What is Cladosporium?

Cladosporium is the genera most frequently encountered in both outdoor and indoor air. It is found in elevated levels in water-damaged environments. Some species may be resistant to certain types of treated lumber. Cladosporium appears gray to black or very dark green and can have a powdery appearance. The genus Cladosporium includes over 30 species. The most common ones include Cladosporium elatum, Cladosporium herbarum, Cladosporium sphaerospermum, and Cladosporium cladosporioides.

Cladosporium is a dematiaceous (pigmented) mold widely distributed in air and rotten organic material and frequently isolated as a contaminant on foods. Some species are predominant in tropical and subtropical regions . Also, some Cladosporium spp. were isolated from fish and were associated with findings of infection. Cladosporium is a common fungus that is a known and documented aero-allergen which is usually associated with plants, wood products, and leather goods; the spores are easily made airborne and as such are a common cause of respiratory problems; allergic reactions and can be an agent for hypersensitivity diseases; it is as a parasite in infections of the skin, soft tissues or nails and has been documented in cases of Blastomycosis, Candidiasis, Chromoblastomycosis, Histoplasmosis, Entomophthoramycocis, Phaeophphomycocis and Keratomycosis.

The findings suggest that fungal antigens from species found in homes are commonly associated with skin sensitization in an allergy clinic population with upper or lower respiratory allergy. No specific relationships were found, however, between the prevalence of fungal species in the home environment and the prevalence as skin-test allergens.

Most commonly identified outdoor fungus. The outdoor numbers are reduced in the winter. The numbers are often high in the summer. Often found indoors in numbers less than outdoor numbers. Indoor Cladosporium may be different than the species identified outdoors. It is commonly found on the surface of fiberglass duct liner in the interior of supply ducts. A wide variety of plants are food sources for this fungus. It is found on dead plants, woody plants, food, straw, soil, paint and textiles. Produces greater than 10 antigens. Antigens in commercial extracts are of variable quality and may degrade within weeks of preparation.

Sick Building Syndrome

Sick Building Syndrome (SBS) is a term commonly used for non-specific symptoms that are temporally related to occupancy of a particular building. When building-related symptoms are characteristic of a specific clinical entity, they are called Building Related Illness (BRI). These illnesses are varied, and include Legionnaires’ disease, building related hypersensitivity pneumonitis, building-related asthma, and others.

SBS symptoms include mucous membrane irritation (cough, scratchy throat, stuffy sinuses, and itchy eyes), headache, fatigue, difficulty concentrating, and other non-specific symptoms. The causes of SBS vary with the building and its occupants. SBS was once called “Tight Building Syndrome” and was considered to be a result of excess tightening of buildings in response to energy use concerns. However, many buildings with an excess of symptoms among the occupants are well ventilated. Still, increase in ventilation rates is often the “cure” for the problem.

Some people consider that SBS is caused not by the physical environment, but, rather, by psychosocial factors. Gender, lack of control, poor management, too much work, too little work, perceived housekeeping quality, and many other social factors have been blamed for the symptoms. In some cases, psychosocial factors may be the major cause of complaints. However, clearly, in some cases, environmental factors are at fault. For example, paper dust, and photocopier use have both been related to increases in complaints in a dose-dependent way. An excess of volatile organic compounds have been blamed for SBS symptoms. However, one study attributed this effect to the perception of odors at VOC concentrations far below those that would be likely to have an effect. These authors discuss the possibility that reactive chemistry might produce irritants that might be responsible for some symptoms.

Mold contamination has clearly been related to cases of BRI. However, its relationship to SBS is less clear. A Swedish study documented that dampness in residential buildings was associated with SBS symptoms with symptoms increasing with the number of dampness indicators present. Whether or not mold growth was responsible for these symptoms remains unknown. An extremely interesting study exposed people to measured doses of airborne fungal spores from growth on building materials. In this study, symptoms were similar among the two fungi studied AND for the placebo tests, indicating no specific effect of the spores. Mycotoxins have not been measured in quantities sufficient to cause the normal SBS symptoms, and the data regarding the role of mycotoxins in indoor air remain equivocal.