Nature of physical urticaria manifestations
There are a variety of urticaria manifestations that can be caused by a variety of stimuli on skin, some of them are frequent and some of them rarely affect to one patient at most. Further are listed some types of physical urticaria and the detail of their symptomatology and characteristics.
Urticaria produced by low temperatures
This condition is also known as urticaria by cold and constitutes from three to thirteen percent of physical urticaria cases, there is an immediate variant and another that is delayed, in some cases this condition is considered as idiopathic. It is presented with the fast emergence of confluent hives over skin, neck and hands after the exposition to cold. The angioedema or anaphylaxis can happen in the case of a severe manifestation.
Generally it begins in an area that has been in contact with cold, like the application of ice over skin or with less frequency it also happens if the person is exposed to a decrement of environmental temperature, which triggers a more generalized reaction. Most of urticaria cases acquired by cold are idiopathic and are associated to hives of short lifetime. Secondary forms of this condition can be connected to cryoglobulinemia, these cases are very few, there are also cases for cold agglutinins or cryofibrinogen, on which cases hives can remain for a period of twenty four hours or for much longer.
These findings can provide a new light on the investigation of the underlying causes for this condition, like hepatitis B or C, infectious mononucleosis or lymphoreticular disease. The indicated test consists on applying a little cube of ice over the skin for a period of ten minutes.
Solar and Aquagenic urticaria
On solar urticaria the exposition of skin to sunlight or to an artificial source of light triggers the emergence of hives immediately while aquagenic urticaria takes place after the skin has entered in contact with water at any temperature.
Urticaria for contact
This is a term used to describe the presence of an immediate reaction after the skin has entered in contact with any type of substance. The urticaria for contact is classified based on the mechanism of production of the allergy. The allergic form appears on persons that have been previously sensitized by the causative agent, it could happen through digestive, breathing or cutaneous track as it happens with the Latex protein of certain rubber gloves. Latex proteins can also be auto-transported allergens as it has been shown in the inhalation of powder of the gloves. These patients can have a crossed reaction with fruits like avocado, kiwi and banana.
It can emerge as a local reaction or as a disseminated reaction with an involvement on the whole cutaneous surface and even with angioedema, asthma, rhinitis, anaphylaxis and conjunctivitis and in severe cases. This phenomenon is known as the syndrome of urticaria for contact. Some other allergens described are antibiotics like chloramphenicol, ampicillin, streptomycin, bacitracin, neomycin and penicilines; animal products, plants and chemical products.