Aquagenic urticaria: report of a case and review of the literature Khanh vinh quoc Luong, MD, FACP and Lan Thi Hoang Nguyen, MD Objective: To present a case of aquagenic urticaria and to review the literature regarding this very rare physical urticaria. Method: We described the clinical history of a patient with aquagenic urticaria. A water challenge test was performed, with plasma histamine levels measured before and after the challenge. Result: Our patient presented with a history of severe itching and wheals within five minutes of contact with water, regardless of its temperature or source (sea or tap water). A water challenge produced hives but serum histamine levels did not change. Prophylaxis with antihistamine or anticholinergic medications was not effective. Conclusion: Exposure to water can cause urticaria in susceptible patients and antihistamine and anticholinergic medication may not prevent the reaction. The mechanism of this phenomenon remains poorly understood. Ann Allergy Asthma Immunol 1998;80:483–5. INTRODUCTION Water is an essential constituent of the human body. Contact of the skin with water is an unavoidable condition. This contact is considered harmless and often pleasurable. It is difficult to realize that some people may react ad- versely to contact with water. For a small number of patients, contact with water at any temperature may be asso- ciated with cutaneous discomfort, such as pruritus and urticaria. 1,2 In the present paper, we report a case of aquagenic urticaria (AU). CASE PRESENTATION A 20-year-old Vietnamese male had suffered headache, respiratory distress, severe itching, and wheals within five minutes of contact with water. These symptoms would occur regardless of temperature or source (sea or tap wa- ter) of water. The urticaria usually lasted for approximately 15 to 20 min- utes. The lesions occurred on almost all parts of the body except for the palms and soles; however, he was able to drink water without problem. The problem had been present persistently for over the last 10 years. Some doc- tors told him that he had a “psychogen- ic problem” when he sought medical ad- vice about his illness. There was no personal or family history of atopy. A general physical examination yielded no abnormal findings, except for dermogra- phism. Laboratory studies including se- rum chemistry and electrolytes, blood counts and thyroid function tests were normal or unrevealing. The serologic studies were negative for rheumatoid factor and syphilis. A water challenge test was applied by washing patient’s face with cool tap water at room temperature. His face developed small punctuate wheals (1 to 2 mm in diameter) on an erythema- tous base in the area of contact with water within five minutes. He had as- sociated headache and shortness of breath with bilateral wheezing on aus- cultation. The urticaria spontaneously resolved without residue after 20 min- utes. Plasma histamine was collected with result as follows: before water challenge, 74 ng/mL (normal, 25–175) and during urticaria, 88 ng/mL. The patient failed to respond to pro- phylaxis with antihistamines (terfena- dine and hydroxyzine) and anticholin- ergic agents (scopolamine patch). He avoided swimming and learned to bath rapidly and to dry himself quickly. DISCUSSION Aquagenic urticaria is a rare form of physical urticaria in which contact with any source of water (for example, sea or tap water) evokes hives. The condition must be differentiated from aquagenic pruritus, first described by Greaves et al, 1 in which contact with water induces itching without cutane- ous lesions. In AU, tap and distilled water appear to be equally effective in evoking wheals 2–5 ; while direct contact with ice for 15 to 300 seconds or application of ice cubes in a thin plas- tic film produced no urticarial re- sponse. 2,6,7 There was one reported pa- tient who had no urticaria when swimming in the ocean. 8 Urticarial re- action did not occur with either ace- tone or absolute acetone when these substances were applied locally for 5 minutes 2–6 ; this observation indicated that organic solvents did not evoke the reaction as the water did. These same experiments showed that pretreatment of the skin with organic solvents en- hanced the subsequent urticarial re- sponse to challenge with water. A so- lution of lanolin, mineral oil, and a nonionic emulsifier in bath water greatly reduced the number of hives. 6 Intradermal injection of triamcinolone acetonide also prevented the develop- ment of wheals after contact with wa- ter. 9 Approximately 25 cases have been reported in the medical literature (Table 1). Familial AU was noted in some patients. 2,5,6,7,10 Serum IgE and complement C1-esterase inhibitor lev- els were normal. Females were affected more often than males (Table 1). Of interest, dermographism may be present, especially in male patients Received for publication September 5, 1997. Accepted for publication in revised form April 13, 1998. VOLUME 80, JUNE, 1998 483