Fibromyalgia syndrome (FMS) is a chronic widespread muscular pain disorder that affects mostly women between the ages of 20 and 50, according to MedlinePlus. The pain and tender points can be found in soft tissues, such as muscles and tendons, and in joints. The cause is unknown, but many conditions may be seen in conjunction with FMS, such as sleep disorders, chronic fatigue syndrome, Lyme disease, depression, chronic neck pain and hypothyroidism.
Symptoms in addition to pain may include heart palpitations, difficulty with memory, alternating diarrhea and constipation, numbness in feet and hands, migraines and fatigue.
Criteria for Diagnosing Fibromyalgia
In 1990, the American College of Rheumatology defined 18 locations for pain points in fibromyalgia. At least 11 of the 18 had to be present, along with other criteria that must be met in order to determine the presence of FMS. These were the sole guidelines for FMS diagnosis until 2010 when the guidelines were revised.
The diagnostic criteria for FMS require three conditions to be met:
- Symptoms must be present for at least three months at a persistent level.
- No other disorder or disease process is present that would explain the pain.
- Either of the following must be present — a widespread pain index (WPI) of at least seven with a symptom severity (SS) scale score of five or more; or a WPI between three and six with an SS scale score of nine or more, as outlined in the following sections.
2010 Guidelines for Widespread Pain Index
The 1990 system did not take into account the fluctuation of symptoms and pain levels from one exam to another. In addition, it relied on the patient to report the pain level. The 2010 criteria include 19 areas of the body where pain is identified within a week of the examination with one point for each area. Per the American College of Rheumatology, this is the widespread pain index (WPI) and includes the following areas for a score between 0 and 19:
- Shoulder girdle, left and right
- Upper arm, left and right
- Lower arm, left and right
- Hip, left and right
- Upper leg, left and right
- Lower leg, left and right
- Jaw, left and right
- Upper and lower back
2010 Guidelines for Symptom Severity Scale Score
The symptom severity (SS) scale score requires the patient to rank specific symptoms from zero to three indicating the level of severity for the past week for fatigue, waking tired and cognitive symptoms as follows:
- 0 — no problem
- 1 — slight or mild problems, generally mild or intermittent
- 2 — moderate, considerable problems, often present and/or at a moderate level
- 3 — severe, pervasive, continuous, life-disturbing problems
In addition, the SS scale score includes the extent of symptoms such as irritable bowel syndrome, muscle pain, hearing difficulties, headache, dizziness, depression, change of taste, muscle weakness, heartburn, constipation, bladder spasms, nausea, blurred vision, fever, ringing in ears, dry mouth, mouth ulcers, itching, easy bruising, shortness of breath, rash, hair loss, difficulty thinking or remembering, abdominal pain, frequent urination, fatigue, numbness, insomnia, painful urination, nervousness, chest pain, sensitivity to sun, diarrhea, wheezing, hives, poor appetite, Raynaud's phenomenon, seizures, vomiting and dry eyes for a total possible SS scale score of 0 to 12.
MedlinePlus: Fibromyalgia https://www.nlm.nih.gov/medlineplus/ency/article/000427.htm
American College of Rheumatology: 1990 Criteria for the Classification of Fibromyalgia (Excerpt) https://www.rheumatology.org/practice/clinical/classification/fibromyalgia/fibro.asp
American College of Rheumatology: 2010 Preliminary Diagnostic Criteria (Excerpt) https://www.rheumatology.org/practice/clinical/classification/fibromyalgia/fibro_2010.asp