When people think of tick-borne illnesses, Lyme disease is usually the first, and sometimes only, one that comes to mind. Unfortunately, there are a slew of other infections that can be spread via a tick bite.
One of those is Rocky Mountain Spotted Fever, or RMSF. Although it’s different from Lyme disease, RMSF comes with its own risks and complications. It’s important to know the signs and symptoms, as well as the difference between these two infections, especially if you’re exposed to ticks more frequently.
Let’s take a look at Rocky Mountain Spotted Fever vs. Lyme disease so that you can be proactive in taking care of your health.
Bacterial Differences
Although they’re both spread through tick bites, Rocky Mountain Spotted Fever and Lyme disease are different infections. The biggest difference is the kind of bacteria that causes the infections.
Lyme disease is caused by species from the bacteria group borrelia burgdorferi, while RMSF is caused by a bacteria known as rickettsia. Outside of causing different symptoms, you can determine the type of infection through laboratory testing.
Symptoms of Rocky Mountain Spotted Fever vs. Lyme Disease
Even though they’re both transmitted through ticks, these two infections can cause distinct symptoms.
The main symptoms of Lyme disease include:
- Headache
- Fever
- Fatigue
- Erythema migrans rash (though many, if not most, patients don’t notice or experience a rash)
- Joint aches
- Swollen lymph nodes
The main Rocky Mountain Spotted Fever symptoms include:
- Nausea and vomiting
- Lack of appetite
- Rash
- Headache
- Fever
- Stomach pain
- Muscle pain
Although they have different symptoms, both RMSF and Lyme disease can be difficult to diagnose because oftentimes the symptoms aren’t specific to these illnesses. This is especially true if someone didn’t know that they were bit by a tick in the first place.
Risks and Complications
When left untreated, both infections can lead to serious complications that can greatly impact someone’s quality of life.
Some long-term complications from Lyme disease include:
- Nerve pain
- Irregular heartbeat or heart palpitations (Lyme carditis)
- Facial palsy
- Arthritis with joint swelling and pain, especially in the knees and other large joints
- Dizziness or shortness of breath
- Pain in tendons, muscles, bones, and joints
- Severe headaches and neck stiffness
Although symptoms can be debilitating for some people, Lyme disease is only rarely fatal. Mortality rates amongst patients with it were not higher than those in the general population.
Potential long-term complications from Rocky Mountain Spotted Fever infection include:
- Damage to blood vessels in arms, legs, fingers, or toes that can lead to amputation
- Paralysis
- Mental disability
- Hearing loss
The mortality rate of RMSF is higher than that of Lyme disease. For some patients, the fatality rate of RMSF is as high as 30%. In general, even with treatment, hospitalization rates are about 72%, with a 4% mortality rate. Chances of a full recovery are highest in patients who are treated with doxycycline within the first 5 days of infection.
RMSF vs. Lyme disease and the ticks that spread them
Rocky Mountain Spotted Fever and Lyme disease are also transmitted by different kinds of ticks. Although different ticks are common in different regions, the prevalence of ticks is growing as a result of climate change and other factors.
RMSF is most often transmitted by the American dog tick, which can be found in the Central, Eastern, and Western areas of the United States. It can also be spread by the brown dog tick, which is found in the Southwestern U.S. near the Mexican border, as well as the Rocky Mountain wood tick in the Rocky Mountain states. Tennessee, Missouri, Oklahoma, Arkansas, and North Carolina account for over 60% of RMSF cases, but cases have been found throughout most of the U.S.
Lyme disease, on the other hand, is transmitted by black-legged ticks, also known as deer ticks, which are found in the upper midwestern and northeastern U.S. Along the Pacific coast, Lyme disease is carried by the western black-legged tick. States with the highest rates of Lyme disease include Connecticut, Delaware, Washington D.C., Maine, Maryland, New Jersey, New Hampshire, New York, Pennsylvania, Vermont, Virginia, and Wisconsin, though it can occur in any state.
Protecting yourself from tick-borne infections
Now that you understand the biggest differences between Rocky Mountain Spotted Fever vs. Lyme disease, it’s important to take steps to prevent tick bites from happening in the first place.
This includes covering your arms and legs when in areas where ticks are prevalent, along with using an insect repellent containing DEET, picaridin, or lemon eucalyptus oil.
Sometimes tick bites are unavoidable. When they do happen, it’s important to remove the tick properly, track any symptoms, and seek out testing as soon as possible through comprehensive services like the ones offered at IGeneX. If you’re able to, it’s helpful to get the tick tested as well to better determine what bacteria was present so that your provider can treat you accordingly.