Patch Test Results of the Dermatology Clinic Zurich in 1989: Personal Computer-Aided Statistical Evaluation

Abstract

The patch test results of 921 consecutively tested patients were registered on an IBM personal computer. A computer program based on the dBase III plus database software, especially designed for this purpose, was used. The statistical evaluation was performed with dBase III plus. 59% of the probands were females and 41% males. The average age was 42.8 years. 26% of the probands were inpatients and 74% outpatients. A majority of the patients presented with eczema of the hands, face or the lower legs. The largest occupational groups were houseworkers and cleaning personnel, office workers and pensioners. To 450 of the 921 patients, at least 4 test series were applied simultaneously. These included European standard, vehicles and emulgators, topical medications, and preservatives and biocides. The other 20 test series available were employed only by 2-81 patients each. The highest sensitization rates were found with: nickel, 18.7%; cobalt, 10.2%; balsam of Peru, 8.8%; framycetin, 8.0%; neomycin, 6.8%; potassium dichromate, 6.1%; p-phenylene diamine, 5.4%; paramix, 4.9%; formaldehyde, 4.8%, and (chlor)methylisothiazolinone, 4.7%. The critical evaluation of the data showed two kinds of problems: first, test-specific aspects led to optimization of the patch test procedures; second, the crucial importance of an adequate statistical analysis for epidemiological investigation was revealed.

Airborne contact dermatitis from methylchloroisothiazolinone in wall paint. Abolition of symptoms by chemical allergen inactivation

“…In the European Community the maximal concentration of MCI/MI in cosmetic products has been limited to 15 ppm and labelling is mandatory. Despite that effort MCI/MI is still among the most common contact allergens, the rate of sensitization in Europe ranging from about 0.7 to 8.4% (3)(4)(5)(6)(7)(8)(9)(10). MCI is a more potent sensitizer than MI (11).…”

<p>Emollient formulations containing antiseptics reduce effectively the level of <em>Staphylococcus aureus</em> on skin</p>

“…Both have low toxicity and are rarely sensitizing 21,22. Benzalkonium chloride has been shown to cause irritation at high concentrations, but is unlikely to cause irritation at the low concentrations used in this study 23. The main advantages of antiseptics over antibiotics are that they have a low potential of inducing bacterial resistance and rarely cause hypersensitivity 11,12.…”