Aquagenic urticaria characteristics
This is a type of physical urticaria which is not described very frequently and which emerges as a consequence of a slight contact of the skin of the patient with water (independently from the temperature) inducing locally and in an immediate way the appearance of an urticaria hive with a morphology very similar to cholinergic urticaria. The pathogenesis for this condition is not very well known. On these patients it has been found levels of histamine and the degranulation of mast cells in areas of skin that have been in contact with water. Besides there have been described cutaneous tests (intradermal) and of histamine releasing of positive basophils in an extract from human epidermis.
This information suggests that patients affected by aquagenic urticaria react in the presence of an antigen which is present on the epidermal corneum stratum, which when is solubilized in water reaches mast cells in the dermis producing the releasing of histamine. In some cases the cutaneous response to water can be inhibited through a pre-treatment with atropine, it suggests that in this type of reaction can also be involved the acetylcholine.
Clinical manifestations of Aquagenic urticaria
It is manifested by the emergence of small hives of one to three millimeters of diameter with an erythematous halo and pruritus in five to thirty minutes after the exposition to water, independently from the temperature of water. Episodes for this condition generally disappear spontaneously after fifteen or thirty minutes have passed and are preferably localized in the upper third of the neck, chest and arms.
In general symptoms can be mild and they are not accompanied of systemic manifestations. In some cases it has been found a family trend.
Diagnosing Aquagenic urticaria
The diagnostic for this condition can be confirmed by the application of a compress soaked with water at thirty five Celsius degrees and maintained on the upper third of the back during fifty to thirty minutes, observing the emergence of lesions that are typical of this condition in just a few minutes.
The differential diagnosis must be done with:
- Pruritus caused by water, clinical entity on which a slight contact with water produces and intense pruritus, but unlike the case of Aquagenic urticaria, it is not accompanied by visible lesions in skin and it is generally localized on lower extremities.
- Cholinergic urticaria, on which lesions are very similar but unlike to Aquagenic urticaria, these are triggered with exercise, heat and stress. However some patients can have associated both types of urticaria.
- Cold urticaria on which hives can emerge after the exposition of skin to cold water, but not to the exposition to warm or hot water.
In many cases a treatment for this condition is not required since the annoyances caused by it are slight and self-limited, being relatively tolerable by patients. If the symptomatology presented by the patient is more intense you can use oxy hives since this is a natural and very effective treatment for hives caused by urticaria.