Pollinosis related to Zygophyllum fabago in a Mediterranean area

Zygophyllum fabago is a herbaceous plant withairborne pollen found widely in the MurciaRegion, in the Southeast of Spain. Although itsallergenicity has been recently reported,little is known of its involvement inpollinosis. Aerobiological study andsensitization in pollinotics weremeasured using a Hirst volumetric trap. Wehave measured the atmospheric concentrationsof this pollen and other allergenicpollen types in our region, between March 1993 andMarch 1997. Z. fabago pollen wascollected for a morphometric study of thepollen grain, and a lyophilized extract wasprepared for skin prick tests. We haveconducted skin tests with different pollen typesfrom our region and with Z. fabago in1736 patients with symptomssuggesting pollinosis. The size of the pollengrain averages 15.17 × 17.35 µm. Thepollination period extends from May to August,with a mean accumulated concentration of 448grains/m³. Out of 1736 pollinotics,263 (15.15%) showed a positive skin test forZ. fabago, 6 were monosensitized and 257were sensitized to other common pollen types fromour Region. Specific IgE to Z. fabago wasequal or higher than 0.35 ku/l in 86.56% ofsensitized patients. Chenopodiaceae pollinateduring spring and autumn and sensitize a largernumber of patients; Urticaceae reach thehighest pollen concentrations for a longerperiod but are not the primary cause ofpollinosis. This study shows that Z. fabagopollen becomes airborne, elicits an IgEresponse and, like other pollens, contributestowards triggering allergic symptoms.It should therefore be considered arelevant allergen and accordingly beincluded in skin test procedures.