Table 1.
Characteristics of included studies.
| Study | Characteristics |
|---|---|
| Bardin, 2018 | |
| General information | Publication format: journal publication (abstract) |
| Publication year (language): 2018 (English) | |
| Country: Vietnam | |
| Design | Type: case–control study |
| Setting: hospital | |
| Inclusion criteria: used allopurinol | |
| Exclusion criteria: not reported | |
| Patient demographics | Number of patients investigated: 10 in SCAR group, 112 in tolerant group |
| Age (years): mean 55 (SD 12) in SCAR group, mean 46 (SD 12) in tolerant group | |
| Sex (female): 2/10 (20%) in SCAR group, 0/112 (0%) in tolerant group | |
| Race: Asian | |
| Ethnic origin: South and Southeast Asia | |
| Exposure | Dosing of allopurinol (mg/day): mean 345 (SD 142) in SCAR group, mean 356 (SD 114) in tolerant group |
| Duration of allopurinol (days): not reported | |
| Outcomes | SJS, SJS/TEN, TEN |
| Cao, 2012 | |
| General information | Publication format: journal publication (full-text) |
| Publication year (language): 2012 (English) | |
| Country: China | |
| Design | Type: case–control study |
| Setting: hospital and population | |
| Inclusion criteria: for hospital setting: used allopurinol | |
| Exclusion criteria: not reported | |
| Patient demographics | Number of patients investigated: 38 in SCAR group, 63 in tolerant group, 572 in population group |
| Age (years): mean 63.8 (SD 14.4) in SCAR group, mean 60.9 (SD 15.1) in tolerant group, not reported in population group | |
| Sex (female): 12/38 (31.6%) in SCAR group, 6/63 (9.5%) in tolerant group, not reported in population group | |
| Race: Asian | |
| Ethnic origin: East and Central Asia | |
| Exposure | Dosing of allopurinol (mg/day): median 300 (IQR 100–600) in SCAR group, not clearly reported in tolerant group |
| Duration of allopurinol (days): mean 26.2 (SD 13.5) in SCAR group, mean 122.7 (SD 11.6) in tolerant group | |
| Outcomes | DRESS, MPE, SJS/TEN |
| Cheng, 2015 | |
| General information | Publication format: journal publication (full-text) |
| Publication year (language): 2015 (English) | |
| Country: China | |
| Design | Type: case–control study |
| Setting: hospital and population | |
| Inclusion criteria: for hospital setting: (1) were Han Chinese; (2) used allopurinol | |
| Exclusion criteria: had history of bone marrow transplantation, chemotherapy or cancer | |
| Patient demographics | Number of patients investigated: 92 in SCAR group, 75 in tolerant group, 99 in population group |
| Age (years): mean 59.1 (SD 1.6) in SCAR group, mean 53.4 (SD 1.5) in tolerant group, mean 49.3 (SD 0.6) in population group | |
| Sex (female): 32/92 (34.8%) in SCAR group, 4/75 (5.3%) in tolerant group, 35/99 (35.4%) in population group | |
| Race: Asian | |
| Ethnic origin: East and Central Asia | |
| Exposure | Dosing of allopurinol (mg/day): mean 186.5 (SD 13.7) in SCAR group, mean 289.8 (SD 15.2) in tolerant group |
| Duration of allopurinol (days): mean 22.0 (SD 1.5) in SCAR group, mean 1153.4 (SD 303.0) in tolerant group | |
| Outcomes | DRESS, SJS, SJS/TEN, TEN |
| Chiu, 2012 | |
| General information | Publication format: journal publication (full-text) |
| Publication date (language): 2012 (English) | |
| Country: China | |
| Design | Type: case–control study |
| Setting: hospital | |
| Inclusion criteria: used allopurinol | |
| Exclusion criteria: were not Han Chinese | |
| Patient demographics | Number of patients investigated: 20 in SCAR group, 30 in tolerant group |
| Age (years): median 68.5 (IQR 33–96) in SCAR group, median 71.5 (IQR 41–97) in tolerant group | |
| Sex (female): 9/20 (45.0%) in SCAR group, 4/30 (13.3%) in tolerant group | |
| Race: Asian | |
| Ethnic origin: East and Central Asia | |
