Differential Diagnosis for 60-year-old Female with Proximal Weakness and Systemic Symptoms
Single Most Likely Diagnosis
- Polymyalgia Rheumatica (PMR): This condition is characterized by proximal muscle weakness, stiffness, and pain, often accompanied by systemic symptoms like fatigue, headaches, and subjective fevers. The age of the patient and the distribution of symptoms make PMR a strong consideration.
Other Likely Diagnoses
- Rheumatoid Arthritis (RA): While RA typically presents with joint pain and swelling, some patients may experience proximal muscle weakness and systemic symptoms similar to those described.
- Lupus: Systemic Lupus Erythematosus can present with a wide range of symptoms, including proximal muscle weakness, fatigue, headaches, and fever, making it a plausible diagnosis.
- Hypothyroidism: Muscle weakness, fatigue, and aches can be symptoms of hypothyroidism, which is common in older adults and could explain some of the patient's symptoms.
Do Not Miss Diagnoses
- Giant Cell Arteritis (GCA): Although less common, GCA is a serious condition that can lead to blindness and other severe complications if not promptly treated. It often co-exists with PMR and can present with similar systemic symptoms.
- Infections (e.g., Endocarditis, Osteomyelitis): Certain infections can cause systemic symptoms like fever, chills, and fatigue, along with localized pain. Missing these diagnoses could be catastrophic.
- Malignancy (e.g., Lymphoma, Multiple Myeloma): Some cancers can present with systemic symptoms and muscle weakness. Although less likely, these diagnoses are critical not to miss due to their severe implications.
Rare Diagnoses
- Dermatomyositis: An inflammatory muscle disease characterized by skin rash and muscle weakness. It's less common but should be considered in the differential due to the presence of proximal weakness.
- Inclusion Body Myositis: A progressive muscle disease that could explain the proximal weakness but is less likely due to its rarity and slower progression.
- Vasculitis (e.g., Polyarteritis Nodosa): A group of diseases characterized by inflammation of the blood vessels, which can present with a wide range of symptoms including muscle weakness and systemic symptoms, but are relatively rare.