Distinguishing inflammatory pain from centralized pain
| Feature | Inflammatory pain | Centralized pain |
| Location | Hands, wrists, cervical spine, knees, hips, ankles, feet | More diffuse, “all over,” tender points |
| Relationship to time of day | Nocturnal, with rest, early morning | Nocturnal, with rest, early morning |
| Relationship to exertion | Better with exertion | Better during exertion, worse after |
| Character of pain | Constant, dull, achy | Intermittent, stabbing, burning, “like being hit by a truck,” “unbearable” |
| Duration | Variable | Often many years |
| General associated symptoms and signs | Fatigue, fever, other organ signs and symptoms | Fatigue, weakness, headaches, irritable bowel syndrome symptoms, cognitive impairment, disturbed sleep, mood disorders, dry eyes and mouth, light sensitivity, difficulty swallowing, sensation of swollen glands in neck, urinary frequency, feeling faint after hot shower or in hot weather |
| Localized associated symptoms and signs | Stiffness ≥ 60 minutes Objective swelling | Stiffness ≥ 60 minutes Lack of objective findings Tender points Allodynia (pain from normally nonpainful stimuli), hyperalgesia (increased sensitivity to pain) Acrocyanosis (bluish coloring of hands and feet) Brisk reflexes |
| Laboratory results | Inflammatory picture: elevated C-reactive protein and Westergren sedimentation rate, anemia, occasionally elevated platelet count, positive serologies (rheumatoid factor, anti-cyclic citrullinated peptide, extractable nuclear antigen panel) | Normal |