Box 2.

Evidence that tick bites are a or the major cause of IgE responses to alpha-gal

I. The area of the USA where the IgE antibodies are common, coincides with the distribution of the lone star tick

II. A large proportion of patients with these antibodies report prolonged itching after tick bites

III. In four cases we have followed increases in IgE antibodies to alpha-gal after tick bites

IV. IgE to alpha-gal correlates strongly with IgE to extract of the lone star tick

V. In other countries bites of ticks of other species have been associated with IgE to alpha-gal

VI. Among populations living in large cities of the USA or the extreme north of Sweden where ticks are not present, IgE antibodies to alpha-gal are absent

IgE antibodies to alpha-gal can be measured with cetuximab on a streptavidin CAP (see Ref 10). The assay is also available commercially from IBT/Viracor (Lee's Summit, MO).