This chapter discusses common rheumatologic diseases that have predominantly musculoskeletal presentations; however, all of these conditions have cutaneous manifestations.
Affects roughly 1% of the world population.
Chronic, disfiguring, inflammatory condition.
Genetics and environment play a role in etiology.
Symmetric arthritis of the proximal interphalangeal and metacarpophalangeal joints most common.
Skin findings quite varied, including papules, plaques, and nodules with multiple histologic types, vasculitis/Bywaters lesions, pyoderma gangrenosum/Felty ulcers.
Treatment based on severity of disease.
Rheumatoid arthritis (RA) is a systemic inflammatory autoimmune disease that is characterized by debilitating chronic, symmetric polyarthritis. Important extraarticular manifestations are many, including, in part, rheumatoid nodules, pyoderma gangrenosum, granulomatous and other skin lesions, vasculitis, and internal organ involvement. The disease process is often progressive, resulting in limitation of joint function, decline in functional status, and possibly premature death. Permanent remission is unusual.
The revised diagnostic criteria approved in 2010 by the board of directors of the American College of Rheumatology and the executive directors of the European League Against Rheumatism focuses on identifying patients earlier in the course of their disease than was allowed by previous criteria.1 Table 66-1 outlines these revised criteria. Even though cutaneous findings may be a key to diagnosis, none are considered diagnostic as no extraarticular physical findings are included in the criteria.
Table 66-12010 American College of Rheumatology/European League Against Rheumatism Classification Criteria for Arthritisa |Favorite Table|Download (.pdf) Table 66-1 2010 American College of Rheumatology/European League Against Rheumatism Classification Criteria for Arthritisa
|Target population: patients who (a) have at least 1 joint with definite clinical synovitis (swelling), (b) with the synovitis not better explained by another disease.a |
|CLASSIFICATION CRITERIA FOR RHEUMATOID ARTHRITIS (RA) (ADD SCORE OF CATEGORIES A TO D; SCORE ≥6/10 IS NEEDED FOR DEFINITE RA CLASSIFICATION) ||SCORE |
|A. Joint Involvement: tender or swollen joint on examination, excluding distal IP joints, first MCP joints, and first MTP joints || |
| 1 large joint (shoulder, elbow, hip, knee, or ankle) ||0 |
| 2 to 10 large joints ||1 |
| 1 to 3 small joints (MCP, proximal IP, 2nd to 5th MTP, thumb IP, wrists) with or without large joints ||2 |
| 4-10 small joints with or without large joints ||3 |
| >10 joints (must have at least 1 small joint; other joints can include joints not specifically listed elsewhere, eg, TM, AC, SC) ||5 |
|B. Serology (at least 1 test result is needed for classification) || |
| Negative RF and negative ACPA ||0 |
| Low-positive RF or low-positive ACPAb ||2 |
| High-positive RF or high-positive ACPAb ||3 |
|C. Acute-phase reactants (at least 1 result needed for classification) || |
| Normal CRP and normal ESR ||0 |
| Abnormal CRP or abnormal ESR ||1 |
|D. Duration of symptomsc || |
| <6 weeks ||0 |
| ≥6 weeks ||1 |