Timeline Event - year 1996 Evidence describing how mite droppings can cause ‘allergic-like’ symptoms before true allergy develops.   A scientific report on how enzymes found in house dust mite droppings can cause ‘allergic-like’ symptoms before true (specific IgE) allergy develops. The possibility of a vaccine is considered as a remedy. Reference ‘Potential allergens stimulate the release of mediators of the allergic response from cells of mast cell lineage in the absence of sensitisation with antigen-specific IgE’ Machado DC, Horton D, Peachell P T, Helm B A, Eur J. Immunol. 1996, 26, pages 2972 to 2980