Differential Diagnosis
- Single most likely diagnosis
- Dermatomyositis: The patient's symptoms of fatigue, generalized weakness, and difficulty performing daily activities, combined with the photograph of the hands (likely showing Gottron's sign, a characteristic rash of dermatomyositis), point towards this diagnosis. Muscle strength is also reduced, which is consistent with dermatomyositis. Further evaluation would likely show muscle inflammation (E), which is a hallmark of this condition.
- Other Likely diagnoses
- Polymyositis: Similar to dermatomyositis, but without the characteristic skin rash. The patient's symptoms of muscle weakness and reduced muscle strength could also be consistent with polymyositis.
- Inclusion body myositis: This condition is characterized by intramuscular inclusion bodies (B) and progressive muscle weakness, particularly in the arms and legs.
- Do Not Miss (ddxs that may not be likely, but would be deadly if missed.)
- Metastatic spinal cord compression (D): Although the patient has no history of serious illness, it is essential to consider this possibility, as it can cause progressive muscle weakness and would require urgent attention.
- Leukocytoclastic vasculitis (C): This condition can cause muscle weakness and skin rash, although it is less likely than dermatomyositis or polymyositis.
- Rare diagnoses
- Epidermal hyperplasia (A): This is not typically associated with muscle weakness and is more commonly seen in conditions such as psoriasis.
- Peripheral nerve demyelination (F): This condition, such as Guillain-Barré syndrome, can cause muscle weakness, but the patient's symptoms and lack of other neurological signs make it less likely.