Longitudinal profiles of serum specific IgE and IgG4 to Dermatophagoides pteronyssinus allergen and its major components during allergen immunotherapy in a cohort of southern Chinese children.

•Allergy immunotherapy (AIT) is the only treatment that offers disease-modifying effects.•Der p 1 sIgE/sIgG4 ratio is useful to monitor HDM atopy during AIT.•Younger children may have greater increase in protective sIgG4.•AIT given earlier may result in better therapeutic outcomes than later.