What are the key clinical features to consider when diagnosing a food allergy in children?

Key clinical features to consider when diagnosing a food allergy in children include:

• Personal or family history of atopic diseases such as asthma, eczema, or allergic rhinitis, or known food allergies in parents or siblings.
• Details of foods avoided and reasons for avoidance.
• Assessment of presenting symptoms including the age at symptom onset, speed and reproducibility of symptoms after food exposure, severity, duration, frequency, and setting of reactions.
• Symptoms involving multiple organ systems, especially persistent symptoms.
• Signs and symptoms consistent with IgE-mediated allergy such as acute urticaria, angioedema (commonly lips, face, eyes), pruritus, erythema, oral pruritus, nausea, vomiting, abdominal pain, and respiratory symptoms like wheezing or shortness of breath.
• Signs and symptoms consistent with non-IgE-mediated allergy including atopic eczema, gastro-oesophageal reflux, loose stools, blood or mucus in stools, food refusal, constipation, perianal redness, pallor, tiredness, and faltering growth combined with gastrointestinal symptoms.
• Signs of anaphylaxis or systemic allergic reactions.
• Failure to respond to treatment for atopic eczema, gastro-oesophageal reflux disease, or chronic gastrointestinal symptoms.
• Physical examination findings such as growth parameters and signs of malnutrition or allergy-related comorbidities.

These features should be elicited through an allergy-focused clinical history and physical examination by a healthcare professional with appropriate competencies before considering allergy testing or referral to specialist care NICE CG116,NICE CKS,NICE CKS.