[Urticaria and mastocytosis: As common as we think?].

Urticaria y mastocitosis: ¿tan frecuente como pensamos? To t he Edit or: In daily practice and in the classical text books of dermatology, urticaria is considered to be a common manifestation of mastocytosis; along the same lines, mastocytosis is considered a cause of both acute and chronic urticaria. Nevertheless, a literature review reveals no data to support any such association. A comprehensive review carried out using Pubmed and the Spanish Medical Index (IME, Índice Médico Español) (keywords: mastocytosis, telangiectasia macularis eruptiva perstans, urticaria, Darier, dermographism) yielded no data on the relative risk of urticaria in patients with cutaneous mastocytosis and few data on patients with acute or chronic urticaria caused by an underlying mastocytosis. The only paper to directly mention an association between the 2 conditions was published by Martín-Muñoz, 6 who reported the case of a 5-year-old boy with a 1-year history of chronic urticaria. A skin biopsy revealed mastocytosis of the urticaria pigmentosa type. All other tests (tryptase and histamine) were normal, except for a positive skin prick test for olive pollen. Figure 1 Telangiectasias on healthy skin at the neckline. Figure 2 Wheal-like plaque on the right arm after applying an ice cube. It is believed that testing for Darier sign could trigger urticaria-like symptoms and possibly even anaphylactic shock in patients with mastocytosis. However, a retrospective study on the causes of anaphylaxis in 601 patients found no patients with a history of mastocytosis. 7 Darier sign is considered a dermographism typical of mastocytosis, and the 2 conditions have a common pathogenesis consisting of mechanical activation of the inflammatory cascade that triggers the appearance of wheals 8 ; this may confirm the relationship between urticaria and mastocytosis. We present the case of a 42-year-old man who consulted for the appearance of wheals in exposed areas (particularly, on the face and hands) when he was outdoors in cold weather, when he touched cold containers, or when he was exposed to hot or cold water. The patient also reported pharyngeal itching whenever he drank cold beverages (whether water or another type of refreshment). Physical examination revealed telangiectasias on the upper thorax and back, as well as the shoulders (Figure 1). Challenge tests with an ice cube (Figure 2) and with cold water (Figure 3) were positive, with the formation of wheals, whereas tests with hot water, heat, and light were negative, as were the exercise test, dermographism test, and …