Reactive arthritis triad components include which features?

• A. Conjunctivitis; Urethritis; Oligoarthritis
• B. Conjunctivitis; Fever; Myalgia
• C. Urticaria; Erythema; Arthralgia
• D. Osteoarthritis; Tendinopathy; Myositis

Answer: (A)

Reactive arthritis is an inflammatory arthritis that often follows an infection elsewhere in the body. The hallmark pattern is a triad of conjunctivitis (eye inflammation), urethritis (urinary-tract–type symptoms), and arthritis that is typically asymmetric and involves only a few joints, usually in the lower limbs (oligoarthritis). This combination—eye involvement, urinary symptoms, and joint inflammation—captures the classic presentation of reactive arthritis and is the best fit for the question.

Understanding helps: the arthritis is usually sterile and can be accompanied by enthesitis or mucocutaneous signs, reflecting its spondyloarthropathy-like nature. Other symptoms like fever with myalgia, urticaria/erythema, or degenerative patterns like osteoarthritis and noninflammatory forms like tendinopathy or myositis do not define this triad and thus are not the characteristic cluster seen in reactive arthritis.