Fibromyalgia vs. polymyalgia: Differences in symptoms, causes, and treatment

Fibromyalgia and polymyalgia rheumatica may sound the same and even share similar, overlapping symptoms, but they both have unique differences that set them apart. Polymyalgia is often misdiagnosed for fibromyalgia or can be overlooked in patients who have already been diagnosed with fibromyalgia, so recognizing these key differences can greatly aid in treatment and management.

Here is a quick overview of either condition. Fibromyalgia is a condition characterized by all-over pain, fatigue, memory problems, and sleep disturbances. Polymyalgia rheumatica is a condition in which the large arteries become inflamed. White blood cells attach onto the joints, so pain and stiffness occurs as a result. Fatigue and weight loss can also occur in polymyalgia.

In this article, we will further outline the differences and similarities between fibromyalgia and polymyalgia, so you can develop a better understanding of both conditions.

Difference between fibromyalgia and polymyalgia

There are some key differences between fibromyalgia and polymyalgia:

• Polymyalgia causes resting muscle pain whereas fibromyalgia is deep pressure pain.
• Polymyalgia commonly affects the elderly, while fibromyalgia is more common in those of middle age.
• Both conditions are associated with psychiatric conditions, in fibromyalgia there are abnormally higher mental functions.
• Polymyalgia responds to steroids, while fibromyalgia requires more targeted treatment.
• Polymyalgia involves inflammation, while fibromyalgia does not.
• Polymyalgia is believed to be an autoimmune disease, unlike fibromyalgia.
• Polymyalgia pain is located in specific areas whereas fibromyalgia is widespread.
• Polymyalgia typically appears quickly, unlike fibromyalgia.

Polymyalgia vs. fibromyalgia: U.S. prevalence

Roughly two to four percent of the U.S. population are affected by fibromyalgia. Estimates of U.S. prevalence were done based on the 1990 American College of Rheumatology (ACR) guidelines for the fibromyalgia diagnosis, accounting for roughly 10 million cases of fibromyalgia. But it has since been argued that these estimates are too low, and the guidelines fail to capture many patients who could be living with fibromyalgia unknowingly.

Some estimates of the economic impact of fibromyalgia amount to over $10,000 per patient annually. On average, a fibromyalgia patient will miss up to 17 days of work.

Prevalence of polymyalgia is 8.4/10,000 person-years, and a lifetime risk is 2.4 percent for women and 1.7 percent for men. Because polymyalgia can appear like many other conditions, prevalence may not be accurate as many patients may be misdiagnosed or undiagnosed.

Polymyalgia vs. fibromyalgia: Demography and age of onset

Fibromyalgia typically affects those of middle age and women. Polymyalgia, on the other hand, is more common among older adults and seniors, but also affects women more than men, too.

The ratio between women and men for polymyalgia is 2:1, while in fibromyalgia it is 4:1.

Comparing fibromyalgia and polymyalgia symptoms and causes

The key distinguishing symptom of fibromyalgia is tender points located on the body. Other signs and symptoms of fibromyalgia include chronic muscle pain, muscle spasms or tightness, moderate or severe fatigue, decreased energy, insomnia, waking up feeling unrefreshed, stiffness upon waking or after staying in one position for too long, concentration problems, difficulty remembering and performing simple mental tasks (“fibro fog“), abdominal pain, bloating, nausea, constipation alternating with diarrhea (irritable bowel syndrome), tension or migraine headaches, jaw and facial tenderness. With fibromyalgia comes sensitivity to odors, noises, bright lights, medications, certain foods, and cold. Fibromyalgia patients report feeling anxious or depressed, numbness or tingling in the face, arms, hands, legs, or feet, increase in urinary urgency or frequency (irritable bladder), reduced tolerance for exercise and muscle pain after exercise, and a feeling of swelling (without actual swelling) in the hands and feet.

