Delusional disorders (DDs) in dermatovenerology are not limited to delusional Infestation (DI), i.e. the rigidly held believe that a subject is infested despite a lack of medical evidence for an infestation. There is a variety of DDs of somatic type that may be related to the skin. The later may include delusional olfactory reference syndrome (the belief that the skin emits a foul odour due to medically undetected metabolism or skin changes), delusional body dysmorphic disorder (the belief that skin itself or its appendages are abnormally misshaped or ugly) or illness delusions, e.g. AIDS-delusions, syphilis delusions (the belief that the individual has an undiagnosed sexually transmitted infection – STI). Though clinical presentations of DDs in dermatovenerology are well known, there is still lack of knowledge about biological markers (e.g. MRI markers) related to different DDs subtypes. The objective of the presentation is to provide some preliminary data about as common, as distinguishing MRI markers of DI vs STI delusion in DD based on results of an original research project. Clinical significance of the findings and relations of the MRI findings to the DDs clinical signs are going to be discussed.