Sinusitis is an inflammation of the nasal sinuses, which are hollow cavities within the bones found around and behind the nose. The inflammation is usually caused by inadequate draining of the sinuses due to allergy, infection or obstruction. There are two types of sinusitis. The first is acute sinusitis, which is caused by bacterial infection in most cases, and usually occurs as a late complication of a common cold. The second type is chronic sinusitis, which may be caused by bacterial infection, but more often is a chronic inflammatory disorder similar to bronchial asthma.
Immunologic problems are another possible cause of chronic sinusitis.
Hypersensitivity pneumonitis is caused by exposure to various organic dusts, such as bird droppings, contaminated grain and feathers. Symptoms include fever, wheezing, chills and shortness of breath. Itching, sometimes intense, can lead to scabbing and flaking lesions. If bacterial or viral infection is introduced by scratching, the affected lesions ooze. Hives are red, very itchy, swollen areas of the skin, often appearing in clusters.