<unk>  originally named familial rectal pain syndrome, is a rare<unk>  whose most notable features are pain in the mandibular, ocular and rectal areas as well as flushing. PEPD often first manifests at the beginning of life, perhaps even in utero, with symptoms persisting throughout life. PEPD symptoms are reminiscent of primary erythromelalgia, as both result in flushing and episodic pain, though pain is typically present in the<unk> ties for primary erythromelalgia. Both of these<unk> s have recently been shown to be allelic, both caused by mutations in the voltage-gated sodium channel NaV1.7 encoded by the gene SCN9A. A different mutation in "SCN9A" causes congenital insensitivity to pain.
Paroxysmal extreme pain disorder
Nociplastic pain
Functional somatic syndrome
Psychogenic pain
Mass psychogenic illness
Syndrome of subjective doubles
Cephalalgiaphobia
Postorgasmic illness syndrome