House dust mite allergen immunotherapy in polysensitized people suffering from allergic rhinitis was as effective in improving visual analog scale (VAS), total nasal symptom score (TNSS), Rhinoconjunctivitis Quality of Life Questionnaire (RQLQ), total medication score (TMS), and combined symptom medication score (CSMS) as in monosensitized people.

Researchers sought to systematically review the safety and efficacy of house dust mite allergen immunotherapy compared between  polysensitized and monosensitized people suffering from allergic rhinitis. Databases such as  EMBASE, Cochrane central register of Controlled Trials (CENTRAL), PubMed/MEDLINE, and Scopus were searched. Alteration from baseline in TNSS was the key endpoint. Alteration from the baseline in VAS, TMS, CSMS, RQLQ score, immunological parameters, and adverse events were the secondary endpoints ascertained.

Out of 13 eligible research (2 retrospective cohorts, 1 matched cohort, and 10 prospective cohorts), 

10 papers were selected for quantitative synthesis. A total of 1,113 patients had allergic rhinitis, 566 of whom had developed a monosensitization to house dust mite, and 547 of whom had developed a polysensitization to house dust mite and additional allergens. With intermediate certainty of evidence, there was no discernible difference between the two groups' pooled mean alteration in VAS ( standardized mean difference [SMD] -0.20) and TNSS (SMD -0.05).

Alteration in RQLQ, CSMS, and TMS was comparable between the two arms (low certainty of evidence). The adverse events were mild and comparable between the two groups. The immunological indices were not predictive of clinical responses and remained inconsistent.

Since house dust mite allergens may be more prevalent in some subgroups of polysensitized individuals, treating clinically relevant house dust mite-allergic patients with house dust mite allergen immunotherapy may be a better option than limiting treatment to monosensitized individuals.