Patient attended their GP with elbow and proximal forearm swelling, moderate pain, and restricted extension. He recalls having a small scratch on the elbow skin several days ago.

Lab results:

• white cell count: 11.53
  • neutrophils: 8.57 (74.3%)
  • lymphocytes: 1.98 (17.2 %)
• ESR: 10
• CRP: 58.6.

The differential diagnosis includes cellulitis, osteomyelitis, septic arthritis, and olecranon bursitis. Examination, ultrasound, and x-ray findings are in keeping with uncomplicated cellulitis. Initial treatment is with antibiotics, elevation, and monitoring erythema for improvement.