The cause of fibromyalgia is largely theorized, as it is not well understood. Researchers and doctors believe that a fibromyalgia patient experiences amplified pain as a result of abnormal sensory processing in the central nervous system. Much research has detected physiological abnormalities in fibromyalgia, including increased levels of substance P in the spinal cord, low levels of blood flow to the thalamus region of the brain, HPA axis hypofunction, low levels of serotonin and tryptophan, and abnormalities in cytokine function. Other fibromyalgia triggers include genetic factors and traumatic events or injuries.

Similar to fibromyalgia, the exact cause of polymyalgia is unknown, but genetics and environmental exposure have been theorized to play a role in its development. Certain gene variations have been found to increase a person’s likelihood of developing polymyalgia, and new cases of polymyalgia often cycle with the seasons. This suggests that there are environmental triggers for polymyalgia such as viruses, but no specific virus has been detected yet.

There is another theory that giant cell arteritis and polymyalgia may be affiliated because of their similarities. Nearly 20 percent of polymyalgia patients show signs of giant cell arteritis, and nearly half of giant cell arteritis patients may have polymyalgia. More research is needed to explore this connection.

Symptoms of polymyalgia include aches and pains in the shoulders, aches and pains in the neck, upper arms, buttocks, hips or thighs, stiffness in affected areas, particularly in the morning, limited range of motion, pain or stiffness in the wrists, elbows and knees, mild fever, fatigue, malaise, loss of appetite, unintended weight loss, and depression.

Fibromyalgia vs. polymyalgia: Diagnosis and medication

There isn’t a specific test for fibromyalgia, but doctors may use a form of testing that checks 18 specific trigger points that have been found to be present in majority of fibromyalgia patients. Not all doctors use trigger point exams anymore, but rather they narrow down on a fibromyalgia diagnosis if a person has experienced widespread pain for at least three months. Your doctor may also refer you for some blood work to rule out other conditions.

Similar to fibromyalgia, polymyalgia requires several different tests in order to narrow down on a proper diagnosis. Some of those tests include physical exams and medical history review, blood tests for complete blood count and inflammation indicators, imaging tests to distinguish polymyalgia from other conditions with similar symptoms, and monitoring for giant cell arteritis by paying close attention to the presence of headaches, jaw pain, tenderness, blurred or double vision, and scalp tenderness.

Polymyalgia typically uses corticosteroids as a mode of treatment, whereas fibromyalgia may utilize a combination of medications in order to reduce and ease pain.

Treatment options for fibromyalgia and polymyalgia

Treating fibromyalgia can be difficult, as its exact cause is unknown. Therefore, the goal of fibromyalgia treatment is symptom management. A doctor may prescribe analgesics, or painkillers, to address fibromyalgia. However, there is a risk of developing addiction to these drugs, so doctors may recommend this option with caution. Nonsteroidal anti-inflammatory drugs (NSAIDs) can also be taken for pain management, but once again long-term use of these drugs can yield unwanted side effects. In some cases, antidepressants may be prescribed as well.

Some alternative and complementary therapies and treatments for fibromyalgia include massages, acupuncture, cognitive behavioral therapy, movement therapies, and chiropractic.

Low-dose corticosteroids are used to treat polymyalgia and symptom relief can start within the first three days. If you do not respond to corticosteroids, your doctor may refer you to a rheumatologist. Long-term use of corticosteroids can increase the risk of health complications, so your doctor will want to keep your dosages low and eventually take you off the medication.
While you are on corticosteroids, your doctor will monitor you to ensure no complications occur. Coming off the medications too quickly can result in a relapse, so it must occur gradually.

Some common side effects include weight gain, osteoporosis, high blood pressure, diabetes, and cataracts. Your doctor may recommend calcium and vitamin D supplementation as a means to prevent osteoporosis. They may also recommend getting vaccinated for pneumonia and taking an immunosuppressant drug if corticosteroids are not effective or in case of relapse.

Patients may benefit from physical therapy, too, as a means of regaining strength and coordination and getting back to their daily tasks.