Factitious disorder, commonly called Munchhausen’s syndrome, is a rare disorder that lacks evidence-based guidelines. Reporting clinical cases is important for sharing clinical experiences and treatment strategies. The symptoms and progression of the following case have not been previously reported in the literature. Here, we report a case involving a 41-year-old Caucasian with a suspected psychosomatic disorder. After intensive multi-professional diagnostics, we concluded that the patient had factitious disorder. The symptoms in this case changed rapidly during treatment, which posed a challenge. For factitious disorder, establishing interdisciplinary exchange is important. Symptoms that are normally treated by internists are most commonly described in the literature. This case demonstrates that psychiatrists are challenged by this diagnosis and should consider the possibility of factitious disorder when seeing patients diagnosed with somatoform disorders. The most important clinical conclusion was the importance of involving the patients’ relatives in the treatment of patients with factitious disorder.