Table 2.
Frequency of Positive Patch Test Results in Patients with LPP and/or FFA Compared with Rates in the European General Population
| Allergen | Prasaad et al., 2020 (N = 42) | Aldoori et al., 2016 (N= 40) | Rocha et al., 2018 (N = 63) | Pastor-Nieto et al., 2021 (N = 36) | Diepgen et al., 2016 (N = 3,119) |
|---|---|---|---|---|---|
| Percentage of patients with at least one positive relevant allergen | 76% | 52.5% | 27% | 80.5% | 27% |
| Gallates | 26.2% | 16.6% | |||
| Fragrance Mix I | 14.3% | 10.0% | 5.0% | 8.3% | 0.9% |
| Linalool | 19.0% | 22.5% | 8.0% | 5.5% | |
| Limonene | 4.8% | 13.8% | |||
| Ammonium persulfate | 14.3% | ||||
| Benzophenone 4 | 14.3% | 12.5% | 8.0% | ||
| Benzyl salicylate | 4.8% | 22% | |||
| Propolis | 9.5% | 16.6% | |||
| MI/MCI | 11.9% | 17.5% | 2.8% | 0.5% | |
| Balsam of Peru | 7.1% | 12.5% | 8.0% | 5.5% | 0.7% |
Abbreviations: FFA, frontal fibrosing alopecia; LPP, lichen planopilaris; MI/MCI, methylisothiazolinone/methylchloroisothiazolinone.