Cladosporium and respiratory allergy: diagnostic implications in Saudi Arabia.

An allergological study to evaluate allergenicity to Cladosporium, Burkard 7-Day Volumetric Spore Trap and Personal Volumetric air sampler (viable mode) were employed to conduct air sampling for 12 months in three regions of Saudi Arabia. The study was extended for a continuous 3rd year at one site. Skin prick testing (SPT) was also conducted on 605 allergic individuals using commercial extracts of C. herbarum. Cladosporium emerged to be the most prevalent genus in the outdoor environment constituting up to 25% of all fungal spores in the dry region and 37.1 and 41.2% in two coastal cities respectively. Amongst the species C. sphaerospermum, C. macrocarpum, C. cladosporioides and C. herbarum were noted. Maximum hourly concentrations up to 14 x 10(3) m(-3) were recorded in coastal region during winter months. Morning concentrations were higher at both city sites compared to afternoon concentration. SPT result revealed an overall 19.67% positive reactions with majority showing mild reactions.