Long‐term follow‐up of de novo allergy in pediatric liver transplantation – 10 yr experience of a single center

We conducted a study to clarify the incidence, clinical course, and risk factors of de novo allergies after liver transplantation. Ninety‐three patients who had been followed longer than one yr and who had no previous allergy history were included. Forty‐two patients (45.2%) developed de novo allergy. Of them, food allergy developed in 35 (37.6%). Respiratory allergy was observed in three (3.2%), and a patient (1.1%) had drug allergy. Fifty‐two (55.9%) of the 93 patients developed eosinophilia. The median age of patients with de novo allergy was 15 months (IR 11.3–20 months). De novo allergy developed five months after liver transplantation (IR 2.3–9.5 months) and lasted for 16 months (IR 8–34.5 months). Younger age at liver transplantation displayed statistically significant differences in development of allergy between allergy and non‐allergy groups. Twenty‐nine (69.0%) patients improved from allergy during the follow‐up period. No patient with de novo gastrointestinal allergy progressed to any respiratory allergy such as asthma. Older age at transplantation, EBV non‐risk, and CMV non‐risk had statistical significance in allergy improvement. Younger age at transplant predisposes to the development of allergy, while improvement of allergy is achieved more in older age.