Clinical observation is the most appropriate next step in management. This patient's presentation is suggestive of primary Raynaud phenomenon, a common occurrence in young women that may be seen in up to 30% of women who are white. Raynaud phenomenon may also be the initial symptom of an underlying fibrosing connective tissue disease (CTD) such as mixed connective tissue disease or systemic sclerosis; the predictors/features include severe and prolonged episodes of vasospasm, asymmetric involvement of the digits, and abnormal nailfold capillary examination and/or digital pitting. This patient has none of these features, has a negative family history for CTD, and has undergone nailfold capillary examination, which is normal. She is at a low risk for progressing to a CTD, should be reassured, and can be followed periodically. In these patients, most episodes of Raynaud phenomenon are self-limiting and do not require treatment. Persistently symptomatic patients can be treated with a peripherally acting calcium channel blocker such as nifedipine or amlodipine. Sildenafil and endothelin-1 blockers can be used in refractory cases.

This patient's likelihood of developing a CTD is low, and measuring antinuclear and anti-U1-ribonucleoprotein antibodies would be of extremely low yield and would not be cost-effective.

Similarly, obtaining an antiphospholipid antibody panel and cryoglobulins in a patient who has no history or evidence of thrombosis, pregnancy loss, or vasculitis is unnecessary and not cost-effective.

Digital arteriography is an invasive test and is usually normal in patients with Raynaud phenomenon. Obtaining this study would be appropriate if thromboangiitis obliterans (“Buerger disease”) were suspected, which is a nonatherosclerotic vascular inflammatory disease affecting the medium and small vessels of the extremities and digits that has a strong association with smoking and male gender.