Olfactory dysfunction and autoimmunity: pathogenesis and new insights.

Olfaction plays an important role in the perception of our environment. Smell impairment is known to be a manifestation of several autoimmune diseases. Similarities between the olfactory and immune systems and previously published human studies and animal models of autoimmune diseases account for the accumulating evidence for this observation. In this review, we will present the current literature concerning olfactory dysfunction in autoimmune diseases, discuss clinical aspects and provide new insights regarding pathogenesis and possible mechanisms.