Differential Diagnosis for Chronic Inflammatory Arthritis
Single Most Likely Diagnosis
- Crystal-induced arthritis (e.g., gout, pseudogout): This is often the most common cause of acute and chronic inflammatory arthritis, especially in the context of oligoarticular or polyarticular presentations. The presence of crystal-induced arthritis can be suggested by the sudden onset of intense pain, redness, and swelling in a joint, often with a history of similar episodes.
Other Likely Diagnoses
- Lyme arthritis: Caused by the bacterium Borrelia burgdorferi, transmitted by ticks. It typically presents with a distinctive "bull's-eye" rash (erythema migrans) followed by arthritis, usually affecting the knee. Lyme arthritis is a consideration in endemic areas and with a history of tick exposure.
- Indolent infection (e.g., tuberculosis, fungal infections): These can cause chronic inflammatory arthritis, particularly in immunocompromised individuals or those from endemic areas. The presentation can be subtle, with gradual onset of joint pain and swelling, and systemic symptoms like fever and weight loss.
Do Not Miss Diagnoses
- Septic arthritis: Although not typically chronic, if partially treated or in the context of a prosthetic joint, it can present as a chronic condition. It's crucial to consider this diagnosis due to its high morbidity and potential for joint destruction if not promptly treated.
- Hematogenous osteomyelitis or septic bursitis: These conditions can mimic chronic inflammatory arthritis and have significant consequences if missed, including bone or joint destruction.
Rare Diagnoses
- Sarcoidosis: A systemic granulomatous disease that can cause chronic inflammatory arthritis, among other manifestations. It's less common but should be considered, especially with additional symptoms like lung involvement or skin lesions.
- Whipple's disease: A rare, systemic bacterial infection (Tropheryma whipplei) that can cause chronic arthritis, diarrhea, weight loss, and neurological symptoms. It's essential to consider in cases with multisystem involvement and no clear diagnosis.
- Relapsing polychondritis: An autoimmune disease characterized by recurrent episodes of cartilaginous inflammation, which can involve joints and lead to chronic inflammatory arthritis. It's rare but should be considered with specific patterns of cartilage involvement.