 "Ulocladium botrytis" is currently regarded as a source of home allergen sensitization and is used in skin-prick tests that test for mould allergens and work-related allergens.This is due to the production and detection of Alt a 1, the major allergen produced by "Alternaria alternata", in "U.botrytis".In addition, "U. botrytis" also releases another allergen, homologous to Alt a 1, that possesses the capacity to cause allergic responses in humans.