Differential Diagnosis for Unilateral Morning Swelling of Wrist in an 80-Year-Old Man with Autoimmune Disease
Single Most Likely Diagnosis
- Rheumatoid Arthritis (RA) Flare: Given the patient's history of autoimmune disease, a flare of rheumatoid arthritis is highly plausible. RA often presents with symmetric joint involvement, but it can start unilaterally, and morning stiffness is a hallmark symptom.
Other Likely Diagnoses
- Osteoarthritis (OA): Although OA is more commonly associated with afternoon stiffness and is less likely to cause significant morning swelling, it cannot be ruled out, especially in an elderly patient. The unilateral presentation could be due to asymmetric joint degeneration.
- Gout: Gouty arthritis can cause sudden, severe joint pain and swelling, often in a single joint. While it's more common in the big toe, it can affect any joint, including the wrist. The patient's age and autoimmune background might contribute to an increased risk.
- Psoriatic Arthritis (PsA): If the patient has psoriasis or a history suggestive of psoriasis, PsA should be considered. It can cause asymmetric joint involvement and significant morning stiffness.
Do Not Miss Diagnoses
- Septic Arthritis: Although less likely, septic arthritis is a medical emergency that requires prompt diagnosis and treatment. The risk factors for septic arthritis include age, immunocompromised status (due to autoimmune disease or its treatment), and the presence of a single, swollen joint.
- Crystal Arthropathy (Pseudogout): Similar to gout, pseudogout can cause acute, severe joint pain and swelling. It's crucial to distinguish between these conditions due to differences in treatment.
- Lymphoma or Other Malignancies: Certain malignancies can cause joint symptoms, either directly by involving the joint or indirectly through paraneoplastic syndromes. Given the patient's age, it's essential to consider these possibilities, especially if there are other systemic symptoms.
Rare Diagnoses
- Hemochromatosis: This genetic disorder leads to iron overload and can cause arthropathy, among other symptoms. While rare, it's an important consideration in patients with unexplained joint disease.
- Sarcoidosis: Sarcoidosis can cause joint symptoms, including arthritis, and can be associated with autoimmune diseases. It's a rare but important diagnosis to consider, especially if other systemic symptoms are present.
- Relapsing Polychondritis: This rare autoimmune disorder can cause inflammation of cartilaginous structures, including joints, and might present with unilateral wrist swelling in some cases.