Chronic urticaria is usually associated with fibromyalgia syndrome.

Although the pathophysiology of chronic urticaria is not fully understood, it is possible that dysfunctioning of peripheral cutaneous nerve fibres may be involved. It has also been suggested that fibromyalgia syndrome, a multi-symptomatic chronic pain condition, may be associated with alterations and dysfunctioning of peripheral cutaneous nerve fibres. The aim of this study was to determine whether patients with chronic urticaria are also affected by fibromyalgia syndrome. A total of 126 patients with chronic urticaria were investigated for fibromyalgia syndrome. An unexpectedly high proportion (over 70%) had fibromyalgia syndrome. The corresponding proportion for 50 control dermatological patients was 16%, which is higher than previously published data for the Italian general population (2.2%). It is possible that dysfunctional cutaneous nerve fibres of patients with fibromyalgia syndrome may release neuropeptides, which, in turn, may induce dermal microvessel dilatation and plasma extravasation. Furthermore, some neuropeptides may favour mast cell degranulation, which stimulates nerve endings, thus providing positive feedback. Chronic urticaria may thus be viewed in many patients, as a consequence of fibromyalgia syndrome; in fact, skin neuropathy (fibromyalgia syndrome) may trigger neurogenic skin inflammation (chronic urticaria).