Endocrine Abstracts

Introduction: U-300 insulin glargine has been used as a concentrated form of glargine. Skin and subcutaneous tissue disorders (eg, rash, pruritus, and urticaria) have been reported with insulin glargine. But to our knowledge, maculopapular rash has not been reported with use of U-300 insulin glargine. We present a patient with type 1 diabetes mellitus(DM) developing maculopapular rash after initiation of U-300 glargine insulin.

Case Report: 37 year-old female patient followed up with type 1 DM for 8 years was referred to our clinics with the signs of hypoglycemia including intermittent palpitation, sweating and tremor. She had neuropathic complaints as “stocking glove” paresthesia. She had been taking multiple daily insulin injection (3*10 unit regular, 1*12 unit U-100 glargine insulin). On physical examination; vital signs were stable and systemic examination was unremarkable. Serum biochemistry and hormonal analysis revealed as fasting blood glucose(FBG) (159 mg/dL), postprandial blood glucose(PPBG) (231 mg/dL), HbA1c (6.6%), C-peptide (<0.10 ng/mL), creatinine (0.65 mg/dL), ALT (12U/L), Na (136 mmol/L), K (4.27 mmol/L), TSH (1.28 IU/mL) and free T4 (0.79 ng/mL). Due to frequent hypoglycemic attacks, the patient was accepted as “Brittle diabetes”. Insulin dosage was titrated according to monitorization of blood glucose. However, due to persistent increased morning fasting glucose levels, U-100 insulin glargine was increased to a dose of 22 unit. Nocturnal hypoglycemia occured after this adjustment; therefore, U-300 insulin glargine was initiated instead of U-100 insulin glargine. The frequency of nocturnal and daytime hypoglycemia, and glycemic variability decreased, and glycemic regulation was maintained with U-300 insulin glargine of 9 units. 3 weeks later, we detected maculopapular rash on her anterior chest, left arm and deltoid (Photograph-1). Then, U-300 insulin glargine was cessated, and rash was regressed.

Conclusion: We report a case with maculopapular rash developed in a diabetic patient after initiation of U-300 insulin glargine for a first time. Timely cessation of U-300 insulin glargine was resulted in resolution of the rash. Our case highlights rare and lesser known side effect of U-300 insulin glargine.