This document discusses psychocutaneous diseases, which involve interactions between psychological factors and skin conditions. These are grouped into four categories: primary psychiatric disorders involving self-induced skin findings; secondary psychiatric disorders caused by skin diseases; psychogenic pruritus without evidence of skin disease or medical condition; and psychophysiological disorders where skin conditions are exacerbated by emotions. Specific conditions discussed include delusional skin disorders like delusions of parasitosis where patients believe their skin is infested without evidence. Diagnosis involves evaluating duration, functioning, relation to other conditions, and treatment typically involves antipsychotic medication and psychiatric therapy.