xRead - September 2022

Wise et al.

Page 103

to prevent the onset of symptoms by interrupting the physiological response to nasal allergens.

Author Manuscript Author Manuscript Author Manuscript Author Manuscript

DSCG was discovered over 50 years ago, and since that time other cromoglycate type agents (chromones) have been developed. The chromones have demonstrated the ability to inhibit the early-phase and late-phase reactions of asthma. 1351 Initial studies focused on histamine and cytokine release from mast cells. More recent studies have shown anti-allergy activity unrelated to mast cell activation, but rather through the inhibition of macrophages, eosinophils, monocytes, and platelets. 1352-1354 DSCG can be used in an inhaled form as a prophylactic agent in the treatment of mild to moderate asthma, as a nasal spray to treat SAR, or as an ophthalmic solution to treat allergic or vernal conjunctivitis. DSCG may also be taken orally to control allergic reactions to certain foods. It can be used for patients 2 years and older but has a short half-life requiring dosing of 3 to 6 times daily. 1355 DSCG has an excellent safety profile, although the need for frequent dosing may affect compliance. Minor adverse effects include nasal irritation or burning, sneezing, epistaxis, and bad taste. 1355 Most studies comparing DSCG directly to placebo have shown that it is effective in patients with SAR (Table IX.B.5). Studies on the efficacy of DSCG in PAR have been controversial. 1356-1360 In a recent RCT, Lejeune et al. 1356 examined the role of DSCG in monosensitized PAR patients and found that DSCG resulted in significant reduction in symptom scores for nasal obstruction, discharge, and sneezing compared to placebo. When compared to INCS, DSCG has been shown to be less effective. 1357,1361-1369 To date, there have been no direct comparisons between DSCG and intranasal antihistamines. Ultimately, the role of DSCG as a primary treatment for AR is limited given its lower efficacy when compared to INCS and potential compliance challenges secondary to frequent dosing regimen. • Aggregate Grade of Evidence: A (Level 1b: 13 studies; Level 2b: 9 studies; Table IX.B.5). • Benefit: DSCG is effective in reducing sneezing, rhinorrhea, and nasal congestion. • Harm: Rare local side effects include nasopharyngeal irritation, sneezing, rhinorrhea, and headache. • Cost: Low. • Benefits-Harm Assessment: Preponderance of benefit over harm. Benefit is considered mild to moderate. Less effective than INCS. • Value Judgments: Useful for preventative short-term use in patients with known exposure risks. • Policy Level: Option. • Intervention: DSCG may be considered for the treatment of AR, particularly in patients known triggers who cannot tolerate INCS.

Int Forum Allergy Rhinol . Author manuscript; available in PMC 2020 June 10.