Dermatitis®

Accurate patch testing is reliant on proper preparation of patch test allergens. The stability of patch test allergens is dependent on several factors including vapor pressure (VP).

This investigation reviews the VP of American Contact Dermatitis Society Core Allergens and compares stability predictions based on VP with those established through clinical testing.

Standard references were accessed for determining VP in millimeters of mercury and associated temperature in degrees celsius. If multiple values were listed, VP at temperatures that most approximate indoor storage conditions (20°C and 25°C) were chosen. For mixes, the individual component with the highest VP was chosen as the overall VP, assuming that the most volatile substance would evaporate first. Antigens were grouped into low (≤0.001 mm Hg), moderate (<1 to >0.001 mm Hg), and high (≥1 mm Hg) volatility using arbitrary cutoff values.

This review is consistent with previously reported data on formaldehyde, acrylates, and fragrance material instability. Given lack of testing data, VP can be useful in predicting patch test compound stability. Measures such as air-tight multidose reagent containers, sealed single-application dispensers, preparation of patches immediately before application, and storage at lower temperatures may remedy some of these issues.

Cobalt was recently identified in a leather couch responsible for dermatitis. Cobalt content/release in leather in the United States is unknown. We evaluated leather for cobalt content/release and investigated screening methods for identifying cobalt in leather.

One hundred thirty-one leather swatches were screened for cobalt content/release with X-ray fluorescence (XRF) spectrometry and cobalt indicator solution (CIS). Samples with positive screens and 1 negative control were analyzed using inductively-coupled plasma mass spectrometry (ICPMS).

CIS showed that 5 of 131 samples contained cobalt, subsequently found to be between 1 and 190 parts per million (ppm) when evaluated with ICPMS. The XRF analysis showed that 6 samples contained >5% cobalt, subsequently found to contain greater than 300 ppm cobalt by ICPMS. 7 of 12 tested swatches contained cobalt in excess of 100 ppm. One sample contained greater than 1000 ppm cobalt. The prevalence of swatches containing cobalt at levels in excess of 190 ppm was at least 5% (n = 7; total, N = 131).

Some leather consumer goods contain and release cobalt. Cobalt indicator solution is a poor screening test for cobalt in leather while XRF screening may be effective. Leather is a new source of cobalt exposure. Exposures to metal allergens are changing in ways that impact clinical decision making.

Hexavalent chromium in cement is a common cause of occupational allergic contact dermatitis (OACD).

Analysis of patch test data during 1999 to 2013 was done. Patients with cement-induced chromate OACD filled the Dermatology Life Quality Index, graded 1 to 5.

Of 4846 consecutive patients who were patch tested, 146 (3%) were chromate-sensitive. Of 46 (31.5%) who presented with chromate OACD, 27 (59%) had cement-induced chromate OACD. The proportion of chromate-sensitive patients with clinically relevant cement exposure increased from 7.7% in 2002 to 2004 to 28.7% in 2011 to 2013 (P = 0.04). The median age of presentation was younger than for other chromate-sensitive patients (32 vs 42 years). Hand eczema (88.9%) was the most frequent clinical presentation. Of the 27 with cement-induced chromate OACD, 21 (77.8%) had ongoing dermatitis at the time of the review. Although 14/27 (51.9%) changed their occupation to avoid exposure to cement, symptoms persisted in 9/14 (64.3%). Prolonged exposure to cement before development of symptoms was associated with chronicity. All the symptomatic patients experienced at least a moderate effect on their quality of life (grade 3 or higher on the Dermatology Life Quality Index).

We recommend the adoption of the European legislation in Israel, to reduce the prevalence of chromate OACD from cement.

Oral lichenoid lesions (OLLs) cannot be distinguished from oral lichen planus (OLP) except that causative factors can be identified. Amalgam is one of the causative allergens, and replacement may lead to resolution.

The aim of this study was to determine the prevalence, prognosis, and aggravating factors of amalgam contact allergy in patients with OLLs.

A clinical retrospective and prospective cohort study was carried out at the Dermatology Department, Siriraj Hospital, Mahidol University. In cases with patch test positive for an amalgam component, patients were suggested to replace their amalgam restorations.

Of 53 patients with OLLs, 39 (73.6%) had positive patch test results, and 31 (58.5%) reacted to at least one amalgam component. The most common causative allergen was mercury (35.8%). Lesions on bilateral buccal mucosa and gingiva tended to have negative patch test results (P < 0.05). Spicy food was the main aggravating factor. Amalgam replacements were performed in 10 patients. Clinical improvement was observed in all cases with complete healing in 3 cases.

The prevalence of amalgam contact allergy in patients with OLLs was 58.5%. Mercury was the most common allergen, followed by copper sulfate. An association between clinical, topographic relation, and positive patch test results would be a useful predictor for favorable outcome after amalgam removal.

Natural and synthetic rubbers containing rubber accelerators are well-known causes of occupational skin disease. Allergic contact dermatitis caused by rubber gloves is frequent and has almost exclusively been attributed to contact sensitization to accelerators.

This study aimed to evaluate the frequency of rubber accelerators sensitization in the population living in northeastern Italy, to find time trend and a correlation with occupations, and to investigate co-sensitization between rubber accelerators.

A population of 23,774 subjects was patch tested in 6 cities in northeastern Italy in the years 1996 to 2012 using carba mix 3%, thiuram mix 1%, benzothiazole (MBT) mix 1%, and isopropyl phenyl paraphenylamine diamine (IPPD) mix 0.6%.

The overall frequency of carbamates, MBT, thiurams, and IPPD mix sensitization was 3.4%, 0.65%, 1.75%, and 0.83%, respectively. On a logistic regression analysis (control group: white-collar workers), we found a statistically significant association to carbamates (odds ratio [OR], 1.3; 95% confidence interval [CI], 1.03–1.7) and thiurams (OR, 1.6; 95% CI, 1.1–2.3) for health care workers. Thiuram sensitivity was also significantly associated with dermatitis in maids and restaurant workers (OR, 2.2; 95% CI, 1.4–3.6), hairdressers (OR, 3.6; 95% CI, 1.8–7.1), shop assistants (OR, 2.9; 95% CI, 1.2–6.8), construction workers (OR, 2.7; 95% CI, 1.7–4.1), mechanics (OR, 2.1; 95% CI, 1.3–3.4), and professional drivers (OR, 2.6; 95% CI, 1.2–5.9).

In conclusion, our results demonstrated that rubber accelerators have an important role in allergic contact dermatitis in the northeast of Italy and their sensitization is associated significantly with occupations that wear gloves or use chemical substances. Between rubber accelerators tested, carbamates sensitization is prevalent and increasing during considered years.