Chronic hives or chronic spontaneous urticaria or chronic idiopathic urticaria or chronic autoimmune urticaria is characterized by moving, itching wheals that occur with variable frequency for 6 weeks duration or more.
It can occur in adults and pediatrics, but it is more common in adults. It is usually a primary condition, but rarely present secondary to another source of inflammation. History and physical examination are important to exclude drug reactions, hypothyroidism or a connective tissue disorder. The role of laboratory testing is of uncertain value of finding a cause. Limited evaluation can include a complete blood count (CBC), erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), liver enzyme and thyroid stimulating hormone (TSH). Other studies that have been done are complete/basic metabolic chemistry, Helicobacter pylori antibody, thyroglobulin antibody, microsomal antibody, tryptase, antinuclear antibody, IgE, serum protein electrophoresis, urinalysis, serum-specific IgE, skin prick testing and skin biopsy. Newer tests include anti-IgE receptor antibody chronic urticaria index.
The average costs of lab work up for chronic hives has been shown to cost $573 with only 0.16% of tests resulting in improved clinical outcomes.
Chronic hives affects up to 1% of the general population at any given time. For patients suffering from the illness, there is often significant impairment in quality of life, sleep disturbances and anxiety. Many patients achieve remission after 1 year of treatment, although some may continue after 5 years. Most patients have no identifiable cause although most patients seek medical consultation with the expectation that a cause will be found. Case reports suggest a potential of associations including food, drug, and dye/additive allergy, various forms of cancer, connective tissue disease, thyroid disease, parasitic infections, and vitamin D deficiency. However in the majority of cases no cause is found despite an expensive workup.
A focused history and a clinical examination of the rash is most important to identifying hives and its treatment. Clinical improvement from laboratory testing is very low for chronic hives and it is not cost effective.