BASCULE syndrome (Bier anemic spots and cyanosis with an urticaria-like eruption) is a vasomotor eruption that is characterized by asymptomatic irregular white macules on a cyanotic background (Bier anemic spots) that appear after a few minutes of immobile standing, followed by the appearance of pruritic, orange-red papules superimposed on the white macules. The lesions are distributed on the legs and may also be seen on the arms or, rarely, on the trunk. They resolve with sitting, walking, or moving the affected limbs.

Both children and adults have been reported to be affected by BASCULE syndrome, although it is more common in younger adolescents. While males and females are affected, there appears to be a slight female predominance. The anemic spots are most likely caused by venous pooling from standing or orthostatism, leading to an exaggerated vasoconstrictive response of the microvasculature. The subsequent pruritic papules may be a paradoxical urticaria reaction or secondary to mast cell degranulation from local hypoxia; however, the exact mechanism is unknown.

Although uncommon, affected individuals may also have postural orthostatic tachycardia syndrome (POTS) as well as ECG abnormalities (eg, atrioventricular [AV] block, atrial fibrillation [AFib], sinus tachycardia).