Cladosporium as an Airborne Allergen in Saudi Arabia

Abstract

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...

Vegetation: A source of air fungal bio-contaminant

“…Nilsson (1990) and Chin-Shan et al (1995) mentioned that Alternaria, Aspergillus, Cladosporium, Curvularia, Fusarium, Mucor, Penicillium and Epicoccum are allergenic agents. Some Cladosporium species (C. herbarum) have been noted as a primary agent responsible for allergies and asthma in humans (Hasnain et al, 1994). Auger et al (1994) reported that Penicillium brevicompactum, P. cyclopium and Trichoderma were isolated from the residence of an individual who showed chronic fatigue.…”

Airborne allergenic fungal spores and meteorological factors in Greece: Forecasting possibilities

“…Airborne spores of the fungi Alternaria and Cladosporium have been documented as highly allergenic agents in Thessaloniki, Greece (Gioulekas et al 2004), similarly to other locations worldwide (Hasnain et al 1994;Targonski et al 1995;D'Amato et al 1997;Halonen et al 1997;Corsico et al 1998;Resano et al 1998;Verini et al 2001;Mari et al 2003). Many researchers relate the occurrence of respiratory allergy symptoms with the presence of these spores in the ambient air (Kauffman et al 1995;Downs et al 2001).…”

“…were selected, as these comprise the most abundant in the air of Thessaloniki (Gioulekas et al 2004). Also, the fungal spores of Alternaria (O'Hollaren et al 1991;Kauffman et al 1995;Targonski et al 1995;D'Amato et al 1997;Halonen et al 1997;Corsico et al 1998;Resano et al 1998;Downs et al 2001;Verini et al 2001;Mari et al 2003;Bush & Prochnau, 2004) and Cladosporium (Hasnain et al 1994;D'Amato et al 1997;Resano et al 1998) are considered as the most commonly implicated to respiratory allergy symptoms worldwide, including the area of Thessaloniki (Gioulekas et al 2004).…”

“…Fungal spores of specific taxa are very often implicated in respiratory allergy symptoms (Solomon, 1978;Hasnain et al 1994;D'Amato et al 1997;Halonen et al 1997;Corsico et al 1998;Resano et al 1998;Mari et al 2003;Gioulekas et al 2004). Mostly fungal spores -and not pollen grainshave been reported to be responsible for hospital admissions related to asthma attacks or even acute respiratory failure (O'Hollaren et al 1991;Kauffman et al 1995;Dales et al 2000;Bush & Prochnau, 2004); hence, these kinds of respiratory diseases are usually well documented for children and young adults (O'Hollaren et al 1991;Targonski et al 1995;Dales et al 2000;Downs et al 2001;Verini et al 2001;Bush & Prochnau, 2004).…”

Prevalence of airborne basidiospores in three coastal cities of Saudi Arabia

“…A few earlier studies in Saudi Arabia (Al-Frayh et al, 1988;Hasnain et al, 1989Hasnain et al, , 1994Hasnain et al, , 1995Al-Shalan et al, 1989) documented the occurrence of airborne fungal airspora where the presence of basidiospores were not recorded. However, in recent years, airborne basidiospores have been reported in some parts of the country (Hasnain et al, 1998;Hasnain et al, 2004).…”