Allergic contact dermatitis is recognized as a public health problem and some major allergens have been subject to intervention aiming at lowering skin exposure. There is an obvious interest in evaluating the effect of such interventions. Population studies are difficult to perform and epidemiological studies based on clinical data from testing patients with contact dermatitis are common surrogates. Our objective was to gather Swedish clinical standard series test data on two occasions in order to monitor trends in sensitization rates. Consecutive patch test results from the Swedish standard series were collected from 9 centres from 1991 to 1993 and from 1999 to 2001. In total, 3680 and 3790 patients, respectively, were included. Crude, age-adjusted and age-stratified prevalence are given separately for women and men. Our top 10 allergens are much in line with newly published European test data. Significant changes among those allergens are increasing sensitization rates for Myroxylon pereirae and decreasing rates for colophony, 5-chloro-2-methyl-4-iso-thi-azo-lin-3-one, Amerchol L 101 and thiuram mix. Nickel allergy is decreasing among young women. Among less common allergens, a noteworthy increase of sensitization to 4-phenyl-en-diamine is found. In conclusion, significant trends in sensitization rates of important allergen, reflecting changes in exposure, have been found.

Piercing the earlobes has increased in popularity among males in recent years. This habit would be expected to increase the incidence of nickel and cobalt sensitization. Patch testing with nickel sulfate and cobalt chloride was performed in 520 young Swedish men doing compulsory military service. The overall frequency of nickel/cobalt positive tests was 4.2%. The prevalence of nickel/cobalt positive tests was significantly higher (p < 0.05) in 152 men with pierced earlobes (7.9%) than in those 368 with unpierced earlobes (2.7%). A history of hand eczema (7/152 = 4.6%) or other types of eczema (22/152 = 14.5%) in individuals with pierced earlobes was no more common than in those with unpierced earlobes: 24/368 = 6.5% and 51/386 = 13.9%, respectively (n.s.). Hand eczema was no more common in sensitized (1/22 = 4.5%) than in nonsensitized individuals (32/498 = 6.4%) (n.s.).

This report reviews how to set up a laser Doppler perfusion imaging system intended for visualization of skin blood perfusion, capture images and evaluate the results obtained. A brief summary of related papers published in the literature within the areas of skin irritant and allergy patch testing, microdialysis and skin tumour circulation is presented, as well as early applications within other fields such as diabetology, wound healing and microvascular research.

853 hard metal workers were patch tested with nickel sulphate 5%, potassium dichromate 0.5% and cobalt chloride 1%, each in petrolatum. Non-allergic reactions appeared in 6.5% of the nickel tests, 13% of the chromium tests and 18.3% of the cobalt tests. Most of the individuals with positive, poral or pustular reactions were retested with serial dilutions of metal salts in pet. and in water. The accuracy of a positive initial nickel reaction was 83%, a chromium reaction 40% and a cobalt reaction 62%. The nonallergic reactions were partly reproducible and correlated with both the type of patch test material and with individual factors. Weak and moderately strong positive patch test reactions to metal salts may be irritant and should be checked with serial dilution tests or at least be retested. A reduction of the cobalt chloride concentration from 1% to 0.5% in the standard test material is discussed.

The need for a large database, the usefulness of multicentre data collection, as well as the benefit of a representative collection of cases from clinical practice, were demonstrated in this trial. Images that were difficult to classify using the NN expert system were not identical to those found difficult to classify by clinicians. We suggest therefore that the combination of clinician and computer may potentially increase the accuracy of PSL diagnosis. This may result in improved detection of melanoma and a reduction in unnecessary excisions.