| Exposure | Dosing of allopurinol (mg/day): median 250 (IQR 100–600) in SCAR group, median 200 (IQR 100–300) in tolerant group |
| Duration of allopurinol (days): median 24.5 (IQR 10–56) in SCAR group, median 1620 (365–5400) in tolerant group | |
| Outcomes | DRESS, EMM, SJS, TEN |
| Cristallo, 2011 | |
| General information | Publication format: journal publication (full-text) |
| Publication date (language): 2011 (English) | |
| Country: Italy | |
| Design | Type: case–control study |
| Setting: hospital and population | |
| Inclusion criteria: White (Northern Italy) | |
| Exclusion criteria: not clearly reported | |
| Patient demographics | Number of patients investigated: 7 in SCAR group, 115 in population group |
| Age: mean 64.0 (SD 9.7) in SCAR group, not reported in population group | |
| Sex (female): 4/7 (57.1%) in SCAR group, not reported in population group | |
| Race: White | |
| Ethnic origin: Eastern/Western Europe | |
| Exposure | Dosing of allopurinol (mg/day): not reported |
| Duration of allopurinol (days): not reported | |
| Outcomes | SJS, TEN |
| Do, 2015 | |
| General information | Publication format: journal publication (full-text) |
| Publication date (language): 2015 (Vietnamese) | |
| Country: Vietnam | |
| Design | Type: case–control study |
| Setting: hospital and population | |
| Inclusion criteria: for hospital setting: used allopurinol | |
| Exclusion criteria: not reported | |
| Patient demographics | Number of patients investigated: 22 in SCAR group, 75 in population group |
| Age (> 60 years): 10/22 (45.5%) in SCAR group, not reported in population group | |
| Sex (female): 11/22 (50.0%) in SCAR group, not reported in population group | |
| Race: Asian | |
| Ethnic origin: South and Southeast Asia | |
| Exposure | Dosing of allopurinol (mg/day): median 300 (IQR 300–300) in SCAR group |
| Duration of allopurinol (days): not reported | |
| Outcomes | DRESS, MPE, SJS/TEN |
| Do, 2019 | |
| General information | Publication format: journal publication (full-text) |
| Publication date (language): 2019 (Vietnamese) | |
| Country: Vietnam | |
| Design | Type: case–control study |
| Setting: hospital | |
| Inclusion criteria: (1) had gout; (2) used allopurinol | |
| Exclusion criteria: (1) using medications with high risk of allergy; (2) prior intermittent use of allopurinol | |
| Patient demographics | Number of patients investigated: 7 in SCAR group, 128 in tolerant group |
| Age: mean 49.0 in SCAR group, mean 46.3 in tolerant group | |
| Sex (female): 2/7 (28.6%) in SCAR group, 0/128 (0.0%) in tolerant group | |
| Race: Asian | |
| Ethnicity: South and Southeast Asia | |
| Exposure | Dosing of allopurinol (mg/day): median 300 in SCAR group, median 300 in tolerant group |
| Duration of allopurinol (days): median 18 in SCAR group, median 260.5 in tolerant group | |
| Outcomes | SJS, SJS/TEN |
| Do, 2020 | |
| General information | Publication format: journal publication (full-text) |
| Publication date (language): 2020 (English) | |
| Country: Vietnam | |
| Design | Type: case–control study |
| Setting: hospital | |
| Inclusion criteria: used allopurinol | |
| Exclusion criteria: not reported | |
| Patient demographics | Number of patients investigated: 31 in SCAR group, 395 in tolerant group |
| Age (years): mean 60.0 (SD 15.9) in SCAR group, mean 45.4 (SD 10.3) in tolerant group | |
| Sex (female): 9/31 (29.0%) in SCAR group, 0/395 (0.0%) in tolerant group | |
| Race: Asian | |
| Ethnicity: South and Southeast Asia | |
| Exposure | Dosing of allopurinol (mg/day): mean 303.4 (SD 97.2) in SCAR group, mean 369.1 (SD 103.8) in tolerant group |
| Duration of allopurinol (days): not reported | |
| Outcomes | DRESS, SJS/TEN |
| Gonçalo, 2013 | |
| General information | Publication format: journal publication (full-text) |
