Jp Nater

Prevalence, incidence and course of eczema on the hands and forearms in a sample of the general population

In 1979, the inhabitants of a geographically defined area were examined for skin disorders of the hands and forearms. In 1982 this cohort was invited for re‐examination. In persons with eczema, patch testing was performed. Irritant factors were found to play a rôle in 73% of the cases, whereas a contact allergy could be detected in 30%. The must frequent allergens were nickel sulphate (20%), potassium dichromate (6%), land cobalt chloride (4%). In some persons with a definite history of allergy to metals, no positive patch test with nickel, chromate or cobalt could be obtained; other mechanisms may be involved. Significantly more positive patch tests were found among persons with an eczema of longer than 2 years duration compared with persons, with eczema present for a shorter period of time, indicating that many cases of eczema are primarily of irritant nature, but later complicated by sensitisation.

PREVALENCE OF ECZEMA AND OTHER DERMATOSES OF THE HANDS AND ARMS IN THE NETHERLANDS - ASSOCIATION WITH AGE AND OCCUPATION

In a sample of about 3000 adults the hands and arms were examined for the presence of skin disorders. The most important diagnostic category was eczema; prevalence among males was 4.6% and among females it was 8%. In the majority of patients with eczema irritant factors were found to play a role. Among males occupation was a major factor associated with prevalence of eczema. After correction for occupation there remained no association with age.

Vulnerability of the skin to surfactants in different groups of eczema patients and controls as measured by water vapour loss

Healthy unaffected skin of the volar side of the forearm of patients with eczema and of controls was exposed during a period of 48 h to a 100 μl of a 2 g/v% solution of eight surfactants and distilled water by the large Finn chamber method.

Susceptibility to primary irritants: age dependence and relation to contact allergic reactions.

Patch tests with three primary irritants were performed in 600 persons with eczema and in 33 healthy controls. The irritants assayed were: croton oil (20 %) in mineral oil, thymoquinone (1 %) in ethanol and crotonaldehyde (7.5 %) plus sodium lauryl sulphate (4 %) in aqua dest. The number of positive reactions to croton oil was found to decrease with age, while for thymoquinone and crotonaldehyde and for the total irritant score no age dependence was observed. No significant correlation was found between sensitization to common contact allergens and susceptibility 10 irritants. The incidence of positive reactions to common allergens proved to increase with age.

Eczematous (irritant and allergic) reactions of the skin and barrier function as determined by water vapour loss

The aim of this study was to compare the influence of irritant and allergic reactions on the barrier function of the skin and to correlate disturbances of barrier function with macroscopically visible changes.

DINITROCHLOROBENZENE SENSITISATION TEST IN WOMEN ON HORMONAL CONTRACEPTIVES

Cell-mediated immunity was measured in women on hormonal contraceptives using the 2,4-dinitrochlorobenzene (D.N.C.B.) sensitisation test. Three groups of women were studied: forty-eight women were taking oral contraceptives of combined oestrogen/progestogen (thirty-seven of them had used oral contraceptives for a year or longer); twelve women were using a sequential pill (ethinyloestradiol and megestrolacetate); and sixteen women had received intramuscular injections of medroxyprogesterone acetate. The results were compared with those of a control group of twenty-nine age-matched women not taking contraceptive steroids. In women on the combined contraceptive pill and those who had received intramuscular progesterone, mean D.N.C.B. reactivity was significantly increased. The results were even more striking in women who had used combined contraceptive pills for more than one year. These results do not accord with the previously reported decrease in cell-mediated immunity in women on hormonal contraceptives.

Measurement of transepidermal water loss

Dear Sir We would like to make a number of comments regarding the articles by Berardesca & Maibach (I, 2). The values given for the baseline TEWL for the skin of the back were 2. 7 ± 0. 7 g/h (I) and 2.7±0.7 mgfcm2h (2) for the white skinned. The former statement is most likely an error, since in that same publication (I), in other tables, the units are given as mgfcm2h: or more accurately mgfcm2h. Considering then the baseline values of 2. 7 ± 0. 7 mg/cm2h (2), when converted into g/m2h, the values become 27.0±7.0 g/m2h. This is the unit displayed on the Evaporimeter (ServoMed, Stockholm) for TEWL. The baseline values for this same skin site reported by Lamrnintausta et a!. (3) are 3.7±0.6 g/m/h. We gather it to have been g/m2h, since in their previous report (4), the values given (3.22±0.65 for males and 3.35±0.69 for females) were in gjm2/h, or more accurately, gjm2h. The values given by Berardesca & Maibach (I, 2), when converted, are then more than 7 times greater than those values reported by Lamrnintausta et a!. (3, 4). Although the latter values are normalised to corresponding values at a skin temperature of 30°C, in our experience (5, 6), this cannot account for the 7-fold increase in the reported values (1, 2). The values by Lamrnintausta et a!. (3, 4) seem possible for the skin of the back, when considering the values for that same site reported by Baker & Kligman (0.29 ± 0.04 mg/ = h) (7), but the latter investigators used electrical hygrometry (7), whereas both Berardesca & Lammintausta (I-4) used the water vapour gradient estimation by the Evaporimeter. Therefore, direct comparisons are not feasible. Regional variation in TEWL has been reported by Baker & Kligman (7). The differences between the back, forearm, and abdomen are probably not significant, when considering the diffusion constants and the mean stratum corneum thicknesses for these skin sites (7). The increased diffusivity of other regions, such as the forehead, dorsum of the hand, and the palm is, however, without question (7). The constancy of this diffusive water loss from any one area from day-to-day was reported as high (7). In view of this, the large 7-fold discrepancy between the reported water loss values (1-4) for the same skin site is questionable. We have recently reported (6) on the comparison of water loss values measured with different Evaporimeters. Although considerable inter-instrumental variation was observed, the maximum differences were only 2fold (6). It is therefore tempting to attribute the discrepancies in the reported water loss values (I, 2) both to the instrumentation and to possible differences in the methodology of these measurements. Subclinical eccrine sweating may also have contributed to these results (7). Clarification of these values (1, 2) for the skin of the back is thus required, so as to be able to identify the regional differences in baseline TEWL of the human skin, by Evaporimetric measurements. The discrepancies mentioned above emphasize the need (6) for standardisation of the methodology and instrumentation for TEWL measurements.

CONTACT URTICARIAL SKIN-RESPONSES TO CINNAMALDEHYDE

A patient suffering from an eczema of the right hand showed after routine patch testing an immediate urticarial reaction to cinnamaldehyde.

PREVALENCE OF ECZEMA AND OTHER DERMATOSES OF THE HANDS AND FOREARMS IN CONSTRUCTION WORKERS IN THE NETHERLANDS

An examination of the hands and forearms of about 1700 construction workers revealed that 133 of them (7.8%) had a form of eczema, whereas psoriasis was observed in twenty‐two (1.3%). Irritant dermatitis was the major diagnostic category and was found in sixty‐seven workers (4%); allergic contact eczema was found in 1.4%. The prevalence of eczema/dermatitis in different job categories varied between 5.9% in technicians and 12.6% in bricklayers and plasterers.

Contact allergy to dithranol

During treatment with a dithranol-containing collodion for common warts, a patient developed a eczematous reaction on the treated sites and the extremities. Patch testing revealed a contact allergy to dithranol. Two applications of the collodion cured the warts within 3 weeks. It is argued that contact allergy to dithranol occurs more frequently than is suspected.