Twenty five year old man, diagnosed with porphyria. No psychiatric history until 6 months prior to the first psychiatric consult, when symptomatic anxiety in reaction to suspicious about his girlfriend's fidelity occurs. Never having arisen such suspicions during the relationship's previous years. When questioned, the pacient was unable to identify a specific event that triggered the distrust, merely reporting unfounded doubts which manifested in the form of intrusive ideas, more frequent and intense when he was alone and unoccupied.

The existence of psychiatric symptomatology associated with this pathology is documented in the literature. The goal of this paper is to present a case of Otelo syndrome in a pacient with a previous diagnosis of porphyria. We aim to show the patient's psychiatric symptoms’ evolution after the diagnosis and pharmacological and psychotherapeutic treatment, discussing the therapeutic difficulties determined by clinical co-morbidity.