Focus Article: Steroid Dysregulation and Stomatodynia (Burning Mouth Syndrome)

Stomatodynia (burning mouth syndrome) is characterized by a spontaneous, continuous burning pain felt in the oral mucosa typically of anxiodepressive menopausal women. Because there is no obvious organic cause, it is considered a nonspecific pain. This Focus Article proposes a hypothesis based on the following pathophysiological cascade: chronic anxiety or posttraumatic stress leads to a dysregulation of the adrenal production of steroids. One consequence is a decreased or a modified production of some major precursors for the neuroactive steroid synthesis occurring in the skin, mucosa, and nervous system. At menopause, the drastic fall of the other main precursor supply, the gonadal steroids, leads to a brisk alteration of the production of neuroactive steroids. This results in neurodegenerative alterations of small nerve fibers of the oral mucosa and/or some brain areas involved in oral somatic sensations. These neuropathic changes become irreversible and precipitate the burning pain, dysgeusia, and xerostomia associated with stomatodynia, which all involve thin nerve fibers. Keywords: adrenal steroid, burning mouth syndrome, functional pain, gonadal steroid, idiopathic orofacial pain, neuroactive steroids, neuropathic pain, stomatodynia