Proactive risk stratification and low-risk penicillin allergy delabeling by an antimicrobial stewardship pharmacist.

Penicillin (PCN) allergy delabeling is an important component of antimicrobial stewardship; however, widespread implementation has lagged. We found that most patients had low-risk PCN allergy histories eligible for delabeling without skin testing. Pharmacist-led risk stratification and drug challenge expanded access to delabeling independently from an Allergy/Immunology service.

Safety of multiple aeroallergen rush immunotherapy using a modified schedule.

Rush immunotherapy (RIT) accelerates the build-up phase of traditional IT. The biggest potential benefit of using RIT is decreased time to symptomatic improvement. However, aeroallergen RIT carries an increased risk of systemic reaction (SR) compared with traditional IT. This study was designed to assess the safety of a modified 1-day multiple aeroallergen RIT protocol. A retrospective chart review was performed of 138 patients from an outpatient, university-based allergy practice who underwent RIT between November 2007 and February 2011. The RIT protocol consisted of eight injections over 5 hours, and stopped at one 10-fold dilution below the maintenance vial. All patients were premedicated on the same day of RIT with prednisone and histamine 1 and 2 receptor blockers. Primary end point observed was rate of SR. One hundred thirty-eight patients received a total of 2911 RIT injections. Thirty- eight patients (28%) had SRs. The SR rate per injection was 1.3%. Most of the reactions (82%) occurred after the last dose of the protocol. No patients with SR had severe anaphylaxis requiring emergency department support or hospitalization. The post-RIT SR rate was within the range seen with traditional IT. Well-controlled asthmatic patients were not at increased risk of SR compared with nonasthmatic patients. Modification of RIT to end at one 10-fold dilution below the maintenance vial for multiple aeroallergen RIT did not significantly decrease the SR rate compared with other protocols that end at the maintenance vial. Unlike hymenoptera RIT, aeroallergen RIT continues to be associated with a high risk of SR compared with traditional IT.

The spectrum and treatment of angioedema.

Angioedema manifests as episodes of localized swelling in the dermis and submucosa. The key to successful management is detection and avoidance of triggers, early recognition of attacks, and aggressive airway management when warranted. Review of a patient's medication list may identify drugs that include angiotensin-converting enzyme inhibitor or angiotensin receptor blockers as the cause. Initial treatment in a patient presenting with most forms of angioedema includes antihistamines and glucocorticoids if required. Epinephrine should be administered if there is concern for laryngeal edema. Patients who have a known history of hereditary angioedema should receive C1 esterase inhibitor concentrate or fresh-frozen plasma.

Use of olopatadine ophthalmic solution and reactivity of histamine skin testing.

The significant morbidity of allergic rhinitis and allergic conjunctivitis necessitates that diagnosis must be as accurate as possible. However, the very drugs used to treat allergic symptoms have been found to suppress histamine-induced skin testing, making the diagnosis very challenging. Oral formulations of antihistamines are well known to diminish skin test reactivity, but ocular application has never been studied to our knowledge. This study was performed to evaluate whether olopatadine hydrochloride 0.2% ophthalmic solution suppressed histamine-induced wheals and flares on skin-prick testing. A randomized, double-blinded, placebo-controlled, single-center, cross-over pilot study was performed that compared histamine-induced wheal and flare areas after 7-10 days of treatment with both olopatadine 0.2% ophthalmic solution and artificial tears, allowing for a 7- to 10-day washout period between medications. From a total of 24 patients randomized, 21 subjects completed the study, 86% of whom were female. There were no statistically significant differences among both the wheal and the flare areas when comparing treatment with olopatadine and placebo, under the 5% significance level. Although characterized by a small sample size and a preponderance of female subjects, our data suggest that olopatadine does not suppress wheal and flare areas during allergy testing, and discontinuation in preparation for skin-prick testing does not appear to be necessary.