The occurrence of indoor allergens in Saudi Arabia.

Investigations on indoor airborne allergens in Saudi Arabia were performed by mold cultures and dust analyses by counter-current immunoelectrophoresis. Twenty fungal genera were isolated, with Aspergillus as the most often encountered. Most of the dust-bound fungi found are ubiquitous and common. Antibodies against Dermatophagoides pteronyssinus, cat- cow- and rat dander, and Cynodon dactylon pollen were used in the dust analyses. Animal antigens were found in five of the ten dust samples. House dust mites were extraordinarily rare. Pollen of Cynodon dactylon (Bermuda grass) was present in nearly all the samples, and in a concurrent clinical study this antigen was found to be the most common cause of perennial rhinitis.