The present invention relates to a diagnostically useful carrier comprising ameans forspecifically capturing an antibody to Ara h 7 isotype 7.0201 in a sample froma subject; amethod comprising the step detecting in a sample from a subject the presenceor absence ofan antibody to Ara h 7 isotype 7.0201 and a pharmaceutical compositioncomprising Ara h 7isotype 7.0201 or a variant thereof.