Differential Diagnosis for 74yo M with LT foot pain and swelling at the 5th digit

• Single most likely diagnosis
  • Gout: The patient has a history of gout and is taking gout prevention medication. The presentation of pain and swelling at the 5th digit, a common location for gouty attacks, makes this the most likely diagnosis. The lack of relief with arthritis cream and the absence of reported injury also point towards gout.
• Other Likely diagnoses
  • Osteoarthritis: Given the patient's age and the location of the pain, osteoarthritis of the 5th metatarsophalangeal joint is a possibility. However, the acute presentation of swelling and the history of gout make this less likely.
  • Bursitis: Inflammation of the bursae around the 5th metatarsophalangeal joint could cause pain and swelling, but the patient's history and lack of relief with topical treatments make this less likely than gout.
  • Tendinitis: Tendinitis of the peroneal tendons, which are located near the 5th digit, could cause pain and swelling in this area. However, the patient denies any history of injury, making this diagnosis less likely.
• Do Not Miss diagnoses
  • Infection (cellulitis or abscess): Although less likely given the patient's presentation and lack of systemic symptoms, an infection in the foot could be serious, especially in older adults or those with compromised immune systems. It's crucial to consider this diagnosis to avoid missing a potentially severe condition.
  • Deep Vein Thrombosis (DVT): While the patient presents with localized symptoms, DVT should be considered, especially if there are any risk factors such as recent immobility, cancer, or history of clotting disorders.
  • Neuroma (Morton's neuroma): Typically presents with pain between the toes, but could potentially cause pain and swelling if large enough. This diagnosis is less likely given the specific location at the 5th digit but should be considered.
• Rare diagnoses
  • Rheumatoid Arthritis: Although less common in older adults without a previous diagnosis, rheumatoid arthritis could present with foot pain and swelling. The patient's lack of systemic symptoms and absence of similar complaints in other joints make this diagnosis rare.
  • Psoriatic Arthritis: Similar to rheumatoid arthritis, this would be an uncommon presentation without a history of psoriasis or other joint involvement.
  • Charcot foot: A rare condition associated with diabetes and neuropathy, characterized by destruction of the foot's bones and joints. Given the patient's age and potential for undiagnosed diabetes, this should be considered, especially if there are signs of neuropathy.