Aquagenic Urticaria Diagnosed by the Water Provocation Test and the Results of Histopathologic Examination

A Systematic Review of Aquagenic Urticaria-Subgroups and Treatment Options

BACKGROUND

Aquagenic urticaria (AquaU) is a rare variant of chronic inducible urticaria where wheals occur after skin contact with water. Information on clinical manifestations and treatment outcomes is limited, which makes the management of AquaU challenging.

OBJECTIVE

To systematically review disease features and relevant triggers of AquaU and patients' response to treatment.

METHODS

Related articles were searched by use of the terms "aquagenic urticaria" and "aquagenic angioedema" until June 2021 and reviewed according to Preferred Reporting Items for Systematic Reviews and Meta-Analysis recommendations.

RESULTS

A total of 77 patients with AquaU were investigated in 59 studies including 47 case reports and 12 case series. AquaU predominantly presented in women (47 patients, 61%), and the mean age of onset of the disease was 19.6 ± 10.8 years (range: 0-54 years). Wheals commonly occurred in localized areas and regardless of the water temperature. Based on the reviewed evidence, AquaU can be classified as familial AquaU (FAquaU, 18.2%) and acquired AquaU (AAquaU, 81.8%). Although many treatments were used in both subtypes of AquaU, the use of second-generation H₁ antihistamines (2^ndAH₁) was reported most often to achieve marked improvement in both subtypes. The use of topical therapies in AquaU, which most commonly use hydrophobic vehicles, is poorly documented and of controversial efficiency.

CONCLUSIONS

AquaU is proposed to be classified into 2 subtypes, FAquaU and the more common AAquaU. Treatment with a 2^ndAH₁ is recommended as the first-line treatment for both types of AquaU. Further studies are required to fill knowledge gaps.

Case of aquagenic urticaria: Case report and the results of histopathological examination

Aquagenic urticaria (AU) is a rare skin condition in which dermal contact with water serves as a trigger of urticaria and pruritus. To make a diagnosis, a water challenge test is useful. We herein report a 16-year-old Japanese boy diagnosed with AU by water provocation test. The induced skin lesion histologically showed prominent degranulation of mast cells and lymphocytic infiltration throughout the dermis. This is the second report documenting the histopathological features of AU.

Management of chronic urticaria in children: a clinical guideline

The aim of this guidance is to provide recommendations to clinicians and other interested parties on chronic urticaria in children. The Italian Society for Pediatrics (SIP), the Italian Society for Allergy and Immunology (SIAIP), the Italian Society for Pediatric dermatology (SIDerP) convened a multidisciplinary panel that prepared clinical guidelines for diagnosis and management of chronic urticaria in childhood. Key questions on epidemiology, natural history, diagnosis, and management were developed. The literature was systematically searched and evaluated, recommendations were rated and algorithms for diagnosis and treatment were developed. The recommendations focus on identification of diseases and comorbidities, strategies to recognize triggering factors, improvement of treatment by individualized care.