There is a clear overlap of symptoms with the different types of food hypersensitivities so it is important that families obtain the correct diagnosis to ensure the most appropriate treatment options. Where these symptoms are identified for the first time in the pharmacy they should be referred to the GP to initiate diagnostic procedures.

The diagnosis of food allergies and intolerances involves a detailed clinical history and medical examination, followed by skin-prick or specific IgE tests or patch tests in IgE-mediated cases. This in itself is not considered 100% reliable so it should be followed by a period of elimination and re-introduction of the offending food(s). Avoidance of known allergens is currently the only way to prevent adverse reactions but it is also very important to maintain a nutritionally complete diet. Children with confirmed food allergies and intolerances require the support and advice of a dietitian. But where parents have been advised to make dietary changes, there will be a need for reinforcement of this advice, which can be provided by the pharmacy team.

Where breastfed infants show signs of CMPA the mother should be encouraged to maintain breast-feeding but to eliminate dairy products from her own diet, thereby preventing the allergen appearing in the breastmilk. Good advice on maintaining a healthy diet in the absence of dairy products and the use of calcium, vitamin D and other supplements should be given.

Advice for formula-fed infants

• Foods for special medical purposes should only be used under medical supervision.
• Extensively hydrolysed formulae are recommended as first line in mild to moderate CMPA. Here, the milk protein is broken down into smaller, less allergenic molecules.
• In severe cases an amino acid (elemental) formula should be used where there is no protein present and instead free amino acids are used. These are considered nonallergenic.
• Soya based formulae are not recommended for infants under six months due to the presence of phytoestrogens.
• Soya based milks can lead to symptoms of soya protein allergy and infants who are allergic to cow's milk often react to soya protein.
• Soya may be appropriate where cultural or religious considerations apply or where palatability is an issue.
• Palatability of specialist formula may be an issue in infants over six months. Whey based formulae are more palatable.
• Other mammalian milks, such as goat, sheep and buffalo, are not recommended in infants since they are not nutritionally adequate and have a similar protein structure to cow's milk and so are still likely to cause allergic symptoms.
• Where a suitable formula is found it should be used as a drink and in food preparation.
• The majority of infants grow out of CMPA by the age of one to three years.