Soft tissue rheumatism - fibromyalgia and others
I’m not sure why these two conditions are in the same question, they don’t seem to have much in common! We shall address them separately.
Polymyalgia rheumatica
This is a subtle disease that is what is says, multiple pains in muscles. It is characterised by pain and stiffness of the neck, shoulder and pelvic girdles, which is especially worse in the morning. Additional symptoms include fatigue, anemia, flu-like feeling, low-grade fever and weight loss. Around 15% also have temporal (Giant Cell) arteritis (while about 50% of those with temporal arteritis have PR) and so screening should be done.
Boxes mark the typical sites of pain and stiffness in polymyalgia rheumatica: both shoulders and upper arms, and the pelvic girdle and hips.
Image: “Polymyalgia rheumatica man” by Twisp, Public domain, via Wikimedia Commons.
PR typically affects those over the age of 50, with a predilection of women. The cause of the disease is not well known, although it is understood that the pain and stiffness comes from the activity of inflammatory cells, which target muscles and tissues surrounding affected joints. There is a genetic link, although the nature of it is unknown. It is thought that there is a possible viral trigger (with viruses such as adenovirus, human parvovirus B19 and parainfluenza virus).
Stepwise plan:
- FBC, U&Es, LFTs, ESR, CRP and CK should all be done
- CRP and ESR will likely be raised, CK will be NORMAL!!!
Management
- Corticosteroids - generally a very good reaction
- 10-20mg prednisolone
- NSAIDs if additional symptom management required
Fibromyalgia
Fibromyalgia is a chronic pain syndrome of unknown aetiology. It is characterised by widespread pain and a heightened pain response to other pressure. Other symptoms include tiredness, sleep problems, numbness and tingling.
It is thought the disease results from abnormal sensory processing within the CNS, so called central sensitization and results from an amplification of peripheral sensory stimuli and a deficit of descending inhibitory control from the midbrain.
As well as always presenting with widespread pain, other important symptoms include low back pain, recurrent headaches, arthritis, muscle spasms, tingling and balance problems.
The condition generally occurs secondary to an acute injury, repetitive workload, persistent stress, infections and/or toxin exposure. It is not uncommon for regional pain to evolve into fibromyalgia. It is also a common occurrence following victims of post-traumatic stress disorder (childhood abuse and sexual trauma are often found in the history).