Aquagenic urticaria in twins

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.

Omalizumab as a treatment option for antihistamine-refractory aquagenic urticaria

A teenage girl presented with symptoms of itching and hives on contact with water for 3 years. On specific provocative testing and ruling out underlying systemic conditions, she was diagnosed with aquagenic urticaria. Following failed attempts to control her symptoms with second-generation antihistamines, she was started on monthly subcutaneous injections of the monoclonal antibody, omalizumab. The patient demonstrated significant improvement, with symptoms being well-controlled for 2 years now. She enjoys a good quality of life and can take a shower without developing itching or hives.

Aquagenic urticaria: Water, friend, or foe?

There are <100 reported cases of aquagenic urticaria. Although most are sporadic, several diseases have been associated. Diagnosis is based on provocation tests. Second-generation antihistamines are the first-line treatment.

Water-related dermatoses

Water-related dermatoses are a spectrum of diseases that are associated with water exposure. They result either from the direct influence of water or after injury from water inhabitants. In this review, clinical entities that manifest after water exposure (aquagenic pruritus, aquagenic urticaria, and aquagenic wrinkling of the palms) will be discussed with particular focus on the reported pathogenesis. Aquatic organisms and activities can be linked to cutaneous injuries that require identification and distinct management. Marine and freshwater dermatoses were summarized to provide physicians with easy access to the causative organism, method of injury, and appropriate management.

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

An 18-year-old male visited our department complaining of recurrent episodes of an itchy rash after hand washing, showering/bathing, drinking water, and getting rain-soaked. He was diagnosed with aquagenic urticaria after a water provocation test and histopathologic examination. Five months of antihistamine treatment successfully prevented further wheal formation. Aquagenic urticaria is a very unusual form of physical urticaria caused by contact with water. It manifests as pruritic small wheals surrounded by erythema within 30 minutes of exposure. The condition can be diagnosed by a water provocation test. Systemic antihistamines are the first-line treatment, with anticholinergics, phototherapy, or barrier cream used alternatively or additionally. Four cases of aquagenic urticaria have been reported in Korea, but no histopathologic evaluation was reported in the English or Korean literature. Herein, we provide both a case report of aquagenic urticaria diagnosed by the water provocation test and histopathologic examination results for this patient.

Aquagenic urticaria: diagnostic and management challenges

Aquagenic urticaria (AU) is a rare inducible form of physical urticaria, which occurs in response to cutaneous exposure to water, including sweat and tears. Patients present with characteristic 1–3 mm folliculocentric wheals with surrounding 1–3 cm erythematous flares within 20–30 minutes following skin contact with water. In rare cases, there are concomitant systemic symptoms, such as wheezing or shortness of breath. The pathogenesis of AU is poorly understood at this time, and it appears to be mediated in both a histamine-dependent and independent manner. Diagnosis is based on eliciting a thorough clinical history combined with a water challenge test. Some patients may need to undergo further testing to exclude other physical urticarias. Rarely, multiple physical urticarias can be present in one patient, which can complicate diagnosis and treatment. Currently, the first-line therapy for AU is an oral administration of nonsedating, second-generation H₁ antihistamines, but many patients may require further interventions to have adequate symptomatic control. In this review, we discuss the diagnostic and management challenges of AU. We review the key diagnostic features that differentiate AU from other physical urticarias. We additionally describe a therapeutic ladder for the treatment of AU and the rationale supporting these treatments.