It takes at least three months to see effects, so a three month trial of ASA desensitization is recommended to assess whether this intervention has been helpful and whether it should be continued.
Aspirin treatment is lifelong, since interruptions in treatment are associated with loss of tolerance. Having said that, situations may arise that warrant discontinuation of ASA, such as gastric irritation, pregnancy and elective surgery.
Waldram JD and Simon RA. Performing aspirin desensitization in aspirin-exacerbated respiratory disease. Immunol Allergy Clin N America 2016; 6(4):693-703.
I hope this information is helpful to you and your patient.
Jacqueline A. Pongracic, MD, FAAAAI