D3.191 - Case report: Acute systemic reactions to sublingual immunotherapy for tree pollen
Case report
BACKGROUND: Sublingual immunotherapy (SLIT) is more convenient for patients and clinicians because therapy is self-administered by the patient (or caregiver) at home. With regard to the application at home, the safety of this form of immunotherapy is especially important.
CASE REPORT: A 17-year-old boy with a history of perennial allergic rhinitis and well-controlled intermittent asthma due to tree pollen came to the Clinic for the first application of SLIT with standardized extract of tree pollen (Stallergenes, France) under the supervision of an allergologist. The dose regimen was as follows: 1, 2, 4, 6, 8, 10, 30, 60, 120IR/day. The maintenance phase consisted of daily intake of a 120IR dose until the end of the tree pollen season. Before coming to the clinic, the patient took his regular asthma therapy fluticasone propionate 125 microgram. Spirometry was within normal values and boy administered first dose (1 drop, 10IR/ml) of allergen preparation. Within 10 minutes of application, he complained of feeling of thick throat, pressure in his chest and started coughing. In the clinical examination we found: blood pressure 120/90 mmHg, heart rate 120/min, oxygen saturation 96%, wheezing on lung auscultation, regular pulse. According to the World Allergy Organization (WAO) systemic allergic reaction grading system, patient had a grading score of 3. He received salbutamol and corticosteroids, and all symptoms promptly resolved. The first idea was that the asthma was not well controlled and the patient was recommended the therapy with fluticasone propionate + formoterol 125 microgram/5 microgram 2 puffs twice a day until the next visit. A week later, the patient came for re-introduction of SLIT. As premedication, an oral antihistamine was prescribed 1 hour and salbutamol 20 minutes before administration. The boy tolerated first dose (1 drop, 10IR/ml) of allergen preparation with only few self-limited local side effects (oral pruritus, throat irritation). After discharge, he continued to take SLIT at home according to the protocol with oral antihistamine as premedication until day 7, when he was advised to come foran elective administration of the higher dose in the Clinic. Within 10 minutes after administration of first drop (1 drop, 30IU/ml) he developed oral itching and swelling, throatirritation, coughing, weakness and dizziness. In the clinical examination we found: blood pressure 140/90 mmHg, heart rate 160/min, oxygen saturation 96%, wheezing on lung auscultation, regular pulse (grade 4). He received intramuscular epinephrine, salbutamol and corticosteroids. In agreement with the patient and parents, SLIT was discontinued.
CONCLUSION: In patients with asthma and adverse reactions to SLIT, monitoring is required when increasing the dose of SLIT even after good tolerance of lower doses.
