House dust is one of the major causes of perennial allergic rhinitis (symptoms such as; runny or stuffy nose, itchy, watery eyes and sneezing), causing allergy symptoms all year round and can make sufferers of asthma experience coughing, wheezing and shortness of breath.
Because household dust is so light it becomes airborne meaning that even in clean homes allergy is common.
The content of house dust will vary from home to home and is influenced by the type of furniture, building materials, presence of pets, moisture and other factors.
A speck of dust may contain fabric fibers, human skin particles, microscopic creatures called mites, animal dander bacteria, mould spores, food particles and other debris. Of these house dust mites and animal dander (see animals) are the most common components.
A person may be allergic to one or more of these substances, and, if exposed to the dust, will have an allergic reaction.