Table 1. Clinical Prevalence of Contact Allergens and Products Containing Them.
| Allergena | Clinical prevalence, rankb | NPCPs with ingredient, No. (%) (N = 1651) |
|---|---|---|
| Fragrance mixc | 1 | 605 (36.6) |
| Eugenolc,d | 1 | 40 (2.4) |
| Hexyl cinnamalc,d | 3 | 57 (3.5) |
| Cinnamic alcoholc,d | 3 | 1 (0.1) |
| MCI, MITd | 9 | 23 (1.4) |
| Propylene glycol | 10 | 162 (9.8) |
| Iodopropynyl butylcarbamate | 11 | 37 (2.2) |
| P-phenylenediamine | 13 | 2 (0.1) |
| Propolis | 14 | 7 (0.4) |
| Cocamidopropyl betaine | 20 | 129 (7.8) |
| Linalool | 21 | 297 (18.0) |
| Benzoyl peroxide | 28 | 2 (0.1) |
| Dimethylaminopropylamine | 30 | 1 (0.1) |
| Decyl glucoside | 31 | 98 (5.9) |
| Limonenec | 32 | 309 (18.7) |
| Rosin | 35 | 2 (0.1) |
| Diazolidinyl urea | 41 | 17 (1.0) |
| Benzoate | 44 | 428 (25.9) |
| Sodium benzoate | 44 | 381 (23.1) |
| Benzyl benzoate | 44 | 44 (2.7) |
| Benzoic acid | 44 | 117 (7.1) |
| Benzophenone-4 | 46 | 8 (0.5) |
| Tea tree (melaleuca) oil | 52 | 77 (4.7) |
| Benzalkonium chloride | 54 | 3 (0.2) |
| Benzyl salicylate | 58 | 63 (3.8) |
| Lanoline | 59 | 43 (2.6) |
| DMDM hydantoin | 60 | 14 (0.8) |
| Cocamide DEA | 61 | 1 (0.1) |
| Carmine | 62 | 19 (1.2) |
| Tocopherolf | 63 | 792 (48.0) |
| Ammonium persulfate | 64 | 1 (0.1) |
| Benzyl alcoholc | 65 | 189 (11.4) |
| Phenoxyethanol | 70 | 776 (47.0) |
| Benzophenone-3 | 71 | 5 (0.3) |
| Lauryl glucoside | 82 | 57 (3.5) |
| Chlorhexidine digluconate | 83 | 7 (0.4) |
| Propyl gallate | 89 | 1 (0.1) |
| Triethanolamine | 90 | 18 (1.1) |
| Amyl cinnamalc | 96 | 31 (1.9) |
| Jasminec | 97 | 32 (1.9) |
| Isoeugenolc | 98 | 2 (0.1) |
| Sorbic acid | 99 | 37 (2.2) |
| Peppermintc | 100 | 45 (2.7) |
| Cetyl alcohold,g | NA | 268 (16.2) |
| Stearyl alcohold,g | NA | 100 (6.1) |
| Lyralc,g,h | NA | 10 (0.6) |
| BHTg | NA | 2 (0.1) |
Abbreviations: BHT, butylated hydroxytoluene; DEA, diethanolamine; DMDM, 1,3-dimethylol-5, 5-dimethyl; MCI, methylchloroisothiazolinone; MIT, methylisothiazolinone; NA, not applicable; NPCPs, natural personal care products.
Seventy-three unique allergens were identified; the table includes 43 that were among the 100 most clinically prevalent sources of allergic contact dermatitis6 and 4 (cetyl alcohol, stearyl alcohol, Lyral, and BHA) that are clinically prevalent but were not among the top 100.
Based on data from Scheman et al.6
Commonly used as fragrance.
Clinical prevalence ranks shown are for closely related substances that would elicit a positive reaction: cetyl alcohol and stearyl alcohol (not ranked among the 100 most clinically prevalent allergens) test positive to cetylstearyl alcohol; eugenol is found in fragrance mix; hexyl cinnamal and cinnamic alcohol are common components of Balsam of Peru; and MCI cross-reacts with MIT.
Lanolin, lanolin alcohol, and wool alcohol.
Tocopherol and vitamin E.
Clinically prevalent but not among the 100 most clinically prevalent allergens.
Lyral and hydroxyisohexyl 3-cyclohexene carboxaldehyde.