Food allergy in children and young people: diagnosis and assessment of food allergy in children and young people in primary care and community settings

National Institute for Health and Clinical Excellence

Introduction

• Food allergy is an adverse immune response to a food
• Food allergy is one of the most common allergic disorders and is recognised as a major paediatric problem in western countries. Its prevalence has increased dramatically in recent decades
• There is great variation in current practice for allergy care, and there are no agreed treatment pathways or referral criteria. Many people use alternative sources of support instead of NHS services, including non-validated tests and treatments

Key to terms

• Food allergy can be classified into IgE-mediated and non-IgE-mediated allergy
• IgE-mediated reactions are acute and often have a rapid onset
• Non-IgE-mediated reactions are generally characterised by a delayed and non-acute onset
• Mixed reactions involve a mixture of both IgE and non-IgE responses

Signs and symptoms of possible food allergy*

The skin

• IgE-mediated
  • pruritus
  • erythema
  • acute urticaria (localised or generalised)
  • acute angioedema (most commonly in the lips and face, and around the eyes)

• Non-IgE-mediated
  • pruritus
  • erythema
  • atopic eczema

The gastrointestinal system

• IgE-mediated
  • angioedema of the lips, tongue and palate
  • oral pruritus
  • nausea
  • colicky abdominal pain
  • vomiting
  • diarrhoea

• Non-IgE-mediated
  • gastro-oesophageal reflux disease
  • loose or frequent stools
  • blood and/or mucus in stools
  • abdominal pain
  • infantile colic
  • food refusal or aversion
  • constipation
  • perianal redness
  • pallor and tiredness
  • faltering growth plus one or more gastrointestinal symptoms above (with or without significant atopic eczema)

The respiratory system (usually in combination with one or more of the above symptoms and signs)

• IgE-mediated
  • upper respiratory tract symptoms—nasal itching, sneezing, rhinorrhoea or congestion (with or without conjunctivitis)
  • lower respiratory tract symptoms (cough, chest tightness, wheezing or shortness of breath)

• Non-IgE-mediated
  • lower respiratory tract symptoms (cough, chest tightness, wheezing or shortness of breath)

Other

• IgE-mediated
  • signs or symptoms of anaphylaxis or other systemic allergic reactions