Topical antioxidants protect the skin from chemical-induced irritation in the repetitive washing test: a placebo-controlled, double-blind study.

BACKGROUND: There is increasing evidence that reactive oxygen species play an important role in the development of both irritant and allergic contact dermatitis. OBJECTIVES: To assess the potential of topical antioxidants to prevent the development of experimentally induced irritant contact dermatitis. METHODS: We evaluated the effect of a cream containing a combination of antioxidants on sodium lauryl sulfate-induced irritant contact dermatitis in the repetitive washing test. As readout parameters for skin barrier function and cutaneous inflammation stratum corneum hydration, cutaneous blood flow and transepidermal water loss were assessed in 25 volunteers with bioengineering methods. RESULTS: In comparison with the cream base and a frequently used barrier cream, the antioxidant cream had high radical scavenging activity and effectively protected the skin from chemical-induced irritation. CONCLUSIONS: The superiority of the cream with antioxidants to the cream base suggests that reactive oxygen species, at least in part, play a role in the development of irritant contact dermatitis.

Treatment of irritant and allergic contact dermatitis.

The treatment of contact dermatitis lies principally in the avoidance of the offending agent. In certain circumstances, avoidance protocols are insurmountable, and therapy is rendered to assuage the inflammatory component and its consequent objective and subjective findings. However, the options thereafter vary, as some patients will require continuous symptomatic therapy despite avoidance of the purported offending agent. This manuscript will review established treatment options for contact dermatitis, such as corticosteroids and dietary manipulation, as well as discuss some promising new therapies from the last decade, such as the immunomodulatory and anti-inflammatory agents.

Dual effects of CGRP-antagonist on allergic contact dermatitis in human skin.

There is increasing evidence of an interaction between the nervous and the immune systems. The aim of this study was to investigate the rôle of calcitonin gene-related peptide (CGRP) in the modulation of the elicitation of immediate and delayed, immunological and non-immunological reactions in human skin. CGRP (13 pmol and 39 pmol), and the CGRP-antagonist, CGRP/8-37/, (50 pmol and 500 pmol) were injected intracutaneously prior to provocation tests. Patients with allergy to nickel were provoked with nickel sulfate epicutaneously, and the reactions were evaluated by a clinical scoring system (guidelines of the International Contact Dermatitis Research Group). Patients with allergy to birch pollen were provoked by a prick test with the allergen, and the volume of the weals was measured. The patients were also provoked with tuberculin (delayed immunologic reaction), benzalkonium chloride (irritant contact dermatitis), UV-light and benzoic acid (non-immunologic contact urticaria). The test reactions were estimated by planimetry. CGRP/8-37/ exerted dual effects on allergic contact dermatitis, causing potentiation at a dose of 500 pmol (p= 0.004) and inhibition at a dose of 50 pmol (p=0.012). Other reactions were not significantly affected by the pretreatments. The results suggest that CGRP participates in delayed inflammatory reactions, but is not involved in immediate immunologic reactions.

Barrier recovery and influence of irritant stimuli in skin treated with a moisturizing cream.

Moisturizers are used daily by many people to alleviate symptoms of clinically and subjectively dry skin. Recent studies suggest that certain ingredients in creams may accelerate the recovery of a disrupted barrier and decrease the skin susceptibility to irritant stimuli. In the present single-blind study, a moisturizing cream was tested for its influence both on barrier recovery in surfactant-damaged skin and on the susceptibility of normal skin to exposure to the irritant sodium lauryl sulphate (SLS). Parameters measured were transepidermal water loss (TEWL) and skin corneometer values, indicating degree of hydration. Treatment of surfactant-damaged skin with the test cream for 14 days promoted barrier recovery, as observed as a decrease in TEWL. Skin corneometer values also normalized more rapidly during the treatment. In normal skin, use of the test cream significantly reduced TEWL after 14 days of treatment, and irritant reactions to SLS were significantly decreased. Skin corneometer values increased after only 1 application and remained elevated after 14 days. In conclusion, the accelerated rate of recovery of surfactant-damaged skin and the lower degree of SLS-induced irritation in normal skin treated with the test cream may be of clinical relevance in attempts to reduce contact dermatitis due to irritant stimuli.

The efficacy of a moisturizer (Locobase) among cleaners and kitchen assistants during everyday exposure to water and detergents.

Workers exposed to various irritants are widely advised to use moisturizers. To evaluate the efficacy of a moisturizer (Locobase), we studied 111 cleaners and kitchen workers during everyday exposure to water and detergents. All took part in a standardized interview. After randomization, 1/2 the workers (n = 56) used Locobase during a period of 2 weeks (period L), followed by a period without any emollient (period C), or vice versa (n = 55). Clinical assessment and measurements of the skin surface temperature, electrical capacitance and transepidermal water loss (TEWL) were performed on the fingers, hands and arms on entry to the study, after 2 weeks and 4 weeks, or at drop out. The final evaluation showed that 70 (63%) were able to complete the study; 23 (21%) completed period L, but withdrew from period C after a mean of 6 days because of progressive dryness of the skin and eczema; and 12 (11%) were excluded because they used topical corticosteroids or emollients. The remaining 6 (5%) participants were lost to follow-up. Clinically, we observed a significant increase in dryness (p < 0.001) during periods of no treatment (period C), and normalization of the skin texture during use of Locobase. Clinical observations were confirmed by statistically significant differences (p < 0.001) in the electrical capacitance (epidermal hydration), which decreased during period C and increased to pre-study values during period L. No significant differences were found in skin temperatures and TEWL rates.(ABSTRACT TRUNCATED AT 250 WORDS)