A 34 year-old female presents with episodic blanching of her fingers when exposed to cold. What is the most likely diagnosis?

The clinical presentation of episodic blanching of the fingers in response to cold suggests an ischemic response in the digits, often associated with vasospasm. The most likely diagnosis in this case is Raynaud phenomenon, which is characterized specifically by episodes of reduced blood flow to the extremities, typically triggered by cold or emotional stress.

During these episodes, affected areas may change color, often becoming white (blanching), then blue (cyanosis), and finally red (hyperemia) as circulation returns. This phenomenon reflects an exaggerated vascular response that is common and can occur independently or as secondary to other conditions such as autoimmune diseases.

Other conditions listed, while they may exhibit similar symptoms, do not primarily present with the episodic nature of cold-induced blanching. Sjogren syndrome and systemic lupus erythematosus may have a wide range of symptoms, including skin manifestations, but they do not primarily manifest with isolated episodes of fingertip blanching in response to cold. Scleroderma can involve vasculopathy, but it typically presents with more extensive skin changes and symptoms beyond simple cold-induced vasospasm. Thus, Raynaud phenomenon is the most appropriate diagnosis in this scenario.