THE THREE MAJOR MOLD GROUPS: Molds are organized into three groups according to human responses; Allergenic, Pathogenic, and Toxigenic. Allergenic Molds Allergenic molds do not usually produce life-threatening health effects and primarily affect those who are already allergic or asthmatic. The human system responses to allergenic molds tend to be relatively mild depending on individual sensitivities. Typical symptoms include scratchy throats, eye and nose irritations and rashes. Pathogenic Molds Pathogenic molds usually produce some type of infection. They can cause serious health effects in persons with suppressed immune systems. Healthy people can usually resist infection by these organisms regardless of dose. In some cases, high exposure may cause hypersensitivity pneumonitis (an acute response to exposure to an organism). Toxigenic Molds Mycotoxins can cause serious health effects in almost anybody. These agents have toxic effects ranging from short-term irritation to immunosuppression and possibly cancer. Therefore, when toxigenic molds are found further evaluation is recommended.