Skin responsiveness

The classical skin response to local release of histamine that results from contact with an allergen, irritant or following an insect bite. A central wheal develops as a direct result of local inflammation and the the oedema the follows the increased capillary permeability caused by histamine acting on HI-receptors on vascular-endothelial cells. 

PARABEN ESTERS Typical use concentrations 0.1 - 0.3% Low toxicity Dermatologically safe at typical use concentrations Over 70 years widespread use with an extremely low incidence rate of skin response GRAS (Generally Recognised As Safe) in the USA Stable and active over a wide pH range Stable to heat Combinations of esters exhibit increased activity Approved for cosmetic applications worldwide Low water solubility Some nonionics inactivate to varying degrees May require addition of other preservatives, eg. bactericides Incompatible with some proteins... 

To validate the skin carotenoid RRS detection approach, we initially carried out an indirect validation experiment that compared HPLC derived carotenoid levels of fasting serum with RRS derived carotenoid levels for inner palm tissue sites. Measuring a large group of 104 healthy male and female human volunteers, we obtained a significant correlation (p < 0.001) with a correlation coefficient of 0.78 (Smidt et al. 2004). Recently, we carried out a direct validation study, in which we compared in vivo RRS carotenoid skin responses with HPLC-derived results, using the thick... 

The expanding field of avian immunoecology has provided strong evidence that suppressed immunity leads to ecologically relevant consequences in wild birds. In a review of 12 immune function studies, immune responses were the most significant predictors of subsequent survival of young wild birds [107], In an assessment of 280 introduction attempts in 38 avian species, immunocompetence as assessed by the PHA skin response was an important positive predictor of the ability of birds to colonize new areas (i.e., found new local populations) [108], Similar assessments of survival, fitness, and dispersal ability should be conducted within the context of immunotoxicological studies of wild birds. 

Clothier R, Starzec G, Pradel L et al. (2002) The prediction of human skin responses by using the combined in vitro fluorescein leakage/Alamar Blue (Resazurin) assay. ATLA. 30 493-504. 

Town GI, Holgate ST Comparison of the effect of loratadine on the airway and skin responses to histamine, methacholine, and allergen in subjects with asthma. J Allergy Chn Immunol 1990 86 886-893. 

Clinically unaffected skin in atopic dermatitis differs from normal skin the underlying barrier defect associated in more than 30% with filaggrin loss of function mutations first published in 2006 [4] leads to dry skin associated with a greater irritant skin response than in normal healthy skin. Microscopic studies revealed a sparse perivascular T cell infiltrate in unaffected atopic dermatitis skin that is not seen in normal healthy skin. 

Araujo MI, Lopes AA, Medeiros M, et al Inverse association between skin response to aeroallergen and Schistosoma mansoni infection. Int Arch Allergy Immunol 2000 123 145-148. 

Because adverse skin responses are so easily recognizable, this organ was among the earliest subjected to scrutiny, mostly by physicians interested in occupational diseases. Bernardino Ramazzini s tract of 1700, De Moribis Artificum Diatriba, contained many examples of skin diseases associated with occupational exposures, and, as will be seen in the next chapter, the seminal work of Percival Pott on occupationally induced cancers, published in 1775, revealed the role of soot in the production of cancers on the skin of the scrotum in London chimney sweeps. 

Toxicology. Acute exposure to asphalt fumes causes irritative effects. Certain extracts of asphalt have caused a carcinogenic skin response in experimental animals. 

The most promising alternatives were synthetic pyrethroids. The pyrethroids, developed as derivatives of naturally occurring pyrethrum, cause hyperexcitation, aggressiveness, incoordination, whole-body tremor, and seizures. Acute exposure in humans, usually resulting from skin exposure due to poor handling procedures, usually resolves within 24 hours. While not particularly toxic to mammals, they can cause an allergic skin response in humans. Some pyrethroids may cause cancer, reproductive or developmental effects, or endocrine system effects. 

DAmato, and G. DAmato. Evaluation of serum specific IgE and skin responsiveness to allergenic extracts of Oleaceae pollens (Olea europaea, Frax-inus excelsior and Ugustrum vulgare) in patients with respiratory allergy. Allergol Immunopathol (Madr) 1995 23(1) 41-46. 

Fisher,14 discussing tear gases and their effect on human skin, remarked that CS Is a sensitizer and a primary Irritant capable of causing first- and second-degree burns and even ulcers if not washed off the skin. In experimentally sensitized subjects, CS elicited a skin response in one of nine when tested at 0.1%, but none reacted at 0.01Z.2/ Concentration is a factor in the elicitation of a skin response to a sensitizer, as well as an Irritant. 

Wilson DR, Walker SM, Torres Lima M, Durham SR Comparison between injection and sublingual immunotherapy for hay fever Diary scores, skin responsiveness and serum antibodies. J Allergy Clin Immunol 2002 109 S170. 

Hydration studies reveal that drier skin had lowered friction while hydrated skin had an increased amount of friction (Table 32.1). However, the skin response is more complex, because very wet skin also has a lowered friction coefficient much like the characteristics of dry skin.16 Most studies focus on an intermediate zone of hydration where the skin has been moistened without an appreciable slippery layer of water on the skin. Results in Table 32.1 show that the increases in friction were... 

Over the years a panel of methods has been published for testing different properties of the SC barrier (Table 37.1). The combination of tests, employing the application of chemical probes to the skin and the measurement of skin responses with new bioengineering read-out systems allows to measure changes in barrier properties with high sensitivity and reliability. A subjective selection of skin barrier tests will be discussed further in this chapter. 

Bioengineering methods to measure skin responses to chemical probes... 

Muizzuddin et al. recently studied contact urticaria in an attempt to define sensitive skin objectively.22 Skin responsiveness was assessed using balsam of Peru, which induces NICU. They found that individuals with self-assessed sensitive skin were more susceptible to NICU. This group was also more susceptible to stinging induced by lactic acid and stratum corneum barrier removal using tape stripping. 

Van Neste, D. and de Brouwer, B., Monitoring of skin response to sodium lauryl sulfate clinical scores versus bioengineering methods, Contact Dermatitis, 27, 151-156, 1992. 

Opdyke DL, Burnett CM (1965) Practical problems in the evaluation of the safety of cosmetics. Proceedings of the Scientific Section of the Toilet Goods Association 44 3 1 Opdyke D (1971) The guinea pig immersion test A 20 year appraisal. CFTA Cosmetic J 3 46—47 Phillips L, Steinberg M, Maibach HI, Akers WA (1972) A comparison of rabbit and human skin response to certain irritants. Toxicol Appl Pharmacol 21(3) 369-382 Uttley M, Van Abbe NJ (1973) Primary irritation of the skin Mouse ear test and human patch test procedures. J Soc Cosmet Chem 24 217-227... 

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