[Urticaria and angioedema caused by mastocytosis]. / Urticaire et angioedème des mastocytoses.

Mastocytosis in children are very polymorphic, most often remaining isolated, without an associated visceral lesion. Beside the phenomenon of "urtication" characteristic, papulo-nodular lesions of urticaria and angio-oedema during the mastocytosis are rarely met. In contrast, congestive signs with pruritus, dermographism, congestive erythema and general signs are frequent.

[Role of endothelial activation in urticaria]. / Rôle de l'activation endothéliale dans l'urticaire.

The endothelial cells, because of their privileged situation between the tissues and the vessels, play an important role in the inflammatory reaction. Expression of adhesion molecules (ELAM 1 especially) allows adhesion of circulating neutrophils to the epithelial cell and thus initiates the reaction. During the reactions of immediate hypersensitivity, the flow of leucocytes observed in the late phase is dependent on mastocytes, the recruitment being under the positive or negative influence of several cytokines.

[Histologic signs of cutaneous aging]. / Signes histologiques du vieillissement cutané.

The changes induced by ageing of the skin are particularly visible in photo-exposed areas, indicating the interaction between actinic factors and factors specific to the ageing process itself. The corresponding histological signs affect various structures: epidermis (thinning of the epidermis, reduced cell proliferation...), dermis-epidermis junction (disappearance of the microvilli with defective adhesion of the epidermis to the dermis), dermis (degeneration of elastin and collagen, which is photoinduced, and a moth-eaten appearance with loss of microfibrils as a result of time-related ageing), microcirculation (reduced vascularization, particularly visible in photo-exposed areas...) appendages.

[Chronic urticaria: role of oxatomide]. / Urticaire chronique: place de l'oxatomide.

Oxatomide (Tinset) is a new, powerful, antiallergic agent. Pharmacological and morphological studies have shown that oxatomide is not only an antihistaminic agent but it also inhibits mast cells and basophils degranulation, and neoformed mediators synthesis and release. Open and comparative studies have shown oxatomide to be an effective agent in the treatment of chronic urticaria including physical urticaria and food allergy. All these studies confirm its constant efficacy, giving good to excellent results in 68 to 89 percent of cases. It compares favorably with the classic anti-H1, particularly in that the symptomatic response is much quicker. Moreover the drug is always well tolerated, even when used at higher doses than those presently recommended (30 mg twice daily).