Clinical dermatology • Concise report CED Clinical and Experimental Dermatology Localized salt-dependent aquagenic urticaria: a subtype of aquagenic urticaria? R. Gallo, 1 M. Gonc ßalo, 2 E. Cinotti, 1 F. Cecchi 1 and A. Parodi 1 1 Department of Health Sciences (Di.S.Sal), Section of Dermatology, University of Genoa, Genoa, Italy; and 2 Dermatology Clinic of Dermatology, Faculty of Medicine and University Hospital of Coimbra, Coimbra, Portugal doi:10.1111/ced.12147 Summary Aquagenic urticaria is a rare form of inducible urticaria characterized by wealing at the site of contact of the skin with water, regardless of its temperature, within min- utes of exposure. We describe six young women who reported urticarial rashes, trig- gered mostly by sea bathing, characteristically localized on the inferior facial contours and neck. In four of the six patients, this was the only localization. All six reacted with erythema and wealing to challenge tests with hypertonic saline (3.5% NaCl) applied to the submandibular area and/or neck. Two patients reacted also to tap water or to normal saline, but less intensely. Challenge tests with different hypertonic water solutions, performed in one patient, showed that both salinity and hypertonicity may be pathogenically relevant. Response to antihistamines was poor in three patients. Our experience suggests the existence of a distinct salt-dependent subtype of aquagenic urticaria (SDAU) that affects young women, with a character- istic localization on the inferior facial contours and neck. SDAU is possibly under- recognized and under-reported. Aquagenic urticaria (AU) was first described by Shelley and Rawnsley in 1964, 1 and about 50 cases have subsequently been reported. In 2001, we described a case of localized AU apparently dependent on the ionic concentration and/or osmolarity of water. 2 The patient was a young woman whose urticarial rashes were restricted to the lower facial contours, and were more intense on contact with sea water and hypertonic sal- ine than with tap water. We report six further cases with similar characteristics. Report Six women (mean  SD age 29.6  10.63 years, range 19–47 years) presented to us over a period of time, with each reporting that sea bathing induced fleeting, highly pruritic urticarial rashes on their face (periauricular, mandibular and/or submandibular regions) and neck. None had a family history of simi- lar symptoms. Three reported that the reaction some- times involved the upper chest and shoulders as well. The reaction cleared within 30 min after showering with tap water, except in one patient who experienced similar, although attenuated, symptoms from contact with tap water as well. Another patient reported prob- lems with both sea and swimming-pool bathing, but not with tap water. Application of a water-in-oil (W/O) barrier cream before sea bathing attenuated the rash in most of the patients, whereas antihistamines at standard dosage were effective only in three of them. The patients’ clinical characteristics, investigations and results are summarized in Table 1. All patients were challenged with tap water and with a hypertonic NaCl water solution (3.5%, iso- osmolar with sea water) at room temperature, by means of soaked compresses applied for 20 min to their mandibular region or neck, and also to the antecubital flexures as control areas. Additional challenges were performed in individual patients, depending on their willingness to undergo further Correspondence: Dr Rosella Gallo, Di.S.Sal. Section of Dermatology, University of Genoa, Viale Benedetto XV, 7, 16132, Genoa, Italy E-mail: rs.gallo@unige.it Conflict of interest: none declared. Accepted for publication 10 January 2013 ª 2013 British Association of Dermatologists 754 Clinical and Experimental Dermatology (2013) 38, pp754–757