Solar urticaria

What is solar urticaria?
Solar urticaria is a rare photodermatosis characterized by itching, stinging, erythema and papule formation after a short period of exposure to natural sunlight or artificial light source which emits wavelengths closer. It is located on sun-exposed areas, although it can appear on skin covered with thin coats. Solar urticaria disappears within a few minutes to hours, without pigmentary changes when exposed to sunlight should be avoided. This disease can be very debilitating and difficult to control. Often has a sudden onset, dramatic. There is little information about the duration and outcome.
Solar urticaria comprises only 4% of patients with diseases photosensitising. The mortality rate has not been determined. In some cases the skin eruption is accompanied by symptoms such as headache, nausea, vomiting, bronchospasm, and syncope.
Solar urticaria is caused by an antigen-antibody reaction. Solar radiation can induce an antigen in plasma or serum of patients. Intradermal injection of serum from a patient with solar urticaria, passive transfer provided a healthy person. In rare cases systemic medical supportive measures to maintain adequate ventilation and blood pressure are necessary. Avoid sun exposure. as solar urticaria involve histamine release IgE degranulation first treatment is administration of antihistamines. phototherapy is also used UV-A, UV-B band and fotochimioterapia long or short. Desensitization treatments are usually performed in the spring. Therapies are long-term and short-term potency.
Solar urticaria is a chronic disease. Few patients experienced spontaneous remission. Continuous oral administration of antihistamines can prevent urticaria and allows a degree of tolerance sun. Long-term improvements in patients using phototherapy obsrervate or fotochimioterapia. Pathogenesis and causes solar urticaria Solar urticaria can be caused by an antigen-antibody reaction. Solar radiation can induce the formation of an antigen in serum and plasma of persons affected. Intradermal injection of serum of a sick person healthy condition before transfer.
They proposed the following types of solar urticaria: - Type I solar urticaria: this is an IgE-mediated hypersensitivity to specific photoallergen generated only in patients with solar urticaria - Type II solar urticaria: this is an IgE-mediated hypersensitivity to nonspecific photoallergen found in solar urticaria and in healthy individuals.
Passive transfer test results are positive in patients with type II urticaria, but may be positive or negative type I patients with broad-spectrum (290-800 nm) involved in this condition may be associated with specific and weight fotoalergenii to molecular. Diversity in action spectrum may be due to differences photoallergen reported. In addition, the spectrum appears to be responsible for inhibition or augmentation reactiei.Apar complex interactions between different wavelengths and photoallergen. The result of these actions is mast cell degranulation with secondary release of histamine. Besides histamine and other mediators may be involved. Inhibition of solar urticaria suppress the light response of edema after intradermal injection of autologous fotoacitvati, but not suppress the response of erythema and edema appeared to compound 48/80.