Unusual urticarias

Disorders characterized by predominant or exclusive dermal inflammation

Some cutaneous inflammatory disorders are typified by a predominant or exclusive localization in the dermis. They can be further subdivided by the principal cell types into lymphocytic, neutrophilic, and eosinophilic infiltrates, and mixtures of them are also seen in a proportion of cases. This review considers such conditions. Included among the lymphoid lesions are viral exanthems, pigmented purpuras, gyrate erythemas, polymorphous light eruption, lupus tumidus, and cutaneous lymphoid hyperplasia. Neutrophilic infiltrates are represented by infections, Sweet syndrome, pyoderma gangrenosum, and hidradenitis suppurativa, as well as a group of so-called "autoinflammatory" dermatitides comprising polymorphonuclear leukocytes. Eosinophil-dominated lesions include arthropod bite reactions, cutaneous parasitic infestations, the urticarial phase of bullous pemphigoid, Wells syndrome (eosinophilic cellulitis), hypereosinophilic syndrome, and Churg-Strauss disease. In other conditions, eosinophils are admixed with neutrophils in the corium, with or without small-vessel vasculitis. Exemplary disorders with those patterns include drug eruptions, chronic idiopathic urticaria, urticarial vasculitis, granuloma faciale, and Schnitzler syndrome (chronic urticarial with a monoclonal gammopathy).

Anatomy and neurophysiology of pruritus

Itch has been described for many years as an unpleasant sensation that evokes the urgent desire to scratch. Studies of the neurobiology, neurophysiology, and cellular biology of itch have gradually been clarifying the mechanism of itch both peripherally and centrally. The discussion has been focused on which nerves and neuroreceptors play major roles in itch induction. The "intensity theory" hypothesizes that signal transduction on the same nerves leads to either pain (high intensity) or itch (low intensity), depending on the signal intensity. The "labeled-line coding theory" hypothesizes the complete separation of pain and itch pathways. Itch sensitization must also be considered in discussions of itch. This review highlights anatomical and functional properties of itch pathways and their relation to understanding itch perception and pruritic diseases.

The definition and diagnostic testing of physical and cholinergic urticarias--EAACI/GA2LEN/EDF/UNEV consensus panel recommendations

The recommendations for the definition and diagnosis presented in this position paper are the result of a panel consensus meeting held in December 2008 in Berlin. This consensus meeting was a joint initiative of EAACI (European Academy of Allergology and Clinical Immunology) Dermatology Section, the EU-funded network of excellence, GA(2)LEN (Global Allergy and Asthma European Network), the EDF (European Dermatology Forum) and UNEV (urticaria network e.V.). The aim of these recommendations is to improve the diagnosis and management of patients with physical urticaria or cholinergic urticaria and to promote research and a better understanding of these diseases. Our recommendations used the paper produced by a 1996 expert meeting (1) and they acknowledge the latest changes in our understanding of physical urticarias and cholinergic urticaria as well as the recent development of novel diagnostic tools. In addition, this consensus paper highlights areas of need for further research.

Muckle-Wells syndrome: report of six cases with hyperpigmented sclerodermoid skin lesions

Muckle-Wells syndrome (MWS) is a rare syndrome, characterized by chronic recurrent urticaria, often combined with fever, chills, rigors, malaise, and arthralgia. Progressive sensorineural deafness, and, in approximately one third of the patients, amyloidosis of the kidneys as well as of other organs may occur. It was first described in 1962 by Muckle and Wells. Herein we describe six cases of MWS showing, in addition to the classic features of MWS, unique skin lesions that to the best of our knowledge have not been described before in association with MWS.

A comprehensive review of physical urticaria

Physical urticarias are an intriguing subgroup of urticarial disorders with unique circumstances and trigger stimuli precipitating symptom development. A thorough understanding of the pathophysiology will assist in the management process by facilitating prompt recognition and more accurate diagnoses.

Late-phase urticaria Update

In ordinary urticaria, individual lesions disappear within 24 hours. However, we sometimes encounter patients whose eruptions last longer than 24 hours, but without evidence of vasculitis or a history of exposure to pressure. In these patients, histology reveals a perivascular infiltration, predominantly of eosinophils, depending on the timing of the biopsy. Unlike urticarial vasculitis, no immunoglobulins, complement deposition, or endothelial fibrinoid degeneration is observed. The peripheral eosinophil counts and serum complement levels appear within normal range. No protein urea or joint pain is observed, and the lesions can be controlled only by systemic glucocorticoids. We recognize such a urticarial reaction as a different clinical entity than usual urticaria, which is presumably mediated by late-phase inflammatory reaction in immediate hypersensitivity.