Polymyalgia rheumatica (PMR) and fibromyalgia are two distinct conditions that share some similar symptoms like muscle aches and joint pain. This can sometimes lead to one being mistaken for the other. While both cause widespread pain, there are some key differences between polymyalgia and fibromyalgia that can help differentiate between the two.
Some quick answers to introductory questions:
– What is polymyalgia rheumatica? Polymyalgia rheumatica is an inflammatory condition that causes muscle pain and stiffness, especially around the shoulders, neck, and hips.
– What causes polymyalgia? Experts believe polymyalgia is caused by inflammation of the synovial membranes around joints. While the exact cause is unknown, it likely involves immune system dysfunction.
– What are the main symptoms? The primary symptoms are pain and stiffness in the shoulders, hips, neck, and upper arms. Symptoms are usually worse in the mornings and improve with activity.
– Who develops polymyalgia? Polymyalgia mainly affects adults over 50 years old. It is more common in women than men.
– How is polymyalgia diagnosed? There is no definitive diagnostic test for polymyalgia. Doctors diagnose it based on symptoms, physical exam findings, and blood tests like ESR and CRP to check for inflammation.
What is Fibromyalgia?
Fibromyalgia is a disorder characterized by widespread musculoskeletal pain accompanied by fatigue, sleep, memory and mood issues. Researchers believe that fibromyalgia amplifies painful sensations by affecting the way your brain and spinal cord process painful and non-painful signals.
Some quick answers on fibromyalgia:
– What causes fibromyalgia? The exact cause of fibromyalgia is unknown but likely involves a combination of genetics, infections, trauma and emotional stress.
– What are the main symptoms? The primary symptom is pain and tenderness throughout the body. Other symptoms include fatigue, sleep problems, memory issues, anxiety, and depression.
– Who develops fibromyalgia? Fibromyalgia can affect anyone but occurs more often in middle-aged women.
– How is it diagnosed? There are no definitive diagnostic tests for fibromyalgia. Doctors diagnose based on symptoms after ruling out other conditions. Diagnostic criteria include widespread pain for at least 3 months.
Similarities Between Polymyalgia and Fibromyalgia
Despite being distinct conditions, polymyalgia and fibromyalgia share some overlapping symptoms that can make distinguishing between the two tricky at times. Some of the key similarities include:
– Both cause body aches and pain – The hallmark of both conditions is pain and stiffness in muscles and joints throughout the body. The pain is often described as “deep muscle aching”.
– Pain is widespread – In both disorders, pain typically occurs on both sides of the body rather than being isolated to one area or joint.
– Morning stiffness is common – Patients with both polymyalgia and fibromyalgia frequently report stiffness that is most noticeable in the mornings.
– Fatigue is a problem – Persistent tiredness and difficulties with sleep are often seen in both polymyalgia and fibromyalgia.
– More common in middle-aged and older women – Both conditions occur more frequently in women and tend to arise in middle to later years of life.
– Emotional distress can occur – Anxiety, frustration and depression are not uncommon secondary consequences of dealing with chronic widespread pain.
Differences Between Polymyalgia and Fibromyalgia
Despite the overlapping features, there are some distinct differences between polymyalgia and fibromyalgia that help set them apart:
Location of Pain
While both conditions cause body-wide aches and pain, the location of pain tends to be different:
– Polymyalgia rheumatica tends to cause pain focused in the neck, shoulders, upper arms, hips, and thighs.
– Fibromyalgia causes more widespread pain including the neck, shoulders, back, hips, arms, and legs. Pain is often more generalized.
Morning Stiffness
– In polymyalgia, morning stiffness tends to be most pronounced in the shoulders and hips, often quite severe, and slow to improve.
– Fibromyalgia morning stiffness is more generalized, not necessarily focused in any single area, and tends to improve more quickly with movement.
Age of Onset
– Polymyalgia onset is unusual under the age of 50. Most cases arise in people over 70 years old.
– Fibromyalgia can occur at any age including childhood but is most common between 30 and 50 years old.
Presence of Inflammation
– Polymyalgia rheumatica involves active inflammation of joints and connective tissues that can be detected via blood tests. ESR and CRP levels are usually elevated.
– Fibromyalgia does not feature measurable inflammation – ESR and CRP are typically normal.
Response to Treatment
– Polymyalgia often responds rapidly and dramatically to low doses of corticosteroids like prednisone. Pain and stiffness improve within days to weeks.
– Fibromyalgia does not respond to corticosteroids. Symptoms are treated with other medications like pregabalin, duloxetine, or low dose tricyclic antidepressants. Improvement tends to be gradual.
Associated Conditions
– Polymyalgia is closely associated with giant cell arteritis (temporal arteritis), sometimes considered two manifestations of the same disease.
– Fibromyalgia does not have direct links to arteritis but can co-occur with conditions like chronic fatigue, irritable bowel syndrome and anxiety/depression.
Diagnostic Process
Since the symptoms have considerable overlap, doctors will usually evaluate for both polymyalgia and fibromyalgia when a middle-aged or older person presents with new onset widespread muscle pain and stiffness. Some key aspects of the diagnostic workup include:
– **Medical history** – The doctor obtains detailed information about the onset and location of pain, stiffness, fatigue and other symptoms. Patterns like morning stiffness and response to activity provide helpful clues.
– **Physical exam** – The physician checks for localized tenderness in muscles and joints, evaluates range of motion, and looks for reduced strength or muscle atrophy.
– **Blood tests** – Complete blood count, ESR, CRP and muscle enzymes are tested. Elevated inflammatory markers like ESR and CRP point to polymyalgia as the more likely diagnosis.
– **Manual tender point survey** – The doctor will press on specific spots on the neck, back, shoulders, hips, arms and legs looking for excessive tenderness. Widespread tenderness suggests fibromyalgia.
– **Ruling out other disorders** – The doctor considers other potential causes like osteoarthritis, autoimmune diseases, thyroid disorders, or polymyositis. These may be excluded using imaging, blood tests or muscle biopsy.
– **Response to treatment** – A doctor may prescribe a low dose corticosteroid trial. Substantial improvement within a few weeks indicates polymyalgia as opposed to fibromyalgia.
Can Fibromyalgia and Polymyalgia Co-Exist?
It is certainly possible for someone to have both fibromyalgia and polymyalgia rheumatica. Studies show that between 15-30% of people diagnosed with polymyalgia also fulfill diagnostic criteria for fibromyalgia. The odds of having both appear especially high in women over age 70.
When concurrent fibromyalgia and polymyalgia occur, patients will typically experience:
– Widespread pain, achiness, soreness characteristic of fibromyalgia plus
– More severe stiffness and pain concentrated in the neck, shoulders, hips and thighs typical of polymyalgia
This combination can be more difficult to treat. The prednisone used for polymyalgia is generally not beneficial for fibromyalgia pain. Other medications like gabapentin or tricyclic antidepressants may be needed to address the fibromyalgia symptoms.
Conclusion
In summary, while fibromyalgia and polymyalgia rheumatica share some similar symptoms like morning stiffness and body-wide pain, there are important differences in the location of pain, age of onset, presence of inflammation, and response to treatment that help distinguish between the two. Doctors will need to investigate symptoms, conduct physical exams, and order appropriate lab tests to arrive at an accurate diagnosis when both are possible. Being aware of the overlapping features as well as the distinct characteristics of each condition allows for proper diagnosis and management.