Anaphylactic Reaction to Omalizumab (Xolair) in a Patient with Severe Asthma

Author: V. Dimov, M.D., Allergist/Immunologist and Assistant Professor at University of Chicago
Reviewer: S. Randhawa, M.D., Allergist/Immunologist and Assistant Professor at LSU (Shreveport) Department of Allergy and Immunology

A 38-year-old Caucasian male who is followed by our clinic for severe asthma and allergic rhinitis is here for his regular Omalizumab (Xolair) injection. He has been on Xolair twice a month for the last 18 months and tolerated it well until 2 weeks ago when he reported mild shortness of breath 15 minutes after the injections. The spirometry was at his baseline at that time.

Past medical history (PMH)

Asthma, allergic rhinitis, obesity, obstructive sleep apnea (OSA).

Medications

Advair, prednisone 7 mg po qod, Singulair, Flonase, loratidine, Combivent prn.

What happened?

The patient received a Xolair (omalizumab) injection today at 8:40 a.m. He was observed at the clinic for 30 minutes and after that, he drove home. At 10:00 a.m., he felt itchy all over his body, and 20 minutes later, he developed aperiorbital swelling and urticarial rash around his left eye with increased pruritus.

The patients called out clinic and was advised to take prednisone 40 mg po x 1 and Benadryl 25 mg po x 1. His itching began to resolve, the swelling and the urticarial rash also started to disappear. His wife drove him back to the clinic and he felt slightly dizzy.

Physical examination

Stable vital signs (VSS).
Skin: faint periorbital urticaria and mild edema around the left eye.
Ears: Clear.
Nose: Pale, boggy turbinates.
Respiratory system: Clear to auscultation bilaterally. No wheezing or crackles.
Cardiovascular system: Clear S1, S2.
Gastrointestinal system: Normal bowel sounds, soft, non-tender, non-distended.
Extremities: No edema or rash.

What is the most likely diagnosis?

Anaphylactic reaction to Xolair (omalizumab) represented by the skin reaction described above.

What would you do?

His vital signs are stable and he has no other signs of anaphylaxis. The skin reaction has almost completely disappeared after he took prednisone and Benadryl.

We decided to discontinue Xolair at this point and to continue prednisone 40 mg po daily for two days, then change the prednisone dose to his maintenance regimen.

What happened next?

The skin lesions resolved completely and the patient was advised to go home and to call with any questions or concerns. The followed in our clinic a week later and had no further complaints.

Final diagnosis

Anaphylactic Reaction to Omalizumab (Xolair) in a Patient with Severe Asthma.

What did we learn from this case?

Asthma is the most common chronic respiratory disease, affecting up to 10% of adults and 30% of children (JACI, 2011).

The AAAAI/ACAAI Joint Task Force concluded that 39,510 patients received Xolair (omalizumab) between 2003 and 2005. From this group, 35 patients had 41 episodes of anaphylaxis related to Xolair. Calculated anaphylaxis-reporting rate was 0.09% of patients, 61% of reactions occurred in the first 2 hours after one of the first 3 doses. Omalizumab binds to Cε3 region of IgE.

An observation period of 2 hours for the first 3 injections and 30 minutes for subsequent injections would have captured 75% of the anaphylactic reactions.

References

American Academy of Allergy, Asthma & Immunology/American College of Allergy, Asthma and Immunology Joint Task Force Report on omalizumab-associated anaphylaxis. Cox L, Platts-Mills TA, Finegold I, Schwartz LB, Simons FE, Wallace DV. J Allergy Clin Immunol. 2007 Dec;120(6):1373-7. Epub 2007 Nov 9.
Delayed allergic reactions to omalizumab: Are patients reporting all cases? JACI, 03/2008.

Anaphylaxis guidelines by World Allergy Organization. JACI, 2011.
Images: Mechanisms of action of omalizumab. JACI, 02/2008.

Published: 12/23/2008
Updated: 03/23//2011