The mites are highly contagious and the disease is worse in very young animals. Severe infestations may occur in pet shops. Indirect transmission may be as important as direct transmission. Transient parasitism of man may occur. The mites are not able to reproduce on human skin therefore constant contact with affected animals is needed to maintain human infestation.
People develop a pruritic maculo-papular dermatitis.
Pustules and crusts follow due to excoriation. Lesions are more common on arms and trunk. Pruritus seems to be due to a state of hypersensitivity and to mechanical irritation by the mites. The distribution of lesions is usually dorsal, truncal. Puppies are usually presented with lesions on the lumbosacral area that spread along the back.