Table 1. Characteristics of the included studies.
| Study (year) | Country | Mean age (year) | Indication | Modality | Cumulative dose | Follow-up (month) | N (all) | Not located | Outcomes assessd |
|---|---|---|---|---|---|---|---|---|---|
| Tari 1990ǂ | Italy | (5–12) | PAR | Drops | 363STU | 18 | 66 | 8 | SS |
| Hirsch 1997ǂ | Germany | 10.6 (6–16) | PAR | Drops | 570 μg | 12 | 30 | 12 | SS |
| Passalacqua 1998є | Italy | 26.1 (15–46) | PAR | Tablets | 47,225 AU | 24 | 20 | 1 | SS |
| Mungan 1999є | Turkey | 31.3 (18–46) | PAR and asthma | Drops | NA | 12 | 36 | 0 | SS MS |
| Guez 2000§ | France | 26.4 (6–51) | PAR | Drops | 90,000 IR | 24 | 72 | 33 | SS MS |
| Bahçeciler 2001ǂ | Turkey | 11.7 (7–18) | PAR | Drops | 7,000 IR | 6 | 15 | 0 | SS MS |
| Ippoliti 2002ǂ | Italy | 9 (5–12) | PAR and asthma | Drops | 12 mg | 6 | 86 | 0 | SS |
| Marcucci 2003ǂ | Italy | 8.5 (4–16) | PAR | Drops | 110 μg | 12 | 24 | 0 | SS |
| Passalacqua 2006є | Italy | 31.28 (18–49) | PAR | Tables | 208,000 AU | 24 | 68 | 12 | SS MS |
| Tseng 2008ǂ | Taiwan | 9.7 (6–18) | PAR | Drops | 37,312 IR | 6 | 63 | 4 | SS |
| O'Hehir 2009є | Australia | 33.2 (18–56) | PAR | Drops | NA | 24 | 30 | 3 | SS |
| Eifan 2010ǂⱷ | Turkey | 7 (5–10) | PAR | Drops | 73,876.8 STU | 12 | 48 | 5 | SS MS |
| Yonekura 2010ǂ | Japan | 9.5 (7–15) | PAR | Drops | 200 μg | 10 | 31 | 3 | SS MS |
| de Bot 2012ǂ | Netherlands | 11.7 (6–18) | PAR | Drops | 435 μg | 24 | 257 | 38 | SS |
| Yukselen 2012ǂ | Turkey | 10.1 | PAR and asthma | Drops | 173,733 TU | 12 | 32 | 2 | SS MS |
| Aydogan 2013ǂ | Turkey | (5–10) | PAR | Drops | 44,500 IR | 12 | 18 | 2 | SS MS |
| Bozek 2013є | Poland | 66.3 (60-75) | PAR | Drops | 421,200 IR | 36 | 108 | 13 | SS MS |
| Wang 2013§ | China | (4–60) | PAR | Drops | NA | 6 | 120 | 35 | SS |
| Bergmann 2014є | Germany | (18–50) | PAR | Tables | 109,200 IR | ||||
| 180,500 IR | 12 | 509 | 112 | SS MS | |||||
| Shao 2014ǂⱷ | China | 6.2 (3–13) | PAR | Drops | 2,638.7 μg | 12 | 264 | 46 | SS MS |
| Huang 2015єⱷ | China | 23.7 (16–52) | PAR | Drops | NA | 24 | 112 | 9 | SS MS |
| Mosbech 2015§ | Multi-center | 30.1 (14–75) | PAR and asthma | Tables | 2,190SQ-HDM | ||||
| 1,095SQ-HDM | |||||||||
| 365SQ-HDM | 12 | 489 | 56 | SS MS | |||||
| Nolte 2015є | Austria | 27.3 (18–58) | PAR | Tables | NA | 6 | 124 | 18 | SS |
| Potter 2015є | South Africe | 32.9 (18-60) | PAR | Drops | 93,600 IR | 24 | 60 | 12 | SS |
| Demoly 2016є | Germany | (18–65) | PAR | Tables | NA | 12 | 992 | 115 | SS MS |
‡Study only included pediatric patients; єStudy only included adults; §Study included both children and adults; ⱷOpen-label randomized controlled trial.
PAR, perennial allergic rhinitis; AU, allergic units; IR, index of reactivity; STU,specific treatment units; SQ-HDM, standardized quality HDM; TU, treatment units; mg, milligram; ug, micrograms; N, sample size; SS, symptom score; MS, medication score.