Differential diagnosis includes trauma, septic and reactive arthritis
The differential diagnosis of acute gouty arthritis includes trauma, pseudogout (arthritis involving calcium pyrophosphate dehydrate), septic arthritis, reactive arthritis, post-streptococcal arthritis, and Lyme disease.
Trauma with a resulting acute or stress fracture can be determined by x-ray or magnetic resonance imaging (MRI).
Pseudogout requires aspiration of fluid and examination for calcium pyrophosphate crystals under polarizing microscopy.9
Septic arthritis may present in a similar manner to other causes of acute arthritis. Therefore, arthrocentesis is needed to identify the causative infectious agent.10 Septic arthritis was considered in our patient, given his age, history of diabetes mellitus, and finding of skin ulceration over the toe. However, our patient did not have systemic symptoms, and the joint aspiration did not show the presence of bacteria.
Reactive arthritis typically presents with inflammation of the ligaments and tendons at their sites of insertion into the bone, and can affect other areas of the body, such as the genitourinary and ocular systems.11
Post-streptococcal arthritis (aka acute rheumatic fever [ARF]) and Lyme disease can also present with joint complaints. The arthritis in ARF is usually migratory and involves several joints. Fever, rash, and a history of group A streptococcal infection are also diagnostic features.12 History of travel to an endemic area or seasonal exposure would further differentiate Lyme disease from other causes of arthritis.
Deciding on a course of treatment
Initial treatment choices for acute gout include nonsteroidal anti-inflammatory drugs (NSAIDs), colchicine, and corticosteroids.13 Various NSAIDs have been studied in the treatment of acute gout, but none showed absolute superiority over others. One option is naproxen 500 mg twice daily, but the choice of NSAID is mainly based on the adverse reaction profile and the physician’s preference.