Sir,Polyglandular autoimmune syndromes (PAS) are constellations of symptoms and signs of multiple glandular insufficiencies. We report a very rare case of type IIIc PAS in a young female.A 32-year-old young female, P0+0, presented with fever, weakness, fatigue, dizziness, abdominal pain, nausea and vomiting for last 10 days. She was amenorrheic for last 10 years. She was diagnosed as a case of hyperthyroidism 7 years back for which she was prescribed carbimazole. She also had diabetes mellitus (DM type I) for last 3 years, for which she was taking insulin irregularly, and alopecia for last 6 months. There was no family history of similar disorder. On examination of the patient, she looked ill. She was not obese. There was diffuse loss of scalp hair, and the rest of her general and systemic examination was normal.Investigation revealed a normal hemogram with normal general blood picture. Her corrected erythrocyte sedimentation rate (ESR) was 50 mm in 1st hour; fasting and postprandial blood sugar levels were 341 mg/dL and 482 mg/dL, respectively; HbA1C was 9% and urine was positive for sugar (2 g) and ketone (moderately positive). Her liver, renal and thyroid function tests, serum electrolytes, chest X-ray and ultrasound abdomen were normal. Other laboratory investigations disclosed depressed luteinizing hormone (LH; 0.32 mIU/ml) and follicle stimulating hormone (FSH; 2.30 mIU/ml), normal serum cortisol level and positive human leukocyte antigen (HLA) DR3. She was treated with the standard protocol for diabetic ketoacidosis and broad-spectrum antibiotics to which she showed gradual response and has been doing well in follow-up.PAS form a diverse cluster of autoimmune conditions and are uncommon endocrinopathies that are typified by the occurrence of at least two glandular autoimmune mediated diseases.[1] PAS I is characterized by the classic triad of mucocutaneous candidiasis (90–100%), hypoparathyroidism (80–85%) and Addison's disease (70–75%) appearing in a chronological order. For diagnosis, at least two of the three major components need to be present. PAS II is characterized by the presence of autoimmune Addison's disease (100%) in association with either autoimmune thyroid diseases and/or type 1 diabetes. It is the most common type encountered clinically. PAS III shows a direct association of autoimmune thyroid disease (Hashimoto's thyroiditis, Grave's disease) and type 1 diabetes and is found in the absence of Addison's disease. It is a very rare condition. The exact worldwide prevalence of PAS III is unknown. It is typically observed in middle-aged women but can occur in persons of any age.[2] The hallmark of PAS III is the absence of Addision's disease. PAS type III has been further classified into three categories:[3] PAS IIIa – autoimmune thyroiditis with immune-mediated diabetes mellitus; PAS IIIb – autoimmune thyroiditis with pernicious anemia; and PAS IIIc – autoimmune thyroiditis with vitiligo and/or alopecia and/or other organ-specific autoimmune disease. PAS IV is a rare syndrome characterized by the association of autoimmune combinations not falling in the above categories, for example, Addison's disease with one or more minor components (rheumatoid arthritis, autoimmune liver disease, primary gonadal failure, pernicious anemia, celiac disease, vitiligo, etc.) excluding other major components of PAS I, II and III.[2]The combination of type 1 DM, hyperthyroidism, hypogonadism and alopecia suggests PAS type IIIc in our patient. It is mandatory to consider other glandular hypofunction while evaluating patients with any type of endocrine hypofunction because multiple glandular involvement is quite frequent. Early detection of antibodies and latent organ-specific dysfunction is advocated to alert physicians to take appropriate action in order to prevent full-blown disease.