Total IgE is in principle the sum of circulating specific IgE. In rare cases, like in myelomas, an extremely high titer of unspecific IgE is present, which has no relation to allergy. Certain parasites trigger a parasite-specific IgE response and may also nonspecifically stimulate IgE production. In cases with high total IgE and negative specific IgE results clinical history should be reconsidered.