| Publication date (language): 2013 (English) | |
| Country: Portugal | |
| Design | Type: case–control study |
| Setting: hospital and population | |
| Inclusion criteria: for hospital setting: used allopurinol | |
| Exclusion criteria: not reported | |
| Patient demographics | Number of patients investigated: 25 in SCAR group, 23 in tolerant group, 3200 in population group |
| Age (years): mean 67.4 (SD 16.0) in SCAR group, mean 62.0 in tolerant group, mean 32.0 in population group | |
| Sex (female): 14/25 (56.0%) in SCAR group, 7/23 (30.4%) in tolerant group, 65% in population group | |
| Race: White | |
| Ethnicity: Eastern/Western Europe | |
| Exposure | Dosing of allopurinol (mg/day): median 300 in SCAR and tolerant group |
| Duration of allopurinol (days): > 4 months in tolerant group | |
| Outcomes | DRESS, SJS, SJS/TEN, TEN |
| Hung, 2005 | |
| General information | Publication format: journal publication (full-text) |
| Publication date (language): 2005 (English) | |
| Country: Taiwan | |
| Design | Type: case–control study |
| Setting: hospital and population | |
| Inclusion criteria: for hospital setting: used allopurinol | |
| Exclusion criteria: not reported | |
| Patient demographics | Number of patients investigated: 51 in SCAR group, 135 in tolerant group, 93 in population group |
| Age (years): median 66 (IQR 18–91) in SCAR group, median 56 (IQR 21–84) in tolerant group, not reported in population group | |
| Sex (female): 27/51 (52.9%) in SCAR group, 10/135 (7.4%) in tolerant group, not reported in population group | |
| Race: Asian | |
| Ethnicity: East and Central Asia | |
| Exposure | Dosing of allopurinol (mg/day): median 100 (IQR 50–300) in SCAR group, median 150 (IQR 100–400) in tolerant group |
| Duration of allopurinol (days): median 26 (IQR 1–56) in SCAR group, median 22 (IQR 6–107) in tolerant group | |
| Outcomes | DRESS, SJS, SJS/TEN, TEN |
| Jung, 2011 | |
| General information | Publication format: journal publication (full-text) |
| Publication date (language): 2011 (English) | |
| Country: South Korea | |
| Design | Type: case–control study |
| Setting: hospital | |
| Inclusion criteria: (1) had chronic kidney disease stage 3–5 or post-kidney transplantation; (2) used allopurinol | |
| Exclusion criteria: used allopurinol for < 60 days in tolerant group | |
| Patient demographics | Number of patients investigated: 9 in SCAR group, 432 in tolerant group |
| Age (years): mean 41.6 (SD 15.9) in SCAR group, mean 35.9 (SD 18.1) in tolerant group | |
| Sex (female): 3/9 (33.3%) in SCAR group, 114/432 (26.4%) in tolerant group | |
| Race: Asian | |
| Ethnicity: East and Central Asia | |
| Exposure | Dosing of allopurinol (mg/day): mean 112.5 (SD 38.7) in SCAR group, mean 100 (SD 50.1) in tolerant group |
| Duration of allopurinol (days): mean 59.1 (SD 45.5) in SCAR group, mean 887.1 (SD 821.3) in tolerant group | |
| Outcomes | DRESS, SJS |
| Kang, 2011 | |
| General information | Publication format: journal publication (full-text) |
| Publication date (language): 2011 (English) | |
| Country: South Korea | |
| Design | Type: case–control study |
| Setting: hospital and population | |
| Inclusion criteria: not clearly reported (for tolerant group: chronic kidney disease) | |
| Exclusion criteria: not reported | |
| Patient demographics | Number of patients investigated: 25 in SCAR group, 57 in tolerant group, 485 in population group |
| Age (years): median 58 (IQR 35–80) in SCAR group, median 51 (IQR 20–76) in tolerant group, not reported in population group | |
| Sex (female): 11/25 (44.0%) in SCAR group, 20/57 (35.1%) in tolerant group, not reported in population group | |
| Race: Asian | |
| Ethnicity: East and Central Asia | |
| Exposure | Dosing of allopurinol (mg/day): median 150 (IQR 100–600) in SCAR group, median 100 (IQR 50–200) in tolerant group |
| Duration of allopurinol (months): median 1.0 (IQR 0.2–5.3) in SCAR group, median 29.1 (IQR 6–72) in tolerant group | |
| Outcomes | DRESS, SJS/TEN |
| Kaniwa, 2008 | |
| General information | Publication format: journal publication (full-text) |
| Publication date (language): 2008 (English) | |
| Country: Japan | |
| Design | Type: case–control study |
| Setting: hospital and population | |
| Inclusion criteria: not reported | |
| Exclusion criteria: not reported | |
| Patient demographics | Number of patients investigated: 10 in SCAR group, 493 in population group |
| Age (years): median 74 (IQR 67–76.5) in SCAR group, not reported in other groups | |
| Sex (female): 2/10 (20.0%) in SCAR group, not reported in other groups | |
| Race: Asian | |
| Ethnicity: East and Central Asia | |
| Exposure | Dosing of allopurinol (mg/day): not reported |
| Duration of allopurinol (days): not reported | |
| Outcomes | SJS, TEN |
| Lonjou, 2008 | |
| General information | Publication format: journal publication (full-text) |
| Publication date (language): 2008 (English) | |
| Country: European countries | |
| Design | Type: case–control study |
| Setting: hospital and population | |
| Inclusion criteria: for hospital setting: used allopurinol | |
| Exclusion criteria: not reported | |
| Patient demographics | Number of patients investigated: 31 in SCAR group, 1822 in population group |
| Age (years): median 56 (IQR 40–71.5) in SCAR group, not reported in other groups | |
| Sex (female): 13/31 (41.9%) in SCAR group, not reported in other groups | |
| Race: White (87.1%), Asian (6.5%), African (3.2%), South American (3.2%) | |
| Ethnicity: Eastern/Western Europe | |
| Exposure | Dosing of allopurinol (mg/day): not reported |
| Duration of allopurinol (days): not reported | |
| Outcomes | SJS, SJS/TEN, TEN |
| Low, 2020 | |
| General information | Publication format: journal publication (full-text) |
| Publication date (language): 2020 (English) | |
| Country: Malaysia | |
| Design | Type: case–control study |
| Setting: hospital | |
| Inclusion criteria: (1) aged ≥ 18; (2) used allopurinol | |
| Exclusion criteria: not reported | |
| Patient demographics | Number of patients investigated: 55 in SCAR group, 42 in tolerant group |
| Age (years): mean 64.9 in SCAR group, mean 59.9 in tolerant group | |
| Sex (female): not reported | |
| Race: Asian | |
| Ethnicity: South and Southeast Asia (59.8%), East and Central Asia (40.2%) | |
| Exposure | Dosing of allopurinol (mg/day): not reported |
| Duration of allopurinol (days): not reported | |
| Outcomes | AGEP, DRESS, SJS/TEN |
| Ng, 2016 | |
| General information | Publication format: journal publication (full-text) |
| Publication date (language): 2016 (English) | |
| Country: Taiwan | |
| Design | Type: case–control study |
| Setting: hopsital | |
| Inclusion criteria: used allopurinol | |
| Exclusion criteria: not reported | |
| Patient demographics | Number of patients investigated: 146 in SCAR group, 285 in tolerant group |
| Age (years): mean 65 (SD 16) in SCAR group, mean 59 (SD 14) in tolerant group | |
| Sex (female): 66/146 (45.2%) in SCAR group, 17/285 (6.0%) in tolerant group | |
| Race: Asian | |
| Ethnicity: East and Central Asia | |
| Exposure | Dosing of allopurinol (mg/day): not reported |
| Duration of allopurinol (days): not reported | |
| Outcomes | DRESS, DRESS/SJS/TEN, MPE, SJS, SJS/TEN |
| Nguyen, 2021 | |
| General information | Publication format: journal publication (full-text) |
| Publication date (language): 2021 (English) | |
| Country: Vietnam | |
| Design | Type: case–control study |
| Setting: hospital | |
| Inclusion criteria: used allopurinol | |
| Exclusion criteria: not reported | |
| Patient demographics | Number of patients investigated: 81 in SCAR group, 74 in tolerant group |
| Age (years): mean 57.6 (SD 14.6) in SCAR group, mean 60.3 (SD 11.4) in tolerant group | |
| Sex (female): 20/81 (24.7%) in SCAR group, 9/74 (12.2%) in tolerant group | |
| Race: Asian | |
| Ethnicity: South and Southeast Asia | |
| Exposure | Dosing of allopurinol (mg/day): mean 324.7 (SD 121.0) in SCAR group, mean 281.8 (SD ) in tolerant group |
| Duration of allopurinol (days): not reported | |
| Outcomes | AGEP/SJS, DRESS, DRESS/SJS/TEN, SJS/TEN |
| Niihara, 2013 | |
| General information | Publication format: journal publication (full-text) |
| Publication date (language): 2013 (English) | |
| Country: Japan | |
| Design | Type: case–control study |
| Setting: hospital | |
| Inclusion criteria: used allopurinol | |
| Exclusion criteria: not reported | |
| Patient demographics | Number of patients investigated: 7 in SCAR group, 25 in tolerant group |
| Age (years): median 72 (IQR 68.5–78.5) in SCAR group, not reported in tolerant group | |
| Sex (female): 2/7 (28.6%) in SCAR group, not reported in tolerant group | |
| Race: Asian | |
| Ethnicity: East and Central Asia | |
| Exposure | Dosing of allopurinol (mg/day): not reported |
| Duration of allopurinol (days): not reported | |
| Outcomes | SJS, EMM |
| Park, 2016 | |
| General information | Publication format: journal publication (full-text) |
| Publication date (language): 2016 (English) | |
| Country: South Korea | |
| Design | Type: case–control study |
| Setting: hospital | |
| Inclusion criteria: used allopurinol | |
| Exclusion criteria: not reported | |
| Patient demographics | Number of patients investigated: 9 in SCAR group, 949 in tolerant group |
| Age (years): not reported | |
| Sex (female): not reported | |
| Race: Asian | |
| Ethnicity: East and Central Asia | |
| Exposure | Dosing of allopurinol (mg/day): not reported |
| Duration of allopurinol (days): not reported | |
| Outcomes | SJS/TEN |
| Pham, 2022 | |
| General information | Publication format: journal publication (full-text) |
| Publication date (language): 2022 (English) | |
| Country: Vietnam | |
| Design | Type: case–control study |
| Setting: hospital and population | |
| Inclusion criteria: for hospital setting: used allopurinol | |
| Exclusion criteria: (1) bullous autoimmune skin diseases; (2) erythema multiforme/erythema infectiosum; (3) Kawasaki disease; (4) bone marrow transplantation; (5) acropustulosis; (6) Von Zumbusch psoriasis; and (7) concomitant use of another drug of high allergy potential at SCARs onset | |
| Patient demographics | Number of patients investigated: 100 in SCAR group, 183 in tolerant group, 810 in population group |
| Age (years): mean 58.5 (SD 14.2) in SCAR group, mean 55.2 (SD 12.2) in tolerant group, not reported in population group | |
| Sex (female): 24/100 (24.0%) in SCAR group, 29/183 (15.8%) in tolerant group, not reported in population group | |
| Race: Asian | |
| Ethnicity: South and Southeast Asia | |
| Exposure | Dosing of allopurinol (> 150 mg/day): 96/100 (96.0%) in SCAR group, 164/183 (89.6%) in tolerant group |
| Duration of allopurinol (days): not reported | |
| Outcomes | DRESS, DRESS/SJS/TEN, SJS, SJS/TEN, TEN |
| Saksit, 2017 | |
| General information | Publication format: journal publication (full-text) |
| Publication date (language): 2017 (English) | |
| Country: Thailand | |
| Design | Type: case–control study |
| Setting: hospital | |
| Inclusion criteria: used allopurinol | |
| Exclusion criteria: not reported | |
| Patient demographics | Number of patients investigated: 86 in SCAR group, 182 in tolerant group |
| Age (years): median 68 (IQR 28–84) in SCAR group, median 66 (IQR 29–91) in tolerant group | |
| Sex (female): 45/86 (52.3%) in SCAR group, 39 (21.4%) in tolerant group | |
| Race: Asian | |
| Ethnicity: South and Southeast Asia | |
| Exposure | Dosing of allopurinol (mg/day): median 100 (IQR 50–300) in SCAR group, median 100 (IQR 50–400) in tolerant group |
| Duration of allopurinol (days): median 19 (IQR 2–60) in SCAR group, median not reported in tolerant group (mean > 180) | |
| Outcomes | DRESS, SJS/TEN |
| Sukasem, 2016 | |
| General information | Publication format: journal publication (full-text) |
| Publication date (language): 2016 (English) | |
| Country: Thailand | |
| Design | Type: case–control study |
| Setting: hospital and population | |
| Inclusion criteria: for hospital setting: used allopurinol | |
| Exclusion criteria: not reported | |
| Patient demographics | Number of patients investigated: 30 in SCAR group, 100 in tolerant group, 1095 in population group |
| Age (years): median 73 (IQR 30–88) in SCAR group, not reported in other groups | |
| Sex (female): 13/30 (43.3%) in SCAR group, not reported in other groups | |
| Race: Asian | |
| Ethnicity: South and Southeast Asia | |
| Exposure | Dosing of allopurinol (mg/day): mean 239.9 (SD 87.0) in SCAR group, not reported in other groups |
| Duration of allopurinol (days): mean 16.4 (SD 14.3), not reported in other groups | |
| Outcomes | DRESS, MPE, SJS/TEN |
| Tassaneeyakul, 2009 | |
| General information | Publication format: journal publication (full-text) |
| Publication year (language): 2009 (English) | |
| Country: Thailand | |
| Design | Type: case–control study |
| Setting: hospital | |
| Inclusion criteria: (1) used allopurinol; (2) agreed to participate | |
| Exclusion criteria: not reported | |
| Patient demographics | Number of patients investigated: 27 in SCAR group, 54 in tolerant group |
| Age (years): median 65 (IQR 38–81) in SCAR group, median 63.5 (IQR 46–90) in tolerant group | |
| Sex (female): 12/27 (44.4%) in SCAR group, 11/54 (20.4%) in tolerant group | |
| Race: Asian | |
| Ethnicity: South and Southeast Asian | |
| Exposure | Dosing of allopurinol (mg/day): not reported |
| Duration of allopurinol (days): median 14 (IQR 3–50) in SCAR group, median 780 (IQR 90–18,000) in tolerant group | |
| Outcomes | SJS, SJS/TEN, TEN |
| Tohkin, 2013 | |
| General information | Publication format: journal publication (full-text) |
| Publication year (language): 2013 (English) | |
| Country: Japan | |
| Design | Type: case–control study |
| Setting: hospital and population | |
| Inclusion criteria: for hospital setting: used allopurinol | |
| Exclusion criteria: not reported | |
| Patient demographics | Number of patients investigated: 18 in SCAR group, 986 in population group |
| Age (years): mean 72.3 (SD 10.0) in SCAR group, not reported in population group | |
| Sex (female): 6/18 (33.3%) in SCAR group, not reported in population group | |
| Race: Asian | |
| Ethnicity: East and Central Asia | |
| Exposure | Dosing of allopurinol (mg/day): not reported |
| Duration of allopurinol (days): mean 21.7 (SD 11.9), not reported in population group | |
| Outcomes | SJS, TEN |
AGEP: acute generalised exanthematous pustulosis; DRESS: drug reaction with eosinophilia and systemic symptoms; EMM: erythema multiforme major; IQR: interquartile range; MPE: maculopapular eruption; SCAR: severe cutaneous adverse reaction; SD: standard deviation; SJS: Stevens–Johnson syndrome; SJS/TEN: Stevens–Johnson/toxic epidermal necrolysis overlap syndrome; and TEN: toxic epidermal necrolysis (TEN).
In the context of SCARs, DRESS can also be referred as drug hypersensitivity syndrome (DHS), drug-induced hypersensitivity syndrome (DIHS), or hypersensitivity syndrome (HSS). To ensure consistency, outcomes that were reported as DHS, DIHS, or HSS were classified as DRESS.