What saying or mnemonic is associated with reactive arthritis that describes its classic triad of conjunctivitis, urethritis, and asymmetric arthritis of the lower limbs?

The Classic Saying for Reactive Arthritis

The classic saying associated with reactive arthritis is "Can't see, can't pee, can't climb a tree," which describes the triad of conjunctivitis (can't see), urethritis (can't pee), and arthritis affecting the lower limbs (can't climb a tree) 1, 2, 3.

Understanding the Mnemonic

This memorable phrase captures the three cardinal features of reactive arthritis, though it's critical to understand that most patients do not present with the complete triad 2, 4. The saying refers to:

• "Can't see" = Conjunctivitis or uveitis (ocular inflammation)
• "Can't pee" = Urethritis (urogenital symptoms including urethral discharge or dysuria)
• "Can't climb a tree" = Asymmetric oligoarthritis, typically affecting large joints of the lower extremities (knees, ankles)

Clinical Reality vs. The Classic Triad

Important caveat: While this triad is taught as the hallmark of reactive arthritis, only about half of clinicians correctly recognize that the complete triad is NOT required for diagnosis 4. In fact, the majority of patients do not present with all three features simultaneously 2.

Additional Manifestations to Recognize

Beyond the classic triad, watch for:

• Enthesitis (inflammation at tendon/ligament insertions)
• Dactylitis (sausage digits)
• Keratoderma blennorrhagicum (pustular skin lesions on palms/soles)
• Circinate balanitis (painless penile lesions)
• Oral ulcers
• Sacroiliitis or axial involvement 5, 6, 7, 3

Triggering Infections

Reactive arthritis develops 1-4 weeks after:

• Genitourinary infections: Chlamydia trachomatis, Ureaplasma urealyticum, Neisseria gonorrhoeae
• Gastrointestinal infections: Salmonella, Shigella, Yersinia, Campylobacter 1, 2, 8

Diagnostic Approach

When you suspect reactive arthritis based on the clinical presentation:

1. Confirm preceding infection (history of diarrhea or urethritis 1-4 weeks prior)
2. Document asymmetric oligoarthritis (typically lower extremity large joints)
3. Check for HLA-B27 (positive in 60-80% of cases, though not required for diagnosis)
4. Rule out septic arthritis with joint aspiration if monoarticular
5. Screen for STIs if genitourinary symptoms present 9, 1

No single test is specific for reactive arthritis 4—diagnosis relies on the clinical pattern of post-infectious asymmetric arthritis with or without extra-articular features.