Differential Diagnosis for a 38-year-old Woman with Low-grade Fever and Symmetrical Joint Pain
Single Most Likely Diagnosis
- Rheumatoid Arthritis (RA): This is a common autoimmune disorder characterized by symmetrical joint pain and inflammation, often accompanied by low-grade fever and fatigue. The patient's symptoms of symmetrical joint pain involving fingers, wrists, and knees are classic for RA.
Other Likely Diagnoses
- Systemic Lupus Erythematosus (SLE): An autoimmune disease that can present with joint pain, fever, and fatigue, among other symptoms. The symmetrical nature of the joint pain could suggest SLE, although it typically involves more systemic symptoms.
- Viral Arthritis: Certain viral infections can cause arthritis that may present similarly to RA or SLE, with joint pain and low-grade fever. The recent onset and the presence of fatigue could suggest a viral etiology.
- Reactive Arthritis: This form of arthritis occurs as a reaction to an infection elsewhere in the body, often in the gastrointestinal tract or the urethra. It can present with joint pain and fever, although it typically does not have a symmetrical pattern.
Do Not Miss Diagnoses
- Septic Arthritis: Although less likely given the symmetrical nature of the joint pain, septic arthritis is a medical emergency that requires prompt diagnosis and treatment. It can present with fever and joint pain, and any delay in diagnosis can lead to severe joint damage.
- Lyme Disease: Caused by the bacterium Borrelia burgdorferi, Lyme disease can present with fever, fatigue, and joint pain, particularly in endemic areas. It's crucial to consider this diagnosis to avoid missing a treatable cause of arthritis.
- Endocarditis: Infective endocarditis can present with fever, fatigue, and joint pain due to immune complex deposition. Although less common, it is a life-threatening condition that must not be missed.
Rare Diagnoses
- Relapsing Polychondritis: A rare autoimmune disorder characterized by recurrent episodes of cartilage inflammation, which can involve joints and lead to fever and fatigue.
- Sjögren's Syndrome: An autoimmune disorder that primarily affects the glands that produce tears and saliva but can also cause joint pain and fever.
- Mixed Connective Tissue Disease (MCTD): A rare autoimmune disorder that combines features of lupus, scleroderma, and rheumatoid arthritis, and can present with joint pain, fever, and fatigue.