Generality
Fibromyalgia is a syndrome with multiple symptoms that can occur together, including widespread pain, decreased pain threshold, debilitating fatigue and anxiety. The cause that causes this condition is not yet known, but the involvement of particular alterations of neurotransmission, which induce an incorrect interpretation of painful stimuli, has been highlighted.
Diagnosis
Fibromyalgia is largely under-diagnosed: it is estimated that on average five years are required for a fibromyalgia patient to get an accurate diagnosis. On a diagnostic level, framing a pathology of this type is extremely complex: many symptoms are non-specific and can mimic the clinical presentations of other pathological conditions. Furthermore, no specific laboratory tests are available to confirm the diagnosis of fibromyalgia.
Doctors formulate the diagnosis using information obtained with:
- Patient's clinical history;
- Self-reported symptoms;
- Complete physical examination;
- Manual evaluation of sensitive points (tender points).
During the diagnosis, the doctor also assesses the severity of related symptoms, such as fatigue, sleep disorders and mood disorders. This assessment helps to measure the impact of fibromyalgia on physical and emotional function, as well as the patient's general health status. In fibromyalgia, the differential diagnosis plays a major role , as the doctor will have to rule out other conditions that can cause similar symptoms. Another key point to be considered is that the presence of other diseases, such as rheumatoid arthritis or systemic lupus erythematosus, does not rule out a diagnosis of fibromyalgia.
history
Very often the anamnesis produces a confused or not completely clear presentation. Fibromyalgia is a chronic and often long lasting disorder. The patient certainly presents important symptomatic precedents, but often not accompanied by evidence of illness (ie the diagnosis failed to define the disease). Also for this reason, the patient is followed by more specialists: rheumatologists, neurologists, chronic pain therapists and so on.
Although the clinical history of each patient may be very different, fibromyalgia usually develops progressively with:
- A reduction in muscle function;
- A state of pain or discomfort;
- A limitation not justified, from the clinical and functional point of view, in the execution of the movement.
The anamnesis is also useful to bring out an association between the symptomatology and specific physical or emotional events that may have triggered fibromyalgia, such as trauma, family problems, altered emotional states and stress.
Physical examination
The picture can be very variable from patient to patient. Fibromyalgia presents in any case a muscular and tendon aetiology. The physical examination does not show any particular signs, but tends to register an alteration of the sensitivity of the limbs or other parts of the body: by exerting pressure, even slight, in certain sensitive points (tender points), it is possible to evoke even acute pain . These sensitive points are not random and are generally characterized by the fact that, in the healthy subject, their stimulation does not induce particular reactions (or at least not in all points). In terms of tender points, regions of contracture or alterations of the gross anatomy of the muscle can be found. Neurological examination has no specific signs of nervous pathology.
ACR criteria for diagnosis
In 1990, the American College of Rheumatology (ACR) established two criteria for the diagnosis of fibromyalgia:
- Widespread pain lasting at least three months;
- Positive tenderness to digital palpation in at least 11 of the 18 tender points.
The problem with these diagnostic criteria is that they are too focused on the physical aspect of fibromyalgia and this approach can potentially generate diagnostic errors, in fact:
- Painful symptoms can be very variable over time, even from one day to the next;
- Patients do not always manifest widespread tenderness to the whole body;
- For the precise search for tender points a certain manual skill is required: the pressure could be exerted on wrong anatomical points or with excessive force.
Today, the diagnosis is based on a more comprehensive assessment of the patient.
In general practice the most recent diagnostic criteria include the evaluation of:
- Widespread pain lasting at least three months;
- Related symptoms, such as fatigue, sleep disorders and mood disorders;
- Stress conditions;
- No other underlying condition that could cause pain;
- Blood tests and other laboratory tests, to exclude pathological conditions with a similar clinical picture.
Finally, the diagnosis can be formulated even in the presence of some tender points, as long as they are associated with characteristic accompanying symptoms.
Laboratory tests
There are no specific laboratory tests that confirm the diagnosis of fibromyalgia, but the doctor may decide to investigate the clinical definition of the disorder with some investigations that allow the exclusion of other conditions from similar symptoms.
These conditions include:
- Vitamin D deficiency;
- Hypothyroidism (low levels of hormones due to hypoactivity of the thyroid gland);
- Diseases of the parathyroid glands (which influence the level of calcium in the blood, for example: hyperparathyroidism);
- Muscular diseases, such as polymyositis;
- Hypercalcemia (excessive levels of calcium in the blood);
- Infectious diseases such as hepatitis and AIDS .;
- Diseases and bone deformations (example: Paget's disease);
- Neoplasms.
Blood tests can therefore include:
- Complete blood count;
- Thyroid function test (TSH, FT4) and blood calcium level;
- ESR (erythrocyte sedimentation rate), PCR (C-reactive protein), ANA test (antinuclear antibodies), rheumatoid factor (RF);
- Creatine phosphokinase (CPK);
- Alkaline phosphatase (ALP);
- Transaminases, anti-EBV and anti-HCV antibodies;
In general, in fibromyalgia the laboratory parameters tend to be normal and serve mainly to exclude other rheumatic diseases. For example:
- In the case of fibromyalgia, the erythrocyte sedimentation rate (ESR) is usually normal;
- Fibromyalgic ANAs are usually not elevated (even if detectable in 10% of cases), whereas they are commonly found in systemic lupus erythematosus;
- Rheumatoid factor (FR) is positive in most patients with rheumatoid arthritis;
- Polymyositis is distinguished by increased levels of CPK and muscle enzymes.
Finally, any radiological changes that can be detected in the articular area are to be attributed to the concomitant rheumatic pathology (example: arthritis).
