stearates and Dermatitis--Irritant

Irritant contact dermatitis of the hands is very common in dental laboratory technicians due to frequent contact with various irritants. Barrier creams (HS) are often avoided because a tight grip of tools and small objects is necessary; furthermore dental objects must not be contaminated by HS. In this study the efficacy of HS applied during working hours was compared to skin care products (HP) applied only after work.. 2 popular commercial HS (HS-1, HS-2) and 2 moisturizers containing urea and beeswax respectively (HP-1, HP-2) were evaluated in 5 laboratories by a total of 192 technicians. Every technician used one HS (several applications during working hours) and one HP applied at home at least once daily for 4 weeks each with a wash-out period of 2 weeks in between. The sequence HS-HP, HP-HS was randomized for every laboratory in two single blind cross over designs for both combinations (HS-1 with HP-1, HS-2 with HP-2). The technicians scored the products on a scale of efficacy (worse, none, good, very good). The skin condition was evaluated by a dermatologist at the beginning of the study, after 4, 6 and 10 weeks on a scale for erythema, infiltration, vesicles, fissures and scaling to produce a sum score. Furthermore, transepidermal water loss (TEWL) was measured on the back of the hand and on the ventral aspect of the forearm at the beginnung and the end of the 4 weeks application period. The quotient of these two parameters was used for statistical evaluation (covariance analysis).. The assessment of either "good" or "very good" was as follows: HS-1 58%; HS-2 67%; HP-1 77%; HP-2 98%. Both HP, particularly HP-2, were judged superior to either HS. This was confirmed by the improvement of the skin condition (HS-1 35%; HS-2 44%; HP-1 55%; HP-2 56%). Statistical significance of the differences in TEWL data was clearly demonstrated: HP-1 better than HS-1 (p = 0.007); HP-2 better than HS-2 (p = 0.03). The acceptance of the products was high. The majority was willing to continue its usage after the study (68 %-89 %).. The results demonstrate that the use of after work moisturizers is highly beneficial and under the chosen study conditions even superior to barrier creams applied at work. This approach is more practical for many professions and may effectively reduce the frequency of irritant contact dermatitis.

Topics: Adolescent; Adult; Benzenesulfonates; Dental Technicians; Dermatitis, Irritant; Dermatitis, Occupational; Drug Administration Schedule; Drug Combinations; Female; Humans; Laboratories, Dental; Lanolin; Male; Middle Aged; Protective Agents; Self Care; Skin Cream; Stearates; Young Adult

Topics: Adult; Benzenesulfonates; Body Water; Castor Oil; Dermatitis, Irritant; Drug Combinations; Epidermis; Erythema; Female; Humans; Hydrogen-Ion Concentration; Laser-Doppler Flowmetry; Lipids; Male; Ointments; Permeability; Regional Blood Flow; Sebum; Siloxanes; Skin; Sodium Dodecyl Sulfate; Stearates; Waxes

An improved human model for the quantification of skin barrier creams (BCs) is described. In contrast to the previously published procedure, the back, instead of the forearm, and a total of 4 irritants are used. Due to the larger area, 3 BC formulations can be simultaneously compared to the control field, which receives the irritant only, without BC-pretreatment. On 10 human volunteers, the irritants 10% sodium lauryl sulfate (SLS), 1% sodium hydroxide (NaOH), 30% lactic acid (LA) and undiluted toluene (TOL) were applied via large Finn Chambers for 30 min, 5 x during the 1st week and 4 x during the 2nd week. Taktosan Salbe (water-in-oil emulsion) and RAWI Speerschutzcreme (oil-in-water emulsion) were applied 30 min before contact with the irritants. In order to assess reproducibility and interindividual variation, the BC RAWI was tested in duplicate. Irritant cutaneous reactions were quantified by 4 parameters: erythema score, transepidermal water loss, blood flow volume and stratum corneum hydration by measuring capacitance. The results showed marked differences in efficacy. Taktosan significantly suppressed irritation by SLS, NaOH and LA, which was apparent in nearly all parameters. RAWI caused significant inhibition of SLS irritation, and a positive trend against NaOH and LA was observed. Both BCs failed against TOL. The results of duplicate testing with RAWI showed good reproducibility. The dogma that oil-in-water emulsions are primarily effective against lipophilic irritants, and water-in-oil emulsions against hydrophilic irritants, needs to be re-evaluated on the basis of our findings. This model seems to have potential for further studies on BCs and might elucidate the complex interaction of BCs with irritants.

Topics: Adult; Benzenesulfonates; Dermatitis, Contact; Dermatitis, Irritant; Dermatologic Agents; Emulsions; Female; Humans; Irritants; Male; Middle Aged; Ointments; Reproducibility of Results; Skin Tests; Stearates

The effect of a protective cream was tested in a new tandem repeated irritation test with tandem application of 0.5% sodium lauryl sulphate (SLS) and undiluted toluene. The irritants were applied twice daily for 30 min to the ventral forearms of 20 volunteers. Irritant cutaneous reactions were quantified by a visual score, transepidermal water loss, chromametry and skin capacitance. Concurrent application of SLS/toluene induced stronger reactions than those caused by twice daily application of each irritant on its own. A protective effect of the protective cream was obtained against all treatment combinations and was significant for SLS/SLS (p < or = 0.01) and SLS/ toluene (p < or = 0.05). Our results indicate that the tandem repetitive irritation test has great potential in the evaluation of skin care products to prevent irritant contact dermatitis.

Topics: Adolescent; Adult; Benzenesulfonates; Colorimetry; Dermatitis, Irritant; Drug Combinations; Female; Forearm; Galvanic Skin Response; Humans; Irritants; Lanolin; Male; Middle Aged; Skin; Skin Tests; Sodium Dodecyl Sulfate; Stearates; Toluene; Water Loss, Insensible

An animal model for the evaluation of skin protective creams against chemical irritants is described. The irritants were applied daily for 2 weeks to shaved back skin of young guinea pigs: sodium lauryl sulphate (5% aq.; 30 min), sodium hydroxide (0.5% aq.; 2 min), and toluene (20% eth.; 2 min). The barrier cream was applied 2 h prior to and immediately after exposure to the irritant. Control animals were treated with the irritant only. The irritant reaction was scored on a 4-point scale for erythema and quantified with regard to transepidermal water loss (TEWL) by evaporimetry and skin blood flow volume (BFV) by laser Doppler velocimetry. A total of 90 guinea pigs, consisting of individual panels of 5 to 10 animals, was tested. While one barrier cream (Stokoderm) significantly suppressed the irritation due to sodium lauryl sulphate and toluene, the other (Contra-Alkali) failed to do so and even aggravated the response, which was particularly evident with sodium hydroxide. This model may be useful in developing more effective barrier creams.

Topics: Animals; Benzenesulfonates; Blood Flow Velocity; Buffers; Dermatitis, Irritant; Drug Combinations; Emulsions; Guinea Pigs; Lanolin; Laser-Doppler Flowmetry; Models, Biological; Oils; Skin; Skin Tests; Sodium Dodecyl Sulfate; Sodium Hydroxide; Stearates; Time Factors; Toluene; Water Loss, Insensible