Efficacy of Starting Very-Low-Dose Cow's Milk Intake in Children Aged 1-12 Years With Severe Cow's Milk Allergy: A Retrospective Study.

PURPOSE: To avoid the complete elimination of cow's milk (CM) from the diet, we introduced a very-low-dose (VLD) oral food challenge (OFC) as part of an OFC-based stepwise ingestion protocol in patients with severe CM allergy in 2019, when the OFC protocol at our center was revised. This study investigated the efficacy of initiating CM intake through an OFC-based stepwise ingestion protocol starting from a VLD in achieving a negative full-dose OFC.

METHODS

Patients with a history of overt allergic reactions to low-dose (LD; 3 mL CM: 100 mg CM protein) CM or lesser within 6 months and those with complete CM elimination were included. We retrospectively compared the rate of passing a full-dose OFC (200 mL CM: 6,600 mg CM protein) between patients who underwent an LD OFC before 2019 (LD group) and those who underwent a VLD OFC (0.3 mL CM: 10 mg CM protein) after 2019 (VLD group). The period for passing the full-dose OFC was evaluated using Kaplan-Meier survival analyses.

RESULTS

We allocated 270 and 267 patients into the LD and VLD groups, respectively. The median age at initiation of the OFC-based stepwise ingestion protocol was 3.6 (2.3-5.4) and 3.4 (2.0-5.1) years in the LD and VLD groups, respectively. The LD and VLD groups had CM-specific immunoglobulin E levels of 21.9 (10.9-44.0) kUA/L and 20.5 (9.0-47.2) kUA/L, respectively. The baseline clinical characteristics of the two groups showed no significant differences in background. Over 4 years, the LD and VLD groups passed the full-dose OFC at rates of 45% and 60%, respectively, with a significant difference (log-rank test, P = 0.023).

CONCLUSIONS

Initiating CM intake through an OFC-based stepwise ingestion protocol starting from a VLD may contribute to achieving a negative full-dose OFC in patients with severe CM allergies.