Factitious disorder imposed on another (FDIA), formerly known as Munchausen syndrome by proxy (MSBP), constitutes a form of child abuse wherein a caregiver fabricates or induces illness in a person under their care or supervision. Here, we present a case of a two-year-old girl with signs and symptoms suggestive of undifferentiated connective tissue disease (UCTD) and probable autoinflammatory disease, which was a manifestation of FDIA. The patient manifested recurrent febrile episodes and presented with hepatosplenomegaly, elevated inflammatory markers, and mesangial proliferative glomerulonephritis. Regardless of extensive medical interventions, including corticosteroids and immunosuppressive therapy, the patient's condition failed to improve until the caregiver was isolated from the patient. Upon questioning, the caregiver admitted to having administered pyrogenal, an immunomodulator, to induce symptoms. This case highlights the challenges and difficulties of diagnosing and managing FDIA-associated illnesses, drawing attention to the importance of considering this diagnosis in cases of unexplained or recurrent fever in children.