Autonomic dysfunction arises from dysregulation of the autonomic nervous system, which governs vital functions like cardiovascular stability, gastrointestinal motility, and thermoregulation. Symptoms include orthostatic hypotension, gastroparesis, and cardiac arrhythmias. Conditions like Guillain-Barré syndrome (GBS) and autoimmune small fiber neuropathy are known causes, with autonomic involvement in up to 65% of GBS cases.

This case highlights the complexities of diagnosing autonomic dysfunction. Autonomic GBS was considered, but due to lack of areflexia and normal EMG findings, Acute Sensory and Autonomic Neuronopathy (ASANN) was more likely. ASANN features acute sensory loss and autonomic dysfunction, affecting urinary, cardiovascular, and gastrointestinal systems. ASANN is rarely reported, with limited cases since its 1980 description. Although immunomodulatory therapies can slow progression, treatment response is limited.

In this patient, co-occurrence of IgA nephropathy and ASANN was likely the result of post-infectious immune dysregulation. Although there are no previous reports of co-occurrence of the two auto-immune disorders, Chlamydia Trachomatis is known to cause autoimmunity via molecular mimicry mechanisms.