en.aazsante.fr

The Largest Portal Of Health And Quality Of Life.

Water allergy (aquagenic urticaria): know this rare disease

Water allergy (aquagenic urticaria): know this rare disease

Aquagenic urticaria, known popularly as a water allergy, is a type of physical urticaria in which contact with water, regardless of temperature or its source, causes a skin welt 20 to 30 minutes after exposure. Symptoms last 30 to 60 minutes and disappear spontaneously. The lesions occur in the form of small follicular (itchy) and reddened skin elevations (papules), often confused with typical eruptions of cholinergic urticaria, which appear after exercise, emotional stress, sweating, and heat. This "water allergy" appears especially on the trunk and upper limbs, sparing palms and soles. Patients rarely have systemic symptoms such as wheezing or shortness of breath. When these symptoms appear, urticaria appears to be more dramatic, also exhibiting large red plaques in the body and edema.

Who is at most at risk of presenting the condition?

The prevalence of water allergy, or aquagenic urticaria, is higher in females, especially during puberty and post-puberty. It has rarely been associated with systemic diseases such as HIV infection and thyroid carcinoma. There are reports of coexistence with Bernard-Soulier syndrome (hereditary hemorrhagic disease), suggesting the possibility of association with genetic alteration, but no specific gene has been identified so far.

It is worth mentioning that this is a very

But the allergy can happen in any contact with water?

There are patients who present a reaction depending on the salinity of the water: that is, they can present a reaction with tap water, snow, fresh water, but can swim in sea water without hives. Other patients may have urticaria only in contact with salt water.

If a person takes a shower or shower, he or she may have urticaria, but with treatment, symptoms can be controlled.

If people drink water , the development of urticaria will not occur. This disease only happens after the contact of water with the skin and not with the mucous membranes of the mouth and digestive tract.

Causes of water allergy

The first hypothesis of the cause of this allergy came in 1960, would be that the water would react with the sebaceous glands forming a toxic substance that would stimulate the degranulation of the mast cell with histamine release, which would trigger lesion formation. In 1981 a new hypothesis would suggest that a sudden change in the osmotic pressure of the hair follicles would lead to a passive increase in water diffusion. This change in pressure would result in urticaria. Recent hypothesis of the author Gallo and collaborators would be the existence of water soluble antigens in the epidermis that dissolve and diffuse through the dermis resulting in release of histamine. But the more recent hypothesis of Luong and Nguyen of 1998 suggests a mechanism completely independent of the release of histamine causing urticaria.

How is the diagnosis and treatment for water allergy

The diagnosis is based on the clinical history of recurrence of urticaria after exposure to water with positive water challenge test. This test consists of the application of tissue moistened with water at room temperature for 20 minutes on the skin. If urticaria appears after this period the test is considered positive. It is necessary to differentiate aquagenic urticaria from urticaria to heat, cold, pressure and cholinergic, but the association of allergy to water with any other type of physical urticaria may occur.The most usual treatment is the use of second generation antihistamines, which are considered non-sedating, therefore do not cause sleep, and have a longer duration of action than first generation. Application of emulsions of oil in water and petrolatum in bath cream may be used. Phototherapy can also be used as therapy.


Microcephaly in infants: what is the relationship with the Zika virus?

Microcephaly in infants: what is the relationship with the Zika virus?

The sudden increase in the number of cases of microcephaly, a rare neurological condition usually identified during the gestation phase, has been warning Brazilian medical authorities. According to the Ministry of Health, while between 2010 and 2014 a total of 781 cases were registered in all countries, during the year 2015 there were registered 2,401 cases of the disease and 29 deaths in 549 municipalities in Brazil, according to the epidemiological bulletin released on the day December 15th.

(Health)

Focus on goals reduces chance of dementia in old age

Focus on goals reduces chance of dementia in old age

If you are looking for a way to drive dementia away, a new study suggests staying true to achieving a goal. The finding, published in the Archives of General Psychiatry suggests that people who have goals to follow seem less affected by brain changes that could contribute to the development of diseases, such as Alzheimer's.

(Health)