"Swan-Neck Deformity" – (Ulnar Deviation & Subluxation of the MCP Joints)
Ankylosis (Fusion) & Restriction of movement $\to$ Muscle Wasting
Dermatologic - Rheumatoid Nodules (e.g., Elbows)
Vasculitis - Digital Infarcts (can cause gangrene)
Ophthalmologic - Dry eyes, Scleritis
Pulmonary - Fibrosis, lung nodules, pleuritis, effusion
Cardiac - pericarditis, pericardial effusion, valvular defects, conduction defects
GI - PUD (from NSAIDS), dry mouth
Renal - Amyloidosis $\to$ Proteinuria
Hepatic - Nodules (Nodular regenerative hyperplasia), portal fibrosis
Neurologic - Cervical spine instability, peripheral nerve entrapment
Haematologic - Lymphadenopathy, splenomegaly and leukopenia, amyloidosis, anaemia.

Diagnosis:

Diagnostic Criteria: (Requires $4^*$ of the Following Features for Diagnosis)
- Morning Stiffness
- $>3$ Joints
- MCP/PIP/Wrist Joints.
- Symmetrical Arthritis
- Rheumatoid Nodules in Skin
- RA Seropositivity (Rheumatoid Factor in Serum)
- X-Ray Changes: Erosions
Lab:
- Old - Serum Rheumatoid Factor Positive (Anti-IgG IgM Antibodies) - Hence "Seropositive"
- New - ACCP - ("Anti-Cyclic Citrullinated Peptide Antibody Test) $95\%$ Specificity
- + Elevated ESR

Treatment:

Etiology:
- Joint Infection
- Common Bugs - N. gonorrhoeae, S. aureus, Other less commons.
Pathogenesis:
- Routes of Spread - Hematogenous (Commonest), Direct from Adjacent Tissue, Iatrogenic.
Clinical Features – A Medical Emergency!
- (If Gonococcal $\to$ Preceding Bacteremia with Maculopapulovesicular Skin Lesions & Migrating Polyarthritis $\to$ Settling into Monoarthritis - Typically Knee)
- Typically Severe Mono-Arthritis. (Joint often held in slight flexion to $\downarrow$ Pain)
  - Swelling, Erythema, Hot, $\downarrow$ ROM due to Pain
- + Fever + Malaise
- (+/- Signs of Acute Sepsis – Fever, Chills, Dehydration, Lethargy)
Diagnosis:
- Joint Aspirate + MCS.
  - (Crystals?, Gram Stain?)
- FBC ($\uparrow$ WBC)
- $\uparrow$ ESR, CRP
- Endocervical/Urethral Swab or Urine PCR for Gonococcal.
Treatment:
- If Gonococcal - Azithromycin, Ceftriaxone or Doxycycline
- If Staph - Ampicillin, Erythromycin or Vancomycin
- Analgesia
- Arthroscopy - Aspiration & Washout
- (+/- Surgical Debridement/Joint Replacement)
- (NB: DO NOT USE Intra-Articular Steroids!!)
Co