Skin susceptibility

Duval, D., Lindberg, M., Boman, A., Johansson, S., Edlund, F., and Loden, M., Differences among moisturizers in affecting skin susceptibility to hexyl nicotinate, measured as time to increase skin blood flow, Skin Res. Technol., 8, 1, 2002. 

Loden, M., Barany, E., Mandahl, P., and Wessman, C., The influence of urea-treatment on skin susceptibility to surfactant-induced irritation. A placebo-controlled and randomized study, Exogenous Dermatol., 1, 3, 2004. 

Determination of basal biophysiological parameters may identify subjects with sensitive skin. Earlier studies have shown that increased skin susceptibility has been correlated with an increased basal TEWL, 1 41 skin surface pH,42 and fair skin complexion (measured by chromametric L values),43 whereas no relationship was shown for basal skin thickness, skin blood flow, sebum excretion, and skin hydration.29 However, a recent study by Seidenari et al. utilizing multiple bioengineering techniques showed significant correlations only for capacitance and colorimetric a values.44... 

Poisons usually enter a body through the mouth or nose, but some substances may be absorbed through the skin. Susceptibility to poisons depends on an organism s individual characteristics, such as age, mass, past history, general health, and body chemistry. Some toxins, such as lead, mercury, and arsenic, can accumulate in the body and may cause problems over a long period of time. 

Agner T (1991a) Skin susceptibility in uninvolved skin of hand eczema patients and healthy controls. Br J Dermatol 125 140-144... 

The identification of risk groups for occupational skin diseases depends on skin exposures at the workplace, the individual s specific and nonspecific skin susceptibility, and the quality and use of protective equipment and barrier creams. The daily duration of wet work, working with dry irritants (grinding dusts) or the wearing of occlusive protective gloves for 2 h and more, the necessity and frequent cleaning of the hands (more than 20 times) or the unavoidable direct skin contact to potent sensitizers represent the most relevant burden-associated risk marker. Individual... 

Held E, Agner T. Effect of moisturizers on skin susceptibility to irritants. Acta Derm Venereol. 2001 81 104-7. 

Experiments involving the use of dimethyl sulphate should be carried out by students only under immediate supervision. Not only is the vapour of dimethyl sulphate highly poisonousy but the cold liquid itself is absorbed easily through the skin, with toxic results individual susceptibility to ditnethyl sulphate poisoning varies and may be very high. If the sulphate is splashed on to the hands, wash immediately with plenty of concentrated ammonia solution in order to hydrolyse the methyl sulphate before it can be absorbed through the skin (see p. 528). 

Most of them are generally classified as poisons. Exceptions to this rule are known. A notable one is 4-dimethyl aminopyridine (DMAP) (24), which is widely used in industry as a superior acylation catalyst (27). Quaternary salts of pyridines are usually toxic, and in particular paraquat (20) exposure can have fatal consequences. Some chloropyