Serum IgE levels in forty families studied for two or three years.

Serum IgE levels have been measured over two to three years in 210 individuals. In one-fifth IgE levels remained remarkably constant, in one-quarter they rose and in half they fell. A rise was usually associated with the development of fresh atopic disease, exacerbation of established disease or dependence on symptomatic treatment. A fall was associated with a diminution in the severity of symptoms occurring spontaneously as a result of good environmental control or of appropriate immunotherapy. Sequential IgE levels provide confirmatory evidence of the success of either environmental control or of immunotherapy.