Airborne mold monitoring in three cities in Saudi Arabia has documented the presence of Cladosporium in high concentrations. The spore counts reached threshold levels for sensitization at Jeddah and Al-Khobar with prominent seasonal variations. The concentration in Riyadh (central region) showed levels with minor fluctuations and a minor peak towards the month of November. Indoor monitoring also revealed the presence of Cladosporium. Ten species of Cladosporium were identified with C. sphaerospermum, C. herbarum, C. cladosporoides and C. macrocarpum being most prevalent. The species are relevant in relation to extracts for diagnosis. Skin testing of asthmatic children in Riyadh and Makkah revealed reactivities to Cladosporium extract of 5.8% and 31.3%, respectively. This indicates that Cladosporium may be an important allergen in the region that necessitates further biochemical and immunochemical studies to confirm the allergenic impact of the species of Cladosporium prevalent in the region. The regional prevalence of mold allergies varies considerably. In northern latitudes, 4% to 10% of atopic patients react to the common mold allergens, whereas in more southern countries, 20% to 30% mold reactivity has been reported.2 Molds are ubiquitous in nature, and the occurrence of various species of fungi in outdoor and indoor environments from many parts of the world has been reported. 3 Occurrence of some fungi in the Saudi environment has also been reported. 4,5 Cladosporium (CLD) is among frequent causes of mold allergy. 6 The amount of mold spores in the air is quite variable and related to the life cycle of local crops, foliage, dead plant particles as well as seasonal fluctuations in temperature and humidity.Case histories of patients with mold allergy may be quite variable, since other sensitivities may confuse the matter. Most of the mold sensitive patients show frequent symptoms over long periods due to continuous exposure to the allergens. To investigate mold allergy in a certain geographical region, the prevalent mold spores have to be considered. The allergen panel should then be selected based on the findings along with the patient's clinical history.For the diagnosis of mold allergy, the skin prick test is still widely used. 7 However, the reliability of this test is hampered by large variations in allergenic extract quality. This is complicated further by the presence of different species of the same mold genus. With regard to CLD, 62 species have been recognized. 8,9 Different commercial allergen manufacturers use different species. In addition, it is often experienced that mold extracts cause nonspecific skin reactions due to their content of nonallergenic skin irritating components. Positive skin tests can be confirmed by determination of specific IgE-antibodies by radioallergosorbent test (RAST). Inhalant provocation test can also be used in selected cases. However, this assay is often very cumbersome and time consuming. It has been shown that in patients with asthma induced by molds, the results o...

The fungal flora contains diverse organisms including a large number of fungi, molds, mushrooms, yeasts, rusts, and smuts etc. Airborne fungi are important source of indoor allergens and studies confirm their role in the development of allergic diseases. In order to identify indoor fungal allergens, 539 house dust samples were collected from different regions in Saudi Arabia. Samples were analyzed by culture employing Sabouraud Dextrose and Potato Dextrose Agar. The cultivated plates were incubated at 25°C up to 5 days. Colony forming units (CFU) were enumerated and identified.Various fungal species were identified from the samples. The majority of fungi identified belonged to the allergenic genera. Aspergill us niger constituted 38.5%, A. fumigat us 15.5%, Rhizopus spp 14.5%, Penicillium spp 8%, Aspergill us spp 7.1%, Alternaria spp 4.4%, Yeast 4%, Mucor 3%, Cladosporium spp 2%, Fusarium spp. 1%, and other minor type include A. flavus 2%. The noncoastal cities (n=455) showed a higher percentages than coastal cities (n=84) because of difference in sample collection.Public places, primarily mosque, was included in the study. Out of 104 samples, Aspergill us niger constituted 39%, Rhizopusspp 14%, Aspergill us fumigat us 12%, Alternaria spp 10%, Fusarium sp. 8%, Penicillium spp 6%, As pergill us spp 6%, Ulocladium, Bipolaris and Yeast 2%, Mucor, Cladosporium spp and Drecslera spp. 1%.Exposure to certain fungal species cause sensitization and allergic reactions and may increase severity of asthma symptoms. Therefore, proper avoidance strategy need to be adopted with a regular cleaning of storage area and humidity control measures, if possible.