A low-histamine diet could decrease symptoms and improve the quality of life for people with chronic spontaneous urticaria (CsU), according to Nicola Wagner, MD, of the department of dermatology at the Clinical Center Darmstadt (Germany) GmbH, Darmstadt, and her coauthors.

In their prospective study of 56 patients with a 3-month history of CsU (average 25 months) who followed a low-histamine diet for 3 weeks, 42 (75%) showed improvements in the urticaria activity score (UAS), compared to baseline. In nine patients (16%), disease activity remained the same, and five patients (9%) experienced worsening symptoms.

The primary endpoint, which was at least a three-point improvement in urticaria activity score, was reached by 34 patients (61%). Among these 34 patients, the average reduction in the UAS score during the last 4 days of the diet compared with the 4 days before starting the diet was 8.59 points (P less than .001), and dropped from 9.05 to 4.23 (P = .004) across the entire group ( J Eur Acad Dermatol Venereol. 2017 Apr;31[4]:650-5 ).

The low-histamine diet omitted food such as cheese, preserved meats, strawberries, raspberries, citrus fruit, bananas, kiwis, plums, papaya, and alcohol, and included foods such as dairy, vegetables, fresh meat, eggs, bread, pasta, rice, and certain varieties of fish. “Many patients with CsU complain of worsening of symptoms by consuming histamine-rich food, like red wine or matured cheese, but to the best of our knowledge, until now no studies were available supporting these observations,” the authors wrote.

The low-histamine diet was also associated with an average improvement in Dermatological Life Quality Instrument Questionnaire from baseline of 2.08 points across all participants, while Chronic Urticaria Quality of Life Questionnaire scores improved by an average of 5.46 score points in the 52 patients for whom these evaluations were available.

“Quality of life showed an improvement by a low-histamine diet, which was surprising, because dieting may decrease quality of life,” the authors noted.

There was also a reduction in antihistamine use among participants taking antihistamines at baseline, with 39% (22 of 56) reducing their intake and just over half of these patients (12 of the 22) stopping antihistamines altogether.

The study measured levels of diamine oxidase – the enzyme responsible for disintegrating histamine – both before and after, and saw no significant change across the patient group. However, patients with higher urticaria activity scores at baseline did show a decline in diamine oxidase activity with the diet.

Addressing concerns that these improvements could simply reflect spontaneous remission of the disease, the authors pointed out that a previous study had found a remission rate of just 3.4% over 6 months.

Based on the results, they concluded that a low-histamine diet “might be recommended for a period of 3-4 weeks in CsU patients in order to reduce symptoms and antihistamine intake as well as to improve quality of life.”

The authors had no funding source or conflicts of interest to declare.