Ticked Off About Rocky Mountain Spotted Fever

By now many of us have absorbed the most important messages about ticks and Lyme disease. We dutifully apply permethrin to our boots, avoid unneeded walks through tall grass, and do tick checks right after coming indoors. We know ticks are active more in warm weather and that nymphs are the most likely to transmit disease. And hopefully, most of us know that if you remove an attached tick quickly (within 24 hours) you can greatly reduce your chances of getting Lyme.

An identification card showing blacklegged, lone star, and dog ticks as larva, nymph, and adult
Identification of blacklegged, lone star, and dog ticks for larva, nymph, and adult stages.

Centers for Disease Control and Prevention

Yet even with all that good knowledge about avoiding Lyme, it might come as a surprise to learn that in December last year an National Capital Region (NCR) park visitor fell ill quickly with a rash and encephalitis ascribed to a tick borne disease called Rocky Mountain Spotted Fever. Rocky Mountain Spotted Fever (RMSF) is not a new condition, but it is in a category of illnesses (called Spotted Fever Rickettsioses) that have increased during the last decade. It can be a severe or even fatal illness if not treated in the first few days of symptoms. Typical symptoms include: fever, headache, abdominal pain, vomiting, and muscle pain. A rash may also develop, but is often absent in the first few days, and in some patients, never develops. Caught early though, like many tick borne diseases, it can be treated with antibiotics.

Besides the surprise of the time of year this occurred, it’s also interesting to note that RMSF is carried not by blacklegged (aka deer) ticks, but instead by dog ticks. Yes, dog ticks. The same gross, yet seemingly innocent type of tick that winds up legs in the air like a small dark grape on your kitchen floor after falling off the family dog. Who knew dog ticks even carried anything that humans needed to worry about?!

Now, rest assured, the park visitor who came down with RMSF was promptly hospitalized and made a full recovery. However, cases like this reaffirm the importance of vigilantly avoiding ticks of all kinds. Most tick borne diseases can be treated with antibiotics. Yet it still pays to prevent tick encounters and tick bites whenever possible. For the latest information on preventing tick bites and on tick-borne disease symptoms and treatments, visit the Centers for Disease Control and Prevention website: https://www.cdc.gov/ticks/

Ticks and Disease-Causing Pathogens in NCR



Lone Star Tick (Amblyomma americanum)

Dog Tick

(Dermacentor variabilis)

Black-legged (deer) Tick

(Ixodes scapularis)

Gulf Coast Tick

(Amblyomma maculatum)

Babesiosis Babesiosis microti Vector
Rocky Mountain Spotted Fever Rickettsia rickettsia Vector
Powassan Virus an RNA virus Vector
Ehrlichiosis Ehrlichiosis caffeensis, or E. ewingii Vector
Anaplasmosis Anaplasmosis phagocytophilum Vector Vector
Tularemia F. tularensis Vector
Lyme Borrelia burgdorferi Vector
Borrelia miyamotoi disease Borrelia miyamotoi Vector
STARI (southern tick-associated rash illness) Cause unknown Vector
Rickettisa parkeri rickettsiosis Rickettsia parkeri Vector

Last updated: March 5, 2018