Sensitive skin identification

The use of Dimethyl sulphoxide (DMSO) in dermatology has a long history.18,19 In concentrations up to 50% DMSO is used for topical treatment of amyloidosis,20 but in concentrations of 90% and higher it is known to induce whealing and a flare reaction. The procedure described here is a modification of that described by Frosch et al.21 for the identification of individuals with sensitive skin. The DMSO reaction can be assessed clinically or measured with the laser Doppler flowmeter.22 The recent development of laser Doppler imagers28 make it possible to measure the DMSO induced increase in blood flow with unparalleled accuracy. To elicit the reaction 15 /ul of 90%, 95%, and 100% DMSO were applied to three adjacent sites and immediately covered with a circular plastic disc,... 

Identification of a Sensitive Skin Panel Marie C. Marriot and Al. in Sensitive Skin Syndrome by Enzo Bertardesca, Joachim W. Fluhr and Howard I. Maibach. Taylor and Francis Edition 2006... 

From such investigations, the exposure concentration or dose is often unknown and thus, a dose-effect relationship is difficult to evaluate. Therefore, information from clinical and physiological investigations generally has a limited use in the hazard assessment exceptions are identification of skin sensitizers and indications of possible adverse effects to selected organs and tissues depending on the investigations performed. 

The WHO/IPCS international workshop on skin sensitization in chemical risk assessment (WHO/IPCS 2007) concluded No in vitro assay systems for identification of skin sensitizing... 

The WHO/IPCS international workshop on skin sensitization in chemical risk assessment (WHO/IPCS 2007) concluded (Q)SARs and expert systems for identification of sensitizing capacity have not been vahdated to date, but may be used as part of a weight of evidence approach for identifying the sensitizing capacity of chemicals. There are certain local (Q)SARs that can be used for a small range of chemicals. However, these are currently insufficient to cover the full range of chemicals. The Workshop recommended that QSAR models need to be further developed, and the apphcabihty domain of each model needs to be established. ... 

Predictive identification of human skin sensitization thresholds. Contact Dermatitis, 53, 260-267. 

Ryan, C.A., Kimber, 1., Basketter, D.A., Pallardy, M., Gildea, L.A. and Gerberick, G.E. (2007) Dendritic cells and skin sensitization biological roles and uses in hazard identification. Toxicology and Applied Pharmacology, 221, 384—394. 

This test using animals seems to be the most frequently used predictive test for the identification of skin-sensitizing chemicals or for chemicals prone to cause allergic contact dermatitis. While it is most frequently used for general dermatological investigations, results... 

Evaluation must distinguish between primary irritation responses, which may disappear within a couple of days, and sensitization responses which may develop more slowly, persist longer, and are characterized by pruritis, erythema, edema, papules, vesicles, bullae, or a combination of these. Further identification of sensitization reactions may involve microscopic examination of skin biopsy samples. Some issues which may be encountered in human studies include reactions early in the induction phase which may be indicative of preexisting sensitization to the test material, or a delayed response at 192 h instead of at 48 or 96 h. Follow-up of subjects not completing the study may yield valuable information on the adverse effects of a preparation. 

However, hazard identification alone does very little to protect human health—it is only the start of the process. When a chemical has been identified as a potential skin sensitizer, then unless it is banned from use, the risk that it presents must be assessed and managed. To achieve this, it is vital to characterize the relative potency of the identified sensitizer, not least since the currently available evidence indicates that this may vary over perhaps five orders of magnitude [25, 26]. As mentioned earlier, this has been successfully achieved using the LLNA EC3 value [27-34], Consequently, various workers have begun to compare the predictions from in vitro methods to this potency measure (e.g., [82, 85]). It would be preferable though to develop predictive systems in vitro which deliver information on the relative potency of skin sensitizers in humans rather than in mice. To this end, a... 

AD, as some patients do not present with such abnormalities. Skin prick tests or enzyme-linked immunosorbent assay tests can be used to aid in identification and exclusion of allergic triggers, but these are not specific or sensitive enough to be diagnostic. 

B. anthracis are usually used to diagnose anthrax however, previous antibiotic treatment will affect culture yield and Gram stain identification of the bacteria. Immunohistochemistry has demonstrated high sensitivity and specihcity for the detection of B. anthracis in skin biopsies, pleural biopsies, transbronchial biopsies, and pleural fluids (see Fig. 

Initially, LMW inhalation drugs can be screened for their ability to sensitize the immune system. A contact sensitization model, the local lymph node assay (LENA), has been validated for the identification of agents that cause skin sensitization (Kimber et al, 1991). In this model, the test article is prepared in a vehicle, such as olive oil/acetone, and applied to both ears of mice for three consecutive days, and on the sixth day, proliferation in draining lymph node is determined (Gerberick et al, 2000). Test articles that produce a stimulation index greater than three times vehicle control are considered positive contact sensitizers. To date, most if not all LMW respiratory sensitizers tested... 

Gildea LA, Ryan CA, Foertsch LM, Kennedy JM, Dearman RJ, Kimber I, Gerberick GF. Identification of gene expression changes induced by chemical allergens in dendritic cells opportunities for skin sensitization testing. J Invest Dermatol 2006 126 1813-1822. 

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