Patients with negative patch tests (NPTs) have distinct characteristics, according to a recent study, which includes being male, aged ≤40 years, and non-Caucasian. Researchers conducted a retrospective cross-sectional analysis of 34,822 patch tested patients. NPTs were defined as negative or irritant final interpretations of all North American Contact Dermatitis Group (NACDG) screening allergens and no relevant allergens on supplemental series. They found:
- Almost one-third (n=10,888, 31.3%) of patients had negative results.
- NPT patients were significantly more likely to have dermatitis primarily involving the following body sites: scattered generalized, lips, or eyelids.
- However, absolute differences in age, race, and site were small and may not be clinically meaningful.
- NPT patients were significantly less likely to have occupationally related skin disease.
- Overall, 8.3% of NPT patients had occupationally related skin disease with precision production workers/machine operators (28.5%), healthcare workers (17.0%), and mechanics/repairers (7.5%) being the most commonly related occupations.
- 22.9% of NPT patients had relevant irritants and 41.6% of irritants were occupationally related; cosmetics/health care products and soaps were common sources for both occupationally related and non-occupationally related irritants.
Warshaw EM, Zhang AJ, Belsito DV, et al. Patients with negative patch tests: Retrospective analysis of North American Contact Dermatitis Group (NACDG) Data 2001-2016. [Published online ahead of print January 10, 2019]. J Am Acad Dermatol. doi:10.1016/j.jaad.2018.12.062.
This Week's Must Reads
Dietary Changes: No Major Effect on Psoriasis, Dermatol Online J; 2019 Feb 15; Pona, et al
Influenza Vaccine Rates in Adults with Psoriasis, J Invest Dermatol; 2019 Feb; Noe, Shin, et al
Psoriasis and AD Share Inflammatory Components, J Invest Dermatol; ePub 2019 Jan 11; Tsoi, et al
Quality of Life Among Patients with Psoriasis, PsA, Arch Dermatol Res; ePub 2019 Mar 13; Duvetorp, et al
Psoriasis and Cardiometabolic Comorbidity in Women, Acta Derm Venereol; 2019 Mar 1; Blegvad, et al
Must Reads in Contact Dermatitis
Negative Patch Test Patients Share Distinct Traits, J Am Acad Dermatol; ePub 2019 Jan 10; Warshaw, et al
Nickel Allergy: Significant Rise in North America, J Am Acad Dermatol; ePub 2018 Oct 17; Warshaw, et al
Farm Living Inversely Linked with Skin Allergy, Ann Allergy Asthma Immunol; ePub 2018 Apr 6, Patel, et al
More Than 50 Allergens Linked with Skin Cleansers, Dermatitis; ePub 2017 Dec 18; Warshaw, et al
Patch-Test Reactions to Essential Oils Evaluated, Dermatitis; ePub 2017 Jun 13; Warshaw, et al