Urticaria is a common mast cell‐driven disease which is characterized by red, itchy swellings. Urticaria, that persists more than 6 weeks in a repetitive manner (each lesion disappearing in <24 h), is called chronic urticaria. Chronic urticaria can be either spontaneous without the need of a trigger, or inducible in which with a known trigger the lesions can be provoked. Chronic inducible urticarias include the physical urticarias and some other forms such as cholinergic urticaria.
Part of the book: Urticaria and Angioedema
Dermatitis herpetiformis is an autoimmune skin disease, which is strongly related to coeliac disease. Moreover, some authors accept it as the skin manifestation of coeliac disease. It is a chronic, recurrent disease with polymorphic skin eruptions and pruritus. Dermatitis herpetiformis is a disease of the young adults mostly, but can be seen at any age. It is characterized by papules, vesicles, excoriations, and urticarial plaques clinically. Histopathological examination reveals subepidermal separation, and with this finding, it needs to be differentiated from linear IgA bullous dermatitis and bullous pemphigoid. In this case, direct immunofluorescence is helpful. Granular deposition of IgA is pathognomonic for dermatitis herpetiformis. Dermatitis herpetiformis can accompany other autoimmune disorders such as type I diabetes mellitus, thyroid diseases, vitiligo, and collagen tissue diseases. Dermatitis herpetiformis is, usually, successfully treated with dapsone and gluten-free diet.
Part of the book: Autoimmune Bullous Diseases