What is the likely diagnosis and treatment for a patient with acute onset burning pain at night, involving all joints, described as nerve pain, with improvement upon movement, and no systemic symptoms?

Likely Diagnosis: Peripheral Neuropathy with Nocturnal Neuropathic Pain

This patient's presentation of burning pain affecting multiple joints at night, improving with movement, and described as "nerve pain" is highly characteristic of peripheral neuropathy with neuropathic pain, most likely diabetic peripheral neuropathy. 1, 2

Key Diagnostic Features Present

The clinical presentation contains several hallmark features of neuropathic pain:

• Burning quality of pain is the classic descriptor of neuropathic pain affecting small nerve fibers (C-fibers and Aδ-fibers) 1, 2, 3
• Nocturnal predominance is a pathognomonic feature—pain characteristically worsens at night when external distractions are minimal, allowing abnormal neural signaling to become more noticeable 1, 2
• Improvement with movement distinguishes this from inflammatory arthritis or mechanical joint problems, as neuropathic pain often improves with activity that provides distraction from the aberrant nerve firing 1
• Multi-joint distribution in a symmetric pattern (hips, shoulders, hands, and "hips down") suggests a length-dependent polyneuropathy rather than true articular pathology 2
• Absence of systemic symptoms (no fever, chills) argues strongly against infection, inflammatory arthritis, or malignancy 4

Critical Diagnostic Workup Required

Screen immediately for diabetes mellitus using fasting glucose and HbA1c, as diabetic neuropathy is the most common cause of this presentation 1, 2, 3. Up to 50% of diabetic peripheral neuropathy may be initially asymptomatic, but when symptomatic, patients describe exactly this pattern of burning pain 2.

Additional essential screening includes:

• Vitamin B12 level (deficiency causes identical symptoms) 3
• Thyroid function tests (hypothyroidism-associated neuropathy) 2
• Complete metabolic panel (renal dysfunction, electrolyte abnormalities) 2
• Lipid panel (dyslipidemia contributes to neuropathy) 2

Physical examination must specifically assess:

• Small fiber function: pinprick and temperature sensation 2, 3
• Large fiber function: vibration perception using 128-Hz tuning fork, position sense, and reflexes 2, 3
• Protective sensation in feet 2
• Pedal pulses and ankle-brachial index to exclude peripheral arterial disease 2

Treatment Algorithm

First-Line Pharmacological Management

Initiate treatment with one of three first-line agents (all have equivalent efficacy with 38% of patients achieving ≥50% pain reduction at optimal dosing) 1, 2:

1. Duloxetine 30 mg daily, titrate to 60 mg daily after one week 2, 3
2. Pregabalin 75 mg twice daily, titrate up to 150-300 mg twice daily as tolerated 1, 2
3. Gabapentin 300 mg daily, titrate up to 900-1800 mg three times daily as tolerated 1, 2

Start at lower doses with slower titration in older patients to minimize adverse effects (sedation, dizziness, peripheral edema) 1.

Address Underlying Etiology Aggressively

If diabetes is confirmed:

• Target HbA1c <7% (individualized based on patient factors) to slow neuropathy progression 2, 3
• Optimize blood pressure and lipids as these directly influence neuropathy progression 1, 2
• Weight management if metabolic syndrome is present 1

Non-Pharmacological Interventions

Recommend regular physical activity and aerobic exercise as this has protective effects on neuropathy progression and improves pain outcomes 1, 2. Supervised exercise therapy specifically improves pain-free function 2.

Psychological Comorbidity Screening

Screen for depression and anxiety at initial visit and follow-up, as over two-thirds of patients with painful neuropathy develop these comorbidities, and addressing psychological factors significantly improves overall pain outcomes 1, 2, 3.

Common Pitfalls to Avoid

Do not dismiss nocturnal symptoms as insignificant—they represent a classic diagnostic feature requiring treatment, not a minor complaint 1.

Do not misdiagnose as inflammatory arthritis based on multi-joint involvement. The absence of daytime pain, morning stiffness, joint swelling, or systemic symptoms argues strongly against rheumatologic disease 4.

Avoid recommending prolonged cold water immersion or ice application for symptom relief, as this can lead to immersion foot, skin ulceration, and infection risk in patients with neuropathy 2, 5.

Do not order extensive imaging initially. Standard nerve conduction studies may be completely normal in small fiber neuropathy, as these tests only evaluate large myelinated fibers 2. Imaging is not indicated unless red flags for systemic disease are present 4.

Monitor medication response objectively with pain scales at follow-up visits to ensure desired pain reduction and avoid adverse effects 3.