Effects of pretreatment with a urea-containing emollient on nickel allergic skin reactions.

The aim of this study was to evaluate the effect of a moisturizer containing urea on allergic contact dermatitis. Twenty-five nickel-sensitized patients and five controls (non-sensitized volunteers) applied such a moisturizer on the volar side of one forearm twice daily for 20 days, while the other forearm served as the control. After treatment with the moisturizer, patch tests with 0%, 0.5% and 2% NiSO4 in petrolatum were applied in a randomized manner on each arm. After 72 h, the skin reactions were blindly evaluated by clinical scoring and by measuring transepidermal water loss and electrical impedance. After treatment, the baseline transepidermal water loss values were lower and the baseline magnitude impedance index values were higher on the pretreated forearm. According to clinical scoring and measurements with the two physical measurement techniques, the degree of the patch test reactions was equal. All control subjects had negative nickel tests. We concluded that the skin reactivity to nickel in nickel-sensitized patients is not significantly affected by use of the urea-containing moisturizer.

Influence of childhood atopic dermatitis on future worklife.

OBJECTIVES: The purpose of this study was to perform a population-based follow-up of people with childhood atopic dermatitis with respect to the possible influence on their worklife. METHODS: Medical records of the school health care services in Stockholm, Sweden, were reviewed for people born between 1960 and 1969. Altogether 600 persons with signs of atopic dermatitis ("cases") and 600 matched controls without eczema ("controls") were identified. Of these people, 405 cases and 378 controls answered a postal questionnaire focusing on choice of job, occupational exposure, past and present skin disease, and change of job due to eczema. RESULTS: The proportions of cases and controls in jobs with a high risk of hand eczema were similar, as was the exposure to water, detergents, chemicals, and hand washing. The self-reported cumulative prevalence of hand eczema was 42% for the cases and 13% for the controls (P<0.001). The 1-year prevalence was 24% for the cases and 9% for the controls (P<0.001). Among the cases, 9% reported a change of job due to eczema compared with 2% of the controls (P<0.001). The corresponding proportions of sick leave were 10% and 2% (P<0.001). CONCLUSIONS: In conclusion, a history of atopic dermatitis in childhood does not seem to influence the choice of job nor hazardous occupational skin exposure. It does, however, mean an increased risk for job changes, sick leave, and medical consultations, mainly due to the increased risk of hand eczema.

Multicentre patch test study of air-oxidized ethoxylated surfactants.

Frequent exposure to water and surfactants is considered to be the main cause of hand eczema from wet work. Ethoxylated surfactants are susceptible to oxidation and some of the oxidation products formed have proved to be contact sensitizers in guinea pigs. The question of human sensitization to oxidized surfactants was addressed in a multicentre study in the Stockholm region. 528 consecutive dermatitis patients were patch tested with widely used ethoxylated surfactants in oxidized and non-oxidized form as well as certain identified oxidation compounds. 61 patients presented with mild, clearly irritant reactions to some of the surfactants tested. 18 patients showed not only erythema but also oedema and/or papules and vesicles, using a morphologic descriptive system for reading the patch test reactions. These reactions occurred mostly to oxidized surfactants and oxidation products. When retesting 9 of these 18 patients only an allergic reaction to acetaldehyde was confirmed. We conclude that oxidized ethoxylated surfactants have increased irritant potential compared to non-oxidized material. Our working hypothesis is that oxidized surfactants of technical quality exert a lower risk of sensitization than do oxidized homologous pure surfactants. Among the potential allergens formed during autoxidation, formaldehyde and acetaldehyde must be considered as a source of unexpected exposure.

Basal electrical impedance in relation to sodium lauryl sulphate-induced skin reactions--a comparison of patients with eczema and healthy controls.

BACKGROUND: Identification of subjects at risk for contact dermatitis by screening tests is desirable in order to adjust the preventive measures to individual skin susceptibility. The present study aimed to examine the effects of basic physiological features, such as baseline electrical impedance (IMP) and transepidermal water loss (TEWL), on reactivity to sodium lauryl sulphate (SLS). METHODS: On the basis of two previous studies, we re-evaluated the experimental irritant skin reactions (50 microL of 2% SLS in large Finn Chambers for 24 h) on the volar forearms of 29 patients with eczema and 19 healthy controls. RESULTS: We found definite differences in the baseline values of IMP, between the patients and the controls. Moreover, patients with eczema showed higher TEWL and lower MIX values on day 3 after exposure to SLS, which may indicate differences in SLS reactivity. After the study, the biophysical parameters of the eczema patients did not return to baseline, which suggests that their skin heals more slowly than that of normal subjects. CONCLUSIONS: Our findings indicate that the IMP technique may help to 'detect' chemically vulnerable skin. However, more studies are needed to determine the value of the basal electrical impedance parameters in assessing the risk of developing irritant contact dermatitis.

Electrical impedance as a potential tool to distinguish between allergic and irritant contact dermatitis.

BACKGROUND AND OBJECTIVE: The allergic contact reaction is a model reaction for studying the cell-mediated immune system of the skin. In this study we use a noninvasive method, electrical impedance (IMP), to compare nickel (Ni) allergic contact reactions with an irritant contact reaction induced by sodium lauryl sulfate, which has already been carefully evaluated with this method. For this purpose, we included only Ni- and sodium lauryl sulfate-induced reactions of very similar appearance. METHODS: Various concentrations of Ni sulfate in distilled water were applied on the volar aspect of the forearms of 33 adult women who were allergic to Ni. Assessments were made using visual scoring, a new IMP technique, and transepidermal water loss 3 and 7 days later. RESULTS: In the 19 patients who completed the study, 3 of the 4 impedance indices were significantly lower at the sodium lauryl sulfate sites than at the Ni sites on day 3; ie, the mean magnitude (MIX) (P < or = .001), imaginary part (IMAX) (P < or = .001), and real part (RIX) indices (P < or = .01). Unlike the irritant reactions, no significant increases in transepidermal water loss occurred in the allergic contact reactions. This may be because, in reactions of the studied magnitude, an allergic contact reaction does not significantly affect the epidermis because the inflammatory process is located deeper in the dermis than an irritant reaction. CONCLUSION: This study suggests that IMP, as used herein, is suitable for distinguishing between contact reactions of allergic and irritant nature. Although pathophysiologic events in the tissue studied significantly modify impedance patterns, little is known about how to interpret the structural and chemical changes underlying these patterns. Studies are needed to determine the relation between anatomic or pathophysiologic parameters, and the findings using IMP and other established methods, such as chemical extraction and histopathology.