Conversion to Paradoxical Finding on Technetium-99m-labeled RBC Scintigraphy after Treatment for Secondary Raynaud's Phenomenon.

An 18-year-old woman reported that after exposure to cold temperatures her fingers appeared blue and her hands and feet felt cold. Secondary Raynaud's phenomenon (RP) associated with peripheral vascular disease was suspected. Technetium (Tc)-99m-labeled RBC hand scintigraphy after cold change showed decreased blood pool activity in her fingers. The patient's symptoms improved after she received sarpogrelate HCL (200 mg/day) and nifedifine (40 mg/day). Follow-up scintigraphy performed 7 months after the patient started treatment showed paradoxically increased blood pool activity in her fingers after cold challenge. To the best of our knowledge, this is the first case report of a patient with secondary RP showing paradoxical change on scintigraphy after she received medication that improved her symptoms.