Positive skin tests to pollen extracts of four species of Pistacia in Israel.

Fifty-eight atopic and nine non-atopic volunteers, all residents of the Tel Aviv metropolitan area, Israel, were skin tested with extracts made from filtered pollen of Pistacia atlantica, P. lentiscus, P. palaestina and P. vera. Twenty-four out of the fifty-eight patients examined (41.4%) had positive skin reactions to at least one of the four examined species of Pistacia: seven of the patients reacted to all the examined extracts, whereas the other seventeen reacted to only some of them. Fifteen patients reacted to extracts of P. atlantica, sixteen patients reacted to extracts of P. lentiscus, ten patients reacted to extracts of P. palaestina and seven patients reacted to extracts of pollen of P. vera. None of the healthy, non-atopic volunteers reacted to any of the extracts. To the best of our knowledge, this is the first report of immunological reactions to pollen extracts of the genus Pistacia.