American College of Rheumatology (ACR) criteria for the classification of fibromyalgia

Last reviewed 06/2023

the American College of Rheumatology (ACR) criteria for the classification of fibromyalgia

The American College of Rheumatology 1990 criteria for the classification of fibromyalgia (1)


1) History of widespread pain
Definition - pain is considered widespread when all of the following are present: pain in the left side of the body, pain in the right side of the body, pain above the waist, and pain below the waist. In addition, axial skeletal pain (cervical spine or anterior chest or thoracic spine or low back) must be present. In this definition, shoulder and buttock pain is considered as pain for each involved side. 'Low back' pain is considered lower segment pain

 

2) Pain in 11 of 18 tender point sites on digital palpation
Definition - pain, on digital palpation, must be present in at least 11 of the following 18 tender point sites:

  • occiput: bilateral, at the suboccipital muscle insertions
  • low cervical: bilateral, at the anterior aspects of the intertransverse spaces at C5-7
  • trapezius: bilateral, at the midpoint of the upper border
  • supraspinatus: bilateral, at the origins, above the scapulae spine near the medial border
  • second rib: bilateral, at the second costochondral junctions, just lateral to the junctions of the upper surfaces
  • lateral epicondyle: bilateral, 2cm distal to the epicondyles
  • gluteal: bilateral, in outer quadrants of buttocks in anterior fold of muscle
  • greater trochanter: bilateral, posterior to the trochanteric prominence
  • knee: bilateral, at the medial fat pad proximal to the joint line

Digital palpation should be performed with an approximate force of 4kg.
For a tender point to be considered 'positive' the subject must state that the palpation was painful. 'Tender' is not considered painful.

For classification purposes, patients will be said to have fibromyalgia if both criteria are satisfied.

  • widespread pain involving both sides of the body, above and below the waist as well as the axial skeletal system, for at least three months
  • presence of 11 tender points among the nine pairs of specified sites (18 points)

The presence of a second clinical disorder does not exclude the diagnosis of fibromyalgia
Note:

  • although quick and easy to do, 25% of patients diagnosed as having fibromyalgia did not have 11 tender points (2)

The American College of Rheumatology 2010 criteria for the classification of fibromyalgia (3)

The 31 point questionnaire was developed by ACR in 2010

  • it does not require a tender-point count
  • patients are assessed by
    • the widespread pain index (WPI) - divides the body into 19 regions and scores how many regions are reported as painful
    • a symptom severity score (SS) - assesses severity of fatigue, unrefreshing sleep, and cognitive symptoms
  • provides a severity scale for associated fibromyalgia symptoms (2,3).

A patient satisfies diagnostic criteria for fibromyalgia if the following 3 conditions are met:

  • widespread pain index (WPI) ≥7 and symptom severity (SS) scale score ≥5 or WPI 3 - 6 and SS scale score ≥9.
  • symptoms have been present at a similar level for at least 3 months.
  • the patient does not have a disorder that would otherwise explain the pain (3)

Reference:

Related pages:

fibromyalgia syndrome (FMS)