Fibromyalgia and polymyalgia are two conditions presenting similar signs and symptoms. Even experienced clinicians have difficulty in differentiating these two conditions. Despite similar presentations, there are some differences between the two, which are discussed below in detail while highlighting the clinical features, symptoms, causes, investigation and diagnosis, prognosis, and the course of treatment of fibromyalgia and polymyalgia individually.
Polymyalgia
The literal meaning of polymyalgia is pain in multiple muscles. This is indeed one of the principle symptoms of a complex condition. The correct name of the condition is polymyalgia rheumatica. This is a common condition among the elderly, especially people over 70 years old. It presents with bilateral pain, stiffness in shoulders and proximal limb muscles.
To diagnose, this should last for more than one month. Individuals with polymyalgia may also have mild inflammation of more than one joint, inflammation of tendons and joint capsules of affected joints, depression, fatigue, fever, weight loss, and loss of appetite. Symptoms may themselves manifest suddenly or slowly over a month. This condition is somewhat similar to giant cell arteritis. Polymyalgia rheumatic is more common in females. It is actually twice common in females than males. Erythrocyte sedimentation rate (ESR) is usually above 40mm per hour. Creatine is a muscle enzyme, which can enter the bloodstream in extensive muscle damage condition. In polymyalgia, rheumatic creatine level is normal. Alkaline phosphatase level may be high. This condition may be confused with hypothyroidism (low thyroid hormones), recent onset rheumatoid arthritis, primary muscle diseases, occult malignancy, neck lesions, bilateral sub-acromial impingement lesions, and spinal stenosis.
Polymyalgia rheumatic is treated with high doses of prednisolone. Initial high doses may be reduced with time. This condition may need continuous treatment for more than two years. Complications are mostly due to chronic steroid intake. High blood sugar levels, osteoporosis, skin thinning are a few known complications.
Fibromyalgia
Fibromyalgia literally means muscle and connective tissue pain. Fibromyalgia is characterized by long standing pain and increased sensitivity to deep pressure at points all over the body. This condition is of unknown origin. Scientists believe that psychological, neurological, biological, genetic and environmental factors are responsible for the disease mechanism. Individuals with fibromyalgia may also have severe fatigue, disturbance of sleep, stiffness of joints, swallowing difficulty, constipation / diarrhea, urinary symptoms, skin numbness and tingling, loss of higher mental functions. Usually fibromyalgia is coexistent with psychiatric conditions like depression, anxiety and stress disorders.
The symptomatology of fibromyalgia is vast, and unsurprisingly all patients with fibromyalgia do not experience all the symptoms. About 2-4% of the population is thought to have the condition. This is about 9 times as common in females compared to men. There are four types of fibromyalgia. They are characterized as, extreme pain sensitivity without psychiatric conditions, fibromyalgia with comorbid with pain related to depression, depression with concomitant fibromyalgia syndrome and fibromyalgia due to somatization. There is no diagnostic test to identify the disorder.
Management options include cognitive behavioral therapy, pregabalin, duloxetine and milnacipran.
What is the difference between Fibromyalgia and Polymyalgia?
• Polymyalgia causes resting muscle pain while fibromyalgia causes increased pain in deep pressure.
• Polymyalgia is common among the elderly while fibromyalgia is commoner in the middle aged individuals.
• While both conditions are associated with psychiatric conditions, fibromyalgia features abnormal higher mental functions than polymyalgia.
• Polymyalgia responds to steroids while fibromyalgia needs more specific treatment methods.
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