Differential Diagnosis for Autoimmune Conditions Causing Recurrent Passing Out

• Single Most Likely Diagnosis

  • Postural Orthostatic Tachycardia Syndrome (POTS): This condition is characterized by a rapid increase in heart rate and other symptoms that occur upon standing, which can lead to recurrent passing out. It is often associated with autoimmune disorders and can be triggered by various factors, including autoimmune conditions.

• Other Likely Diagnoses

  • Dysautonomia: A disorder of the autonomic nervous system that can cause a range of symptoms, including orthostatic intolerance, which may lead to passing out. It can be associated with autoimmune conditions.
  • Autoimmune Autonomic Ganglionopathy: A rare autoimmune disorder that affects the autonomic nervous system, leading to symptoms such as orthostatic intolerance and potentially causing recurrent passing out.
  • Systemic Lupus Erythematosus (SLE): A chronic autoimmune disease that can affect various parts of the body, including the nervous system, and may cause symptoms like passing out due to its effects on blood pressure regulation and the autonomic nervous system.

• Do Not Miss Diagnoses

  • Multiple System Atrophy (MSA): A neurodegenerative disorder that can present with autonomic dysfunction, including orthostatic hypotension, which may cause passing out. Although not strictly an autoimmune condition, its presentation can mimic autoimmune disorders, and missing this diagnosis could be critical due to its progressive nature.
  • Addison's Disease: An autoimmune condition where the adrenal glands are damaged, leading to a deficiency of cortisol and aldosterone. This can cause hypotension, leading to passing out, and is critical to diagnose due to the potential for adrenal crisis.

• Rare Diagnoses

  • Autoimmune Hypoparathyroidism: A condition where the immune system attacks the parathyroid glands, potentially leading to hypocalcemia, which can cause muscle cramps, tetany, and possibly lead to passing out due to its effects on the nervous system.
  • Stiff Person Syndrome: A rare autoimmune disorder that affects the nervous system, leading to progressive stiffness and rigidity of the muscles, which can potentially cause falls or passing out due to loss of muscle control.