Background Evidence of the efficacy of omalizumab for mast cell activation disease (MCAD) has been collected from only a few case series and isolated cases. It is not approved for this indication in the USA or Europe.

Purpose To describe omalizumab’s effectiveness in a patient with MCAD.

Material and methods A 40-year-old woman with MCAD syndrome had initial symptoms of hives, itching, angio-oedema, flushing, palpitations, diarrhoea, dizziness, dyspnoea and episodes of anaphylaxis. After a maximum dose of antihistamines, the patient presented with urticaria symptoms, to the same clinic, reporting constraint of her usual daily activities.

Results She had improvement in symptoms with omalizumab therapy, reducing the flushing, urticaria and tachycardias, and had better exercise tolerance. These symptoms had not improved with the maximum dose of antihistamine. For management of the disease, previous studies used the same dose of omalizumab, regardless of the levels of IgE and patient weight. The patient described generalised tingling the days prior to the next dose and in the days after administration. She continues to receive omalizumab 300 mg subcutaneously every 4 weeks, showing a good clinical response.

Conclusion This case supports the potential efficacy of omalizumab as a mast cell stabiliser for MCAS in adults not responding to maximal antihistamine therapy.

References and/or Acknowledgements To my pharmacists colleagues.

No conflict of interest.