Continuous subcutaneous hydrocortisone infusion in pediatric primary adrenal insufficiency: a cohort study.

Objective: Primary adrenal insufficiency (PAI) in children, most commonly caused by congenital adrenal hyperplasia (CAH), is challenging to treat due to the short half-life of hydrocortisone and the difficulty in mimicking the physiological rhythm of cortisol. Continuous subcutaneous hydrocortisone infusion (CSHI) has shown benefits in CAH adults but remains poorly studied in children. The aim of our study was to evaluate the feasibility, safety, and clinical efficacy of CSHI in pediatric patients under oral treatment with poorly controlled PAI. Methods: We conducted a retrospective monocentric study including 13 children and adolescents with PAI who were switched from oral hydrocortisone to CSHI between 2017 and 2024 due to a lack of disease control. Hormonal and clinical parameters were monitored over a median follow-up of 48 months. Results: The median age at CSHI initiation was 11.08 (7.75-14.08) years. Eleven patients (84.6%) had CAH. The median duration of CSHI was 48 (6-54) months. Biochemical control improved, morning cortisol increased, while ACTH, 17-OHP, androstenedione, and testosterone levels decreased during follow-up. Growth velocity and BMI remained stable. In one patient with prior and recurrent adrenal crises, these events ceased. In boys with testicular adrenal rest tumors, tumor volume decreased or resolved. One adolescent girl with amenorrhea resumed regular menstrual cycles under CSHI. CSHI was well tolerated with no major complications. Conclusion: CSHI offers a promising therapeutic alternative for children with PAI who are poorly controlled on oral therapy. It provides more physiological cortisol delivery, improves hormonal control, and appears safe during long-term pediatric use. Larger prospective studies are needed to confirm these findings and evaluate quality-of-life outcomes.