What is APS-2?

APS-2 (Schmidt Syndrome) is the most common autoimmune polyglandular syndrome, characterized by Addison's disease (adrenal insufficiency) combined with either autoimmune thyroid disease and/or type 1 diabetes. It typically presents in adulthood.

Diagnostic Criteria (Must Have Addison's + At Least One Other):

• Addison's Disease (100% - Required): Primary adrenal insufficiency
• PLUS one or both of:
  • Autoimmune Thyroid Disease (70-80%): Hashimoto's thyroiditis or Graves' disease
  • Type 1 Diabetes (30-50%)

Other Associated Conditions:

• Primary Hypogonadism
• Celiac Disease (common)
• Pernicious Anemia
• Vitiligo (10-20%)
• Myasthenia Gravis
• Alopecia Areata

Key Differ ences from APS-1:

• Age of Onset: Adulthood (20s-40s) vs. childhood (APS-1)
• Genetics: Polygenic/HLA-associated vs. single gene (AIRE) in APS-1
• More Common: 1-2 per 100,000 vs. very rare APS-1
• NO Candidiasis or Hypoparathyroidism (unlike APS-1)
• Female Predominance: 3:1 female:male ratio

Diagnosis & Management:

• Screen for Other Autoimmune Diseases: Once one is diagnosed
• Annual Surveillance: TSH, fasting glucose, celiac screening
• Hormone Replacement:
  • Hydrocortisone (for Addison's)
  • Levothyroxine (if hypothyroid)
  • Insulin (if diabetic)
• Emergency Precautions: Steroid emergency card, stress dosing education
• Family Screening: Siblings have increased risk