Aspirin Allergy and Desensitization Protocols

For patients who suffer from terrible allergies, asthma, nasal polyps, and also suffer an allergy to aspirin, desensitization to aspirin can profoundly improve overall allergies and airway hyper-reactivity through an as yet unknown mechanism. It is hypothesized that aspirin desensitization works by decreasing leukotriene production and downregulating cystienyl leukotriene receptors resulting in a decrease in histamine and tryptase release from mast cells which causes allergy symptoms.

However, there are two problems regarding patients who wish to pursue aspirin desensitization: not many physicians perform it due to risk of life-threatening anaphylaxis and lack of standardized protocols.

Here are some sample published protocols for aspirin desensitization. Keep in mind that regardless of which protocol is administered, the aspirin desensitized state only exists as long as regular aspirin continues to be taken. If the patient forgets to take aspirin for a few days (typically 48 hours), the protocol has to be repeated.

Protocol #1:
Aspirin dissolved in water at 1mg/cc concentration. On day 1, patient is given 10mg, 30mg, 60mg, and 100mg of aspirin spaced 6 hours apart. On day 2, an additional 100mg, 150mg, and 300mg is given spaced 8 hours apart. The patient is discharged home on 300mg or 350mg of aspirin to be taken twice a day as well as zantac 150mg twice a day for GI prophylaxis. If needed, proton pump inhibitors can also be taken.

Protocol #2:
Aspirin is administered at intervals of 10–30 min in the following dosages: 0.1 mg, 0.3 mg, 1 mg, 3 mg, 10 mg, 30 mg, 40 mg, 81 mg, 162 mg, and 325mg. The dilution and dosing may be altered depending on the patient's clinical situation.



Protocol #3:
Aspirin is administered starting at 1 mg and doubling each dose every 30 min up to a final dose of 100 mg (therefore lasting 3.5 hours).

Protocol #4:
Aspirin given in 5 sequential doses of 5, 10, 20, 40, and 75 mg given every 30 minutes (the protocol lasting 2.5 hours).

Depending on the physician, patient's clinical characteristics, and comfort level of all concerned, these protocols may be performed in an office-setting to even in the intensive care unit of a hospital.

Pre-treatment with anti-histamines, singulair, or systemic steroids may or may not be administered. Beta-blockers typically is stopped 24 hours prior to protocol initiation. Monitoring during the protocol include blood pressure, pulse, and peak expiratory flow measurements every 30 min as well as checking for any reactions involving the skin, nose, eye, or breathing. Once the protocol is completed, monitoring is continued for an additional 3-6 hours.

Keep in mind that our office does not perform aspirin desensitization and provides this information for educational purposes. Please contact your local allergist to determine if they perform aspirin desensitization. Your best bet is your closest tertiary care academic medical center as locations where such protocols are performed.

Trivia: When a patient suffers from asthma, nasal polyps, and aspirin allergy, it is known as Samter's triad.

The Washington Post published an article about aspirin desensitization. Read the article here!


References:
Hypersensitivity to ASA in patients with coronary artery disease: rapid desensitisation is feasible. European Society of Cardiology Council. E-journal of Cardiology Practice 3.

Selection of patients for ASA desensitization treatment. J Allergy Clin Immunol 118: 801–804.

Rapid oral challenge-desensitisation for patients with ASA-related urticariaangioedema. J Allergy Clin Immunol 105: 997–1001.

Rational approach to aspirin dosing during oral challenges and desensitization of patients with aspirin-exacerbated respiratory disease. J Allergy Clin Immunol. 2009 Feb;123(2):406-10. doi: 10.1016/j.jaci.2008.09.048. Epub 2008 Dec 3.

Selection of aspirin dosages for aspirin desensitization treatment in patients with aspirin-exacerbated respiratory disease. J Allergy Clin Immunol. 2007 Jan;119(1):157-64. Epub 2006 Nov 13.

ASA sensitivity: the role for ASA challenge and desensitisation in postmyocardial infarction patients. Cardiology 91: 8–13.

Rapid desensitisation procedure for patients with ASA hypersensitivity undergoing coronary stenting. Am J Cardiol 95: 509–510.

Aspirin Hypersensitivity and Desensitization Protocols. Ther Adv in Drug Safe. 2011;2(6):263-270.