What is the appropriate management for a patient with leukocytosis (elevated White Blood Cell (WBC) count) and neutrophilia (elevated absolute neutrophils) presenting with wrist pain?

Management of Elevated WBC and Neutrophils with Wrist Pain

Immediately obtain wrist radiographs and a complete blood count with manual differential to rule out septic arthritis, which is the most critical diagnosis to exclude given the combination of leukocytosis and joint pain. 1, 2

Initial Diagnostic Workup

Laboratory Assessment

• Order CBC with manual differential immediately to characterize the leukocytosis and calculate absolute neutrophil counts 2, 3
• Review peripheral blood smear to assess for left shift (≥16% band neutrophils), which has a likelihood ratio of 4.7 for bacterial infection even with normal total WBC 2, 3
• An absolute band count ≥1,500 cells/mm³ has the highest likelihood ratio (14.5) for detecting bacterial infection and warrants aggressive evaluation for septic arthritis 1, 2
• Neutrophil percentage >90% has a likelihood ratio of 7.5 for bacterial infection 2, 3
• Total WBC ≥14,000 cells/mm³ has a likelihood ratio of 3.7 for bacterial infection 1

Imaging Protocol

• Obtain wrist radiographs as the first-line imaging study for all patients with chronic wrist pain 1
• If radiographs are normal or equivocal and infection is suspected, proceed with MRI without IV contrast to evaluate for early septic arthritis, osteomyelitis, or soft tissue infection 1

Critical Rule-Out: Septic Arthritis

Patients with suspected wrist infection should undergo arthrocentesis (joint aspiration) immediately before initiating antibiotics 1. The combination of leukocytosis with neutrophilia and joint pain raises significant concern for bacterial infection.

Indications for Urgent Arthrocentesis

• Wrist pain with systemic leukocytosis and neutrophilia 1
• Any clinical signs of joint inflammation (warmth, erythema, swelling, limited range of motion) 1
• Fever accompanying wrist pain, even if low-grade 1

Synovial Fluid Analysis

• Joint aspiration fluid typically shows marked leukocytosis with neutrophilic predominance in septic arthritis 1
• Send fluid for cell count with differential, Gram stain, and bacterial culture 1

Differential Diagnosis Based on Clinical Context

If Infection is Confirmed or Highly Suspected

• Obtain blood cultures before starting antibiotics if systemic symptoms or sepsis signs are present 2, 3
• Initiate empiric broad-spectrum antibiotics immediately after obtaining cultures if septic arthritis is suspected 1
• Leukocytosis without fever does not exclude infection, particularly in older adults 1, 2

If Inflammatory Arthritis is Suspected

Adult-Onset Still's Disease (AOSD) should be considered when wrist arthritis presents with marked leukocytosis and neutrophilia 1:

• The wrist is involved in 73% of AOSD cases, making it one of the most commonly affected joints 1
• Leukocytosis in AOSD is striking, with 50% of patients having WBC >15,000 cells/μL and 37% having WBC >20,000 cells/μL 1
• Look for associated fever (often spiking pattern), salmon-pink rash, sore throat, lymphadenopathy, and hepatosplenomegaly 1
• Check ESR, CRP, and ferritin levels, which are typically markedly elevated 1
• Carpal and pericapitate abnormalities develop after 6 months of disease onset with progressive joint space narrowing 1

If Radiographs Show Fracture or Bone Abnormality

• For suspected radiographically occult fractures or stress fractures, either MRI or CT without contrast is appropriate 1
• For patients with prior scaphoid fractures and chronic pain, obtain either CT or MRI without IV contrast to evaluate for nonunion, malunion, or osteonecrosis 1

If No Infection or Inflammatory Process Identified

Consider non-infectious causes of wrist pain with incidental leukocytosis 4, 5:

• De Quervain tenosynovitis (positive Finkelstein test, negative grind test) 4
• Carpal tunnel syndrome (requires clinical evaluation with electrophysiologic studies) 1, 6
• Ulnar neuropathy (sensory changes in 4th and 5th digits) 4

Common Pitfalls to Avoid

• Do not overlook the significance of left shift even when total WBC is only mildly elevated, as a left shift can indicate serious bacterial infection with normal WBC count 2, 3
• Do not treat asymptomatic patients with antibiotics based solely on mildly elevated WBC counts without identifying a clear infectious source 2, 3
• Do not delay arthrocentesis if septic arthritis is suspected, as early diagnosis and treatment are critical to prevent joint destruction 1
• Do not assume leukocytosis is reactive without thorough evaluation, particularly when accompanied by localized joint symptoms 1, 7

When to Obtain Additional Studies

• If radiographs are normal or equivocal with persistent symptoms and unclear diagnosis, MRI without IV contrast is appropriate 1
• For suspected inflammatory arthritis requiring management guidance, MRI with or without IV contrast is appropriate 1
• Comprehensive metabolic panel should be ordered to monitor for tumor lysis syndrome if malignancy is suspected based on extreme leukocytosis or other concerning features 2, 3