Transient Symmetric Blanching Macules on a Background of Reticulate Erythema

An 11-year-old girl was referred to the dermatology clinic for evaluation of a rash on the legs and feet of 1 year's duration.The rash appeared every time she was standing for longer than 10 to 15 minutes and resolved when sitting or laying down.After the initial onset, the rash did not spread to other body areas but became more prominent in appearance.The patient endorsed intense pruritus associated with the rash.A review of systems was negative for fever, headaches, history of blood clots, and joint pain.She did not have any known medical conditions or take any medications.The patient's mother reported that the patient experienced episodes of leg numbness while sitting in vehicles from 6 to 10 years of age.There was no family history of rheumatologic, hematologic, or cardiac conditions.The patient's mother had experienced 2 miscarriages but denied any other obstetric complications.The patient had 1 sibling who was unaffected.Physical examination revealed reticulate erythema on the calves with scattered regions of blanching and evanescent pink macules as well as dermatographism.One month prior to presenting to dermatology, the patient was evaluated by rheumatology, endocrinology, and hematology.Laboratory workup completed at age 3 years included antinuclear antibody, anticardiolipin antibody, and antithrombin III activity; factor V Leiden; cryoglobulins; quantitation (human chorionic gonadotropin); proteins S and C activity; antineutrophil cytoplasmic antibody screen; thyroid studies; prothrombin time; and partial thromboplastin time.All laboratory results were within reference range. WHAT'S YOUR DIAGNOSIS?a. BASCULE syndrome b.Bier spots c.