BACKGROUND: In insulin treatment for type 1 diabetes, intermittent scanning continuous glucose monitoring (isCGM: FreeStyle® Libre), in which a sensor is adhered to the skin, is often used to monitor blood glucose fluctuations and manage glucose levels. Zinc-deficient skin is reportedly more susceptible to primary irritant rashes. This study investigated whether zinc deficiency is associated with a history of contact dermatitis caused by isCGM in patients with type 1 diabetes. METHODS: The subjects comprised 55 patients (23 men, 32 women, age 57.9 ± 17.6 years) with type 1 diabetes who were outpatients at our department and had a history of isCGM use. We examined the history of contact dermatitis due to isCGM in relation to serum zinc concentration. RESULTS: Serum zinc was significantly lower in those with history of contact dermatitis (23 subjects) compared to those without (32 subjects) (P = 0.033). History of contact dermatitis due to isCGM was negatively associated with both age (β = - 0.266, P = 0.040) and zinc deficiency category (β = - 0.315, P = 0.017). CONCLUSIONS: For people undergoing treatment for type 1 diabetes for whom skin problems caused by isCGM are a barrier to glucose management, screening of serum zinc concentration may be important.