There is ongoing research on the health effects related to mold exposure. Molds produce allergens (substances that can cause allergic reactions) and irritants. Allergic reactions to mold are common. They can be immediate or delayed. Responses include hay fever-type symptoms, such as sneezing, runny nose, red eyes, and skin rash.Molds can also cause asthma attacks in people with asthma who are allergic to mold. Also, mold exposure can irritate the eyes, skin, nose, throat, and lungs of both mold-allergic and non-allergic people.