This report focuses on the progressive manifestations of PANS and PANDAS in adults, extending beyond the primary identification of these conditions in children. It describes the clinical features, pathophysiological mechanisms, diagnostic considerations, and therapeutic approaches for both syndromes, which are characterized by the acute onset or exacerbation of neuropsychiatric symptoms, often associated with an immunological trigger. A case report illustrates how a patient’s PANDAS symptoms intensify as an “immune signal,” even before the visible onset of an infection. The authors emphasize the need for further research on these adult manifestations, particularly outside the USA and Asia, to gain a deeper understanding of the underlying mechanisms.