Systemic lupus erythematosus (SLE) is a multisystemic, autoimmune, rheumatic disease involving the joints and skin in up to 90% of affected individuals. SLE affects various organ systems simultaneously, and its course is typically recurrent, with periods of relative remission followed by relapses. Hand involvement is a common manifestation and can vary considerably from mild arthralgia to severely deformed hands. Treatment varies widely depending on the systemic involvement and disease severity, but conservative management generally focuses on a course of disease-modifying antirheumatic drugs (DMARDs) and other pharmacologic interventions, while surgical procedures like tendon rebalancing, arthrodesis and arthroplasty are typically reserved for patients with advanced deformity and severe functional impairments.1,2
Pathophysiology
- Genetic, epigenetic, ethnic, immunoregulatory, hormonal, and environmental factors are all believed to be associated with its development
- Many innate and acquired immune disturbances occur in SLE and are therefore proposed mechanisms of its pathophysiology
- T- and B-cell hyperactivation, increased apoptosis, defective immune complex clearance, high ratio of CD4:CD8 T-cells, and impaired autoimmune tolerance3
- SLE arthritis is traditionally considered to be mild, reversible, and non-erosive
- 5–15% of cases progress to deforming arthropathy, which is either erosive as in rhupus syndrome or non-erosive as in Jaccoud’s arthropathy5
- Jaccoud’s arthropathy is characterized by subluxation of metacarpophalangeal (MP) joints, ulnar deviation, swan neck deformity, and thumb deformity due to changes in soft tissues
- Joint deformities in the hand occur as a result of ligament and volar plate laxity, as well as extensor tendon subluxation, resulting in an imbalance of forces acting on the joints. The deformity is actively correctible initially but may progress to a fixed deformity.
- The characteristic deformity at the MCP joint is flexion, with ulnar deviation and volar subluxation resulting from extensor tendon subluxation ulnar to the metacarpal head.
- Progressive volar shift of the extensor tendon causes the proximal phalanx to subluxate volarly.
- Intrinsic muscle shortening, especially of the ulnar muscles, occurs as a result of the volar subluxation of the proximal phalanx and MCP joint ulnar deviation.
- The resultant intrinsic tightness causes hyperextension deformity at the proximal interphalangeal joint.
- Clinically, the patient progresses from being able to extend the affected MCP joints actively to loss of active extension but maintenance of passive extension.
- In later stages, the deformity may become fixed with an inability to extend the MCP joints even passively.
Related Anatomy
- MP joints
- Interphalangeal (IP) joints
- Hand flexor tendon
- Wrist joint
- Wrist flexor tendon
- Wrist extensor tendon
Incidence
- SLE typically presents between ages 15-44 years and has a prevalence of ~5.8-130 per 100,0006, with ≥1.5 million Americans currently affected7
- SLE is 2-3 times more prevalent in African-Americans than in Caucasians, and it is 10 times more common in females than in males8
- Inflammatory musculoskeletal involvement is one of the most common manifestations of SLE, affecting up to 95% of patients9
- Most important predictors of disease progression are older age at diagnosis, African-American race, and low income4
- Possible risk factors include cigarette smoking, administration of estrogen to postmenopausal women, exposure to UV light, diabetes, and being overweight3
Related Conditions
- Rheumatoid arthritis
- Rhupus syndrome
- Jaccoud’s arthropathy
- Leukemia
- Leukopenia
- Anemia
- Osteoarthritis
- Kidney disease
- Pericarditis
- Myocarditis
- Atherosclerosis
- Pleuritis
- Pancreatitis
- Central nervous system disease
- Osteonecrosis
- Vision problems
- Raynaud’s phenomenon
- Vasculitis
- Osteoporosis
- Antiphospholipid syndrome
- Ophthalmologic involvement
- Carpal tunnel syndrome
- Trigger finger
- The most frequently affected joints are the MP, IP, wrist, and knee joints9
Differential Diagnosis
- Adult-onset Still disease
- B-cell lymphoma
- Behçet syndrome
- Chronic fatigue syndrome
- Dermatomyositis
- Endocarditis
- Epstein-Barr virus
- Fibromyalgia
- Hepatitis C
- HIV infection
- Inflammatory bowel disease
- Kikuchi's disease
- Lyme disease
- Mixed connective-tissue disease
- Multiple sclerosis
- Polymyositis
- Psoriatic arthritis
- Reactive arthritis
- Rheumatoid arthritis
- Rhupus
- Sarcoidosis
- Scleroderma
- Serum sickness
- Sjögren’s syndrome
- Systemic sclerosis
- Thrombotic thrombocytopenia purpura
- Thyroid disease
- Undifferentiated connective-tissue disease
- Vasculitis
Special Laboratory Work-up Diagnosis
- The initial evaluation should include:
- Complete blood count (CBC)
- Comprehensive metabolic panel (CMP)
- Urinalysis with microscopy (UA)
- Antiphospholipid antibodies
- Acute phase reactants ie. Estimated sedimentation rate (ESR) and C-reactive protein (CRP)
- Serum creatinine and estimated glomerular filtration rate (eGFR)
- Antinuclear antibody (ANA) test4 -- if this is positive, additional tests to be ordered:
- C3 and C4 complement or CH50 level tests
- Anti-dsDNA antibodies
- Anti-sm antibodies
- Anti-Ro/SSA and Anti-La/SSB
- Anti-U1RNP antibody
- Antiribosomal P protein antibody