Barrier properties of inflamed denture-loaded palatal mucosa to water.

The barrier property of inflamed palatal mucosa to water has been studied in eight adult edentulous persons with a generalized denture stomatitis, by measuring the transmucosal water flow under varying osmotic gradients. Flow rates were registered gravimetrically in solute saturated filter paper discs after 10-min periods of mucosal contact, using solutions with an osmolarity of 0, 0.25, 0.30, 0.38, 0.50 and 0.75 osmol sucrose/l. The histology of the mucosal areas was evaluated from cytologic scrapings, and biopsy material from two persons. The inflow with use of pure water was 2.98 mg/cm2/10 min, being about three and a half times greater than through the intact mucosal surface. The point of isotony of the inflamed mucosa ranged between 0.30 and 0.36 with a mean value of 0.33 osmol/l, thus being of the same magnitude as in plasma and tissue fluid. The observations from the biopsy material were in accordance with earlier histological evidence from generalized denture stomatitis, indicating that the permeability properties of the inflamed mucosa belonged to epithelial cell layers located in the lower part of the spinous layer.     

The role of cadmium as a skin sensitizing agent in denture and non-denture wearers

Positive patch test reactions to cadmium were observed in 8 out of 21 denture wearing persons with burning mouth sensations during 1979 and 1980, and in 13 of 125 consecutive outpatients being routine tested at the Dermatological Department in late 1980 and early 1981. Retesting 17 of these patients after at least 3 months delay with 2.0% cadmium chloride and 2% cadmium sulphate in water showed only 7 with a definite positive reaction. At serial dilution of cadmium sulphate, only 1 person reacted to a 1% aqueous solution. An exposure to cadmium could in 1 case be traced back to a 2-year period of work in a PVC plant, while in the remaining 6 cases the most probable exposure factor seemed to be chronic heavy cigarette smoking. The observations did not lend support to the pink acrylic denture base material being a relevant cadmium exposure factor.     

Decreasing trends in methyldibromo glutaronitrile contact allergy--following regulatory intervention

Background:  The preservative methyldibromo glutaronitrile (MDBGN) has been banned, first from stay-on, and later from rinse-off cosmetics, in the EU countries because of increasing rates of contact allergy.
Objectives:  To evaluate the frequency of contact allergy to MDBGN among patients patch tested by the Danish Contact Dermatitis Group just before and following regulatory decisions.
Patients/Methods:  The data set comprised 19 279 consecutive eczema patients patch tested from 2003–2007 with MDBGN 0.3% in petrolatum (pet.) or, in a minority of patients, with Euxyl K™ 400 1.5% in pet.
Results:  A significantly decreasing trend in the frequency of positive patch tests to MDBGN was found from 4.6% in 2003 to 2.6% in 2007 ( P  < 0.001). The decreasing trend was seen for both men and women. A significantly decreasing proportion of cases with a current relevance of contact allergy to MDBGN was also seen from 51.3% in 2003 to 29% in 2007 ( P  < 0.001).
Conclusions:  Regulatory interventions have already had a major effect on allergic disease due to MDBGN in Denmark. The same trends are likely to be seen in other EU countries.     

Quantitative determinations of sensory and pain thresholds on human oral mucosa by argon laser stimulation.

High-energy light from an argon laser was applied to human oral mucosa in order to investigate regional pain sensitivity. Significant regional differences in sensory and pain thresholds were observed between the test sites on the hard and soft palatal mucosa, the buccal mucosa, the tongue, the lower lip, and the skin on the hand. Pain thresholds were lowest on the tip of the tongue and highest on the hard palate. Sensory and pain thresholds were influenced by different stimulus parameters: pulse duration and laser beam diameter. Blackening of the mucosa in regions with high optical reflectance, such as the hard palate, increased light absorption and, hence, reduced both thresholds significantly. Reflectance spectrophotometric measurements indicated that the hard palatal mucosa reflected argon laser light about 1.5 times more than the tip of the tongue. The different threshold values could, in part, be ascribed to different reflectance and absorption properties of the mucosal areas but also indicated substantial regional variation in pain sensitivity of the human oral mucosa. Measurement of laser thresholds is an appropriate and standardized method for investigating sensory differences in human oral mucosa and may be used to study various pain conditions, e.g., burning mouth syndrome.     

Exposure of nickel and the relevance of nickel sensitivity among hospital cleaners

The nickel content of water specimens from consecutive stages during the cleaning process in a Danish hospital was analyzed. Statistically significant increases of the nickel concentrations were found from step to step of the cleaning, eventually exceeding the theoretical sensitizing safety limit. The relevance of the findings in relation to hand eczema is discussed.     

The significance of chromate ingestion in patients allergic to chromate.

A double-blind study was carried out to demonstrate the significance of chromate ingestion in the persistence of chromic chromate dermatitis. Each of 31 chromate-allergic patients was given one tablet containing 7.1 mg potassium dichromate, plus a placebo tablet. The dermatitis of 11 of the 31 patients flared after the ingestion of chromate, but not after placebo. 3 patients had equivocal reactions to both tablets; the dermatitis worsened in 2 patients following ingestion of the placebo but not after the chromate tablet. No statistically significant difference could be found between reactivity to chromate and eczema of dyshidrotic morphology. Nor was it possible to correlate the degree of patch test reactivity to the reaction following chromate ingestion. It is concluded that a low-chromate diet is of value in the management of patients with chronic chromate dermatitis.