later be confirmed using specialized confirmatory laboratory tests. Treatment should never be delayed pending the receipt of laboratory test results, or be withheld on the basis of an initial negative laboratory result.”

The CDC goes on to say: “Doxycycline is the first line treatment for adults and children of all ages and should be initiated immediately whenever ehrlichiosis is suspected.” (10)

Patients who are treated early may recover quickly on outpatient medication, while those who experience a more severe illness may require intravenous antibiotics, prolonged hospitalization or intensive care.

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