It usually takes about 3 weeks to develop a new generation of mites. The mites are susceptible to drying and can not live more than a day or two off the host. Peuritis usually does not develop until the skin has become sensitized. Involved area usually show an accumulation of exudate from the inflammation which coagulates to form a crust. Excessive keratinazation and proliferation of connective tissue occurs resulting in thickened skin and hair loss.
Secondary infection is common.
Diagnosis is by microscopic identification of the mite that is usually obtained by scraping the skin at the outer edges of the lesions. Mineral oil or similar liquids are often used to keep skin particles confined and help confine mites and skin tissue for easier application on a microscope slide. Histologic evaluation of infested tissue reveals numerous mites in the stratum corneum. Members of this genus can be identified by the presence of sarcoptiform pretarsi with a long unsegmented caruncle. These are parasites in the skin of mammals and individuals have an anus that is terminal on the ventral side.