Autoimmune Diseases like Pemphigus cause patchy hair loss and scaling as the immune system attacks the body's own cells. (lowchensaustralia.com)
(27 - 29) If the scalp is involved, this is called Alopecia Areata with patchy hair loss caused by auto - antibodies reacting with the hair follicles. (bioidenticalhormones101.com)
Ringworm and yeast can infect the skin around the tail and cause intense itching without leaving outward signs such as patchy hair loss. (1800petmeds.com)