Background Food allergic reactions mediated by IgE are usually treated by restricting the implicated food, and in recent years desensitisation or oral tolerance induction is performed. Omalizumab is a humanised monoclonal antibody derived from recombinant DNA that selectively binds IgE. This is authorised by the European Medicines Agency (EMA) for asthma convincingly mediated by IgE and for chronic spontaneous urticaria.

Purpose To evaluate the treatment of atopic syndrome related to cow’s milk protein allergy by a combined desensitisation regimen with omalizumab.

Material and methods A child diagnosed with cow’s milk protein allergy and with non-allergic hypersensitivity (intolerance) to fructose and to veal meat. After 4 years (February 2010), his physician decided to start a desensitisation regimen to cow’s milk protein but this procedure was stopped because it was not well tolerated and the patient showed signs of allergy. Thereafter (November 2011), the physician prescribed a new desensitisation regimen and additionally omalizumab 150 mg every 4 weeks as adjuvant treatment.

The pharmacy service carried out a review of the literature to analyse the available evidence on the use of omalizumab in food allergies mediated by IgE, to assess the adequacy of the clinical condition of the patient, to analyse alternative approved indications and to estimate the economic impact. After that, we requested its use as an off-label medication.

Results After 16 months of the desensitisation-omalizumab combined treatment (until February 2013), milk tolerance to 120 mL twice a day was achieved. However, the treatment was stopped because in the past few months the patient suffered symptoms consistent with eosinophilic oesophagitis (coughing and difficulty swallowing solid foods). He underwent an endoscopic study after which the diagnosis was confirmed by increased eosinophils in the oesophageal mucosa (eosinophils are not present in healthy oesophagus).

Oesophagitis was resolved after a year on a milk free diet, but the patient occasionally describes the feeling of choking or cough after swallowing. Currently he is asymptomatic and does not take any medication.

Conclusion Omalizumab may be effective in combination with desensitisation for children with food allergies. Many patients with food allergies and atopic symdrome can develop eosinophilic oesophagitis, making treatment difficult.

No conflict of interest.