Quillaja bark (soapbark)--induced asthma.

A 24-yr-old man developed sensitization to Quillaja bark (soapbark) dust at his work place. Within 3 mo of being employed in a factory processing Quallaja bark to produce saponin, he experienced asthma symptoms while handling the bark but only nasal symptoms on being exposed to the purified saponin. Bronchial provocation using Quillaja bark dust resulted in immediate bronchoconstriction as well as faintness, diffuse erythema, and hypotension. Radioallergosorbent test (RAST) using the pulverized crude Quillaja bark was markedly positive, and cross-reactivity between gum acacia and gum tragacanth was demonstrated using this technique.