Favism

Abstract

The term ‘favism’ is used to indicate a severe reaction occurring on ingestion of foodstuffs consisting of or containing the beans of the leguminous plant Vicia faba (fava bean, broad bean). Within 6–24h of the fava bean meal, the reaction manifests itself with prostration, pallor, jaundice, and dark urine. These signs and symptoms result from (sometimes massive) destruction of red blood cells (RBCs; acute hemolytic anemia), triggered by certain glucosides (divicine and convicine) present at high concentrations in the fava beans. These glucosides cause severe damage to RBCs only if the cells are deficient in the enzyme glucose-6-phosphate dehydrogenase (or G6PD); therefore, favism occurs only in people who have inherited G6PD deficiency. Favism is more common and more life-threatening in children (usually boys) than in adults; however, once the attack is over, a full recovery is usually made. In a person who is G6PD deficient, favism can recur whenever fava beans are eaten, although whether this happens or not is greatly influenced by the amount of beans ingested and probably by many other factors. From the public health point of view, it has been proven that favism can be largely prevented by screening for G6PD deficiency and by education through the mass media.