A 70-year-old woman with a history of rheumatoid arthritis complains of increasing pain and stiffness in her hands, especially at the base of her thumbs. The pain is worse with use, such as when opening jars or turning keys. What is the likely cause and the treatment?
This is likely symptomatic osteoarthritis of the thumb (also called thumb base arthritis or trapeziometacarpal arthritis), which is common in older adults, especially in those with a history of other forms of arthritis like rheumatoid arthritis. Conservative management would be first-line, with options including thumb spica splinting, activity modifications, and NSAIDs for pain relief. If these measures are unsuccessful, intra-articular corticosteroid injections could be considered. Severe cases may require surgical intervention, such as arthroplasty or fusion.