What criteria should I use to determine whether to refer a patient with acute pain for specialist evaluation?

Criteria for referral of a patient with acute pain for specialist evaluation include:

• Presence of red flag symptoms such as sudden-onset headache reaching maximum intensity within 5 minutes, new neurological deficits, cognitive dysfunction, personality changes, impaired consciousness, recent head trauma, or headache triggered by cough, Valsalva, or exercise, which warrant urgent assessment and possible referral (CG150) ³.
• Signs suggestive of serious underlying conditions like giant cell arteritis (e.g., scalp tenderness, jaw claudication), acute narrow angle glaucoma, or suspected cancer require prompt referral and further investigations (NG127, CG150) ⁴,³.
• For acute low back pain starting before age 45 and lasting more than 3 months, referral to rheumatology is indicated if 4 or more specific criteria are met, including improvement with movement, nocturnal pain, family history of spondyloarthritis, or associated arthritis or psoriasis (NG65) ².
• Persistent or refractory unilateral facial pain triggered by touching the face (trigeminal neuralgia) should be referred for specialist assessment (NG127) ⁴.
• Rapidly progressive neurological symptoms such as rapidly progressive unsteady gait or sudden-onset difficulty with handwriting without musculoskeletal cause require urgent neurological referral (NG127) ⁴.
• Consider referral when acute pain is disproportionate to any observable injury or when the pain causes significant distress and disability, especially if chronic primary pain is suspected (NG193) ¹.

In summary, referral decisions should be based on the presence of red flag symptoms, neurological signs, suspicion of inflammatory or serious systemic disease, refractory pain syndromes, and significant functional impact.