Dermatitis®

To determine the prevalence of allergic reactions to gold among patients tested by the North American Contact Dermatitis Group (NACDG) from 1996 to 1998.

This is a prospective analysis of patch test results from the 12 centers that comprise the NACDG. Gold was tested as gold sodium thiosulfate (0.5% in petrolatum [pet]), along with 49 other screening allergens, in patients presenting with possible contact dermatitis.

Of 4,101 patients tested, 388 (9.5%) had a positive patch test result to gold. Women accounted for 62.8% of the subjects tested and 90.2% of patients positive to gold (P < .0001). The most common sites of dermatitis in gold-allergic patients were the hands (29.6%), face (19.3%), and eyelids (7.5%). Nickel and cobalt allergies, respectively, also were present in 33.5% and 18.3% of gold allergic individuals, as compared with 14.2% and 9.0% of the total population. Gold was the only positive reaction in 15.2% of the 388 patients.

Gold is a more common allergen than previously reported and might cause facial and eyelid dermatitis. Hypersensitivity to gold is statistically linked to female gender and to allergic reactions to nickel and cobalt.

Although the Murine Local Lymph Node Assay (LLNA) is efficient in identifying chemi-cals with sensitizing potential, there is increasing need for alternative end points. Cinnamaldehyde (CIN) was chosen for evaluation based on its moderate potency and extensive use in fragrance materials.

The purpose of the present studies is to incorporate some alternative end points, such as phenotypic analysis and cytokine production, into a modified LLNA/irritancy assay (IA) to evaluate the sensitization of female B6C3F1 mice to CIN.

Several nontraditional end points, including the analysis of lymphocyte subpopulations, B7 costimulatory molecule and cytokine messenger RNA (mRNA) expression, and intracellular inter-feron-γ (IFN-γ) levels, were incorporated into a modified murine local lymph node (LLNA)/irritancy assay (IA) to evaluate the sensitization of female B6C3F1 mice to cinnamaldehyde (CIN).

The alternate end points used in these studies support the classification of CIN as a moderately potent sensitizer. Dermal treatment with CIN resulted in an increase in the percentage of B cells in the auricular lymph nodes (ALNs) and expression of the costimulatory molecule, B7-2, on B cells. Lymph node cells also showed increased transforming growth factor-β1, migration-inhibition factor, and mild increases in IFN-γ and interleukin-2 cytokine mRNA expression. Although the increase in IFN-γ mRNA expression did not translate into increased intracellular IFN-γ levels, the absolute number of T cells producing IFN-γ in the ALNs increased. Conversely, the MEST did not classify CIN as a contact allergen.

The nontraditional end points used in the LLNA/IA were not as sensitive as the traditional radioisotope method used to assess cell proliferation. However, they may help identify compounds inappropriately classified as sensitizers or nonsensitizers by the LLNA and MEST.

Compositae mix and sesquiterpene-lactone (SL) mix are important patch test substances to show allergic contact dermatitis from various Compositae plants.

The aims of this study are to calculate the sensitization rates to Compositae mix and SL mix in an occupational dermatology clinic and to describe cases of active sensitization caused by patch testing with Compositae mix and SL mix.

Conventional patch testing was performed. SL mix (0.1%) and Compositae mix (6% in petrolatum) were tested in a modified European standard series and a plant allergen series. Testing with other appropriate patch test series was also performed.

SL mix provoked 8 allergic patch test reactions (0.7%) in 1,076 patients, whereas Compositae mix was positive in 15 of 346 patients (4.2%). Three patients were actively sensitized to Compositae mix and 1 patient to SL mix. One patient was also sensitized to other plant allergens in a series of allergenic plant chemicals, namely to Mansonone A, an ortho-quinone; (R)-3,4-dimethoxydalbergione, a quinone; and Chlorophorin, a hydroxy stilbene. Allergic patch test reactions to laurel leaf were caused by cross-sensitization to SLs.

Compositae mix seems to be a more important patch test substance than SL mix to detect allergic contact dermatitis to Compositae plants, but patch testing may sensitize. The concentration of the individual components of the Compositae mix should be adjusted so that the mix detects allergic patients but does not sensitize.

Many different patch systems are available for predicting contact dermatitis. It is important to determine the ideal patch to meet the objective of the testing method.

The 21-day cumulative irritation test is well accepted for predicting irritation after repeated exposures. The patch type must allow separation of materials to predict irritation potential in the marketplace. Three patch systems were compared to determine which best provides this separation and prediction.

Four test materials were evaluated using 3 patch systems in a 21-day cumulative irritation test. Tested were water, 0.06% sodium lauryl sulfate (SLS), and 2 underarm products (UAP), one having lower and one having higher irritation potential. The patch types were; Webril pad and 8-mm and 12-mm Finn Chambers.

Both the 12-mm Finn Chamber and Webril pad showed the ability to differentiate the higher irritating UAP and the 0.06% SLS from the lower irritation UAP product and water. The 8-mm Finn chamber was less discriminating, showing the 0.06% SLS to be the same as water and the lower-irritating UAP.

The Webril pad and the 12-mm Finn Chamber are better at discriminating irritation potential than is the 8-mm Finn Chamber. The 12-mm Finn Chamber might also allow discrimination with a lower degree of irritation.

Test chambers for irritant patch testing are usually larger than those used in allergic patch testing. In general, larger areas show stronger skin reactions than smaller areas.

This study investigated whether this difference is of practical relevance, when a model irritant is applied in small and large Finn chambers and evaluated by measurement of transepidermal water loss (TEWL).

Patch testing was performed with 2 concentrations of sodium lauryl sulfate (SLS) (0.25% and 0.5%) on forearms of healthy volunteers. Large (inner diameter, 12 mm) and small (inner diameter, 8 mm) chambers were used.

A variance analysis (3 factors, 2-tailed) showed that the test outcome, as assessed by TEWL, was strongly dependent on SLS test concentration and test chamber size. The larger chambers gave approximately 30% to 50% higher values than the smaller.

This may be explained by the fact that with the small chambers, the adjacent small area of nontreated skin was also assessed by the evaporimeter, biasing the results. A formula estimating TEWL value of the large chamber from values of the small chambers has been proposed.