Allergy skin prick testing can be performed from infancy, and there is no minimum age below which it is not appropriate when a clinical question about allergy needs to be answered. In practice I typically begin allergy testing from around 12 to 18 months in infants with persistent eczema or suspected food allergy, and from 2 to 3 years in children with recurrent nasal or respiratory symptoms. Skin prick testing uses a small standardised lancet to place a tiny droplet of allergen extract onto the forearm skin - the lancet barely penetrates the surface of the skin and most children experience it as a mild scratch rather than a sharp pain. Results are read at 15 to 20 minutes, giving immediate answers in the clinic rather than requiring a return visit. For children who cannot stop antihistamines or who are too young to cooperate with skin testing, specific IgE blood testing provides equivalent information from a single blood draw. The most important thing parents need to understand is that a positive allergy test result identifies immune sensitisation - it does not by itself confirm that the allergen is causing the child's symptoms. The result is always interpreted alongside the child's clinical history to determine which sensitisations are clinically relevant.
Written by Dr. Bharat Mehra, MBBS, MD Paediatrics, FPECC (Fellowship in Paediatric Emergency and Critical Care), IFPCCM (Indian Fellowship in Paediatric Critical Care Medicine), DPAA (Diploma in Paediatric Allergy and Asthma), AAAIC (Advanced Allergy and Asthma in Clinical Immunology), Consultant Paediatrician, Paediatric Intensivist and Allergy Specialist, Bangalore. Phone: +91 9999538720.
