An allergist looks at urticaria.

Some etiologic possibilities which must be considered are foods, drugs, infection, inhalant sensitivity, psychic factors, physical agents, underlying connective tissue disease or neoplasm, insect bite or stings and genetic abnormalities. A painstaking history and a complete physical examination are, of course, mandatory. These are followed by appropriate studies for whatever etiologic factors are suggested by the history and physical examination. Certain routine or more sophisticated studies might be indicated including a complete blood count, urinalysis, stools for ova and parasites, antinuclear antibody titer, complete complement, sedimentation rate, sinus, chest and dental X rays and any other specified test depending on where the clues lead. O'Loughlin described a practical approach in the use of laboratory studies for the diagnosis of chronic urticaria. Skin tests can be helpful especially for inhalants, but food tests are usually not reliable in the diagnosis of chronic urticaria. The acute urticaria reaction to a food is clinically obvious and this type of patient does not usually seek medical attention or need extensive investigation. Treatment includes a few basic medications. Hydroxyzine (Atarax, Vistaril), which combines tranquilizer and antihistamine action, is frequently effective. Cyproheptadine HCL (Periactin) both a serotonin and histamine antagonist with anticholinergic effect, is also helpful--especially in combination with hydroxyzine. Antihistamines, ephedrine, epinephrine, aminophyllin and occasionally corticosteroids are helpful. Immunotherapy with inhalants is occasionally indicated. Eliminating possible offending foods, dyes or drugs has been previously discussed. Anti-candidal therapy and low yeast diet is effective when indicated. The final aspect of the investigation and treatment process might best be described as "patient support"--patience on the part of the physician. It should be realized that in 75% of the cases of chronic urticaria, no convincing etiology is found. It should also be realized that urticaria all too frequently "settles down" due as much to the natural course as to the careful ministrations of the physician.