In Raynaud's phenomenon, what happens to the nipple when exposed to cold air?

In Raynaud's phenomenon, exposure to cold air triggers a physiological response that leads to vasospasm in the small blood vessels, particularly those in the extremities, including the nipples. This reaction causes the affected area to experience changes in color as blood flow is restricted. Specifically, the nipple may blanch or turn white due to reduced blood supply during a vasospastic episode. As blood flow eventually returns, there can also be a subsequent reddening of the tissue, but the key characteristic during the cold exposure is the blanching effect.

Understanding this response is crucial as it illustrates the underlying pathophysiology of Raynaud's phenomenon, not only in terms of its impact on the nipple but also how similar effects can manifest in other parts of the body. The other options outlined do not accurately depict the physiological changes associated with this condition during cold exposure.