Differential Diagnosis
- Single most likely diagnosis
- Giant Cell Arteritis (GCA): The patient's age, symptoms of worsening soreness in the upper body, high inflammatory markers (Sed rate 125, CRP 233), and worsening cognition are consistent with GCA, particularly given the elevated platelet count which is often seen in this condition. The presence of anorexia, weight loss, and fatigue further supports this diagnosis.
- Other Likely diagnoses
- Polymyalgia Rheumatica (PMR): Similar to GCA, PMR is characterized by muscle pain and stiffness, particularly in the upper body, and is often associated with elevated inflammatory markers. However, the absence of jaw claudication or visual symptoms makes GCA slightly more likely.
- Rheumatoid Arthritis (RA): Although less likely given the patient's age and the acute onset, RA could present with similar symptoms of soreness, fatigue, and elevated inflammatory markers. The normal aldolase level does not strongly support an active muscle disease like polymyositis, which can be associated with RA.
- Malignancy: The combination of weight loss, anorexia, and elevated inflammatory markers could suggest an underlying malignancy, which would need to be ruled out with further investigation.
- Do Not Miss (ddxs that may not be likely, but would be deadly if missed.)
- Temporal Arteritis with impending visual loss: A variant of GCA, it is crucial to promptly diagnose and treat to prevent blindness.
- Infection (e.g., endocarditis, abscess): Although less likely given the clinical presentation, infections can cause elevated inflammatory markers and must be considered, especially in elderly patients who may not present with typical symptoms.
- Vasculitis (other forms): Other types of vasculitis, such as ANCA-associated vasculitis, could present similarly and have significant morbidity if not promptly treated.
- Rare diagnoses
- Relapsing Polychondritis: An autoimmune disorder that could cause inflammation and symptoms similar to those presented, although it is much rarer and would be less likely without specific symptoms like cartilage involvement.
- Eosinophilic Granulomatosis with Polyangiitis (Churg-Strauss Syndrome): A rare form of vasculitis that could present with a wide range of symptoms including muscle pain and elevated inflammatory markers, but is typically associated with asthma and eosinophilia, which are not mentioned here.