Reactive Arthritis (Reiter Syndrome)

• Reactive arthritis is an autoimmune response triggered by a prior infection, where the immune system continues to attack the body after the infection has cleared.
  • Most commonly GI or GU infection, with Chlamydia being the most common culprit.
• Typically ages 20 – 40 years old.
• Affects males more frequently than women.

Clinical Presentation

• “I can’t see, I can’t pee, and I can’t climb a tree,” which reflects the following symptoms:
  • Conjunctivitis
  • Urethritis
  • Joint inflammation typically involving large joints
  • Lesions on Hands and Feet
• Enthesitis (inflammation at sites where tendons or ligaments attach to bone)
• Low back pain
• Sacroiliitis

Labs, Studies, and Physical Exam Findings

• Culture the Urethra/Cervix: To identify the causative agent, typically Chlamydia
• Rheumatoid Factor: Will be negative in reactive arthritis.
• Elevated C-reactive Protein.
• HLA-B27: Approximately 75% of patients with reactive arthritis will test positive for HLA-B27, not diagnostic.

Treatment

• Address the Underlying Infection: Treat the underlying infection
  • Chlamydia – azithromycin
• NSAIDs: pain relief and to reduce inflammation.
• Steroids: In severe cases to help with inflammation.

Differential Diagnosis

• Rheumatoid arthritis, psoriatic arthritis, and reactive arthritis triggered by infections other than Chlamydia

Rheumatoid Arthritis (RA)

• Rheumatoid Arthritis (RA) is a chronic autoimmune disease characterized by inflammation of the synovium (the lining of joints), leading to joint damage and pain.
• Women are affected more frequently than men.
• RA is a systemic condition, which can affect any organ or tissue.

Clinical Presentation

• Typically affects the small joints of the hands and feet.
• Stiffness – most prominently in the morning.
• Joint Pain
• Deformities in the hands and feet.

Labs, Studies, and Physical Exam Findings

• Joint Examination:
  • Swollen Joints.
  • Stiff Joints.
  • Multiple small joints involved.
  • Most commonly hands, feet, and cervical spine.
  • Ulnar deviation – displacement of the fingers medially.
  • Swan neck deformity – PIP hyperextension with DIP flexion.
  • Boutonniere deformity – PIP flexion with DIP hyperextension.
  • Hammertoes are also very common.
• Rheumatoid Nodules
  • Usually painless, firm lumps or masses that can develop under the skin.
• X-rays
  • Joint space narrowing
  • Joint deformities
  • Bone erosion
  • C spine involvement:
    • Atlantoaxial subluxation in Rheumatoid Arthritis (RA) is the abnormal movement of the first and second cervical vertebrae that can potentially lead to neck instability and spinal cord compression. You MUST get an x-ray of the c-spine before a patient is intubated for surgery to assess the risk.
• Immunologic studies:
  • Rheumatoid factor
  • Anti-citrullinated protein antibodies (ACPAs) or anti-CCP.
  • Anti-nuclear antibody (ANA).
• CBC.
• C-reactive protein.
• Clinical Diagnosis Criteria:
  • Two or more swollen joints.
  • Morning stiffness lasting more than one hour for at least six weeks.
  • Rheumatoid factors or autoantibodies against ACPA. – A negative autoantibody result does not exclude a diagnosis of RA.

Treatment

• NSAIDS.
• COX-2 inhibitors (Celecoxib – Celebrex).
• Disease-modifying antirheumatic drugs (DMARDS):
  • Methotrexate is usually first line (It is teratogenic).

Differential Diagnosis

• Osteoarthritis, systemic lupus erythematosus (SLE), psoriatic arthritis,gout and pseudogout, infectious arthritis

Systemic Lupus Erythematosus (SLE)

• A complex autoimmune disease that can affect multiple organs and systems in the body.
• SLE impacts females six times as frequently as males.
• SLE affects African Americans more frequently than Caucasians.

Clinical Presentation

• Joint pain is a common symptom, with the hands, wrists, and knees being the most frequently affected joints.
• General malaise and fatigue.
• Fever – due to immune response.
• Chest pain – secondary to pericarditis
• “Butterfly rash" across the cheeks and nose being a classic sign of SLE.
• Mouth sores
• Photosensitivity

Labs, Studies, and Physical Exam Findings

• Butterfly Rash across the cheeks and nose
• Complete Blood Count (CBC)
• Blood Urea Nitrogen/Creatinine (BUN/CR) levels
• Urinalysis
• Erythrocyte Sedimentation Rate (ESR)
• Complement levels
• Anti-Nuclear Antibody (ANA) Test: While ANA is present in 100% of SLE cases, it is not specific to SLE and therefore not diagnostic.

Treatment

• NSAIDs for pain relief and inflammation control.
• Hydroxychloroquine
  • Reduces Inflammation and flares ups of SLE
  • Reduces immune system overactivity
• Corticosteroids

Differential Diagnosis

• Rheumatoid Arthritis (RA), Sjögren’s Syndrome, Dermatomyositis, Systemic Sclerosis (Scleroderma), Multiple Sclerosis (MS)

Systemic Sclerosis (Scleroderma)

• Etymology: “Sclero” means hardening, and “derma” refers to the skin.
• Subtypes:
  • Limited Scleroderma (CREST Syndrome):
    • C – Calcinosis (nodules under the skin)
    • R – Raynaud’s
    • E – Esophageal problems (difficulty swallowing)
    • S – Sclerodactyly (thickening of the skin on fingers)
    • T – Telangiectasias (dilated blood vessels)
  • Diffuse Scleroderma:
    • Affects larger skin areas and one or more organ systems.

Clinical Presentation

• Calcinosis: Development of nodules under the skin.
• Raynaud’s Phenomenon: Fingers or toes turn blue and white in response to cold or stress.
• Skin Thickening: Skin becomes thick and hard.
• Esophageal Issues: Difficulty swallowing.
• Chest pain or shortness of breath: May indicate involvement of the heart or lungs.
• Dry cough.
• Joint pain and decreased range of motion.

Labs, Studies and Physical Exam Findings

• Thickened Skin: On physical examination.
• Raynaud’s: Characterized by color changes in extremities.
• Telangiectasia
• Rheumatoid factor: Negative
• Anti-nuclear antibody (ANA): typically positive
• C Reactive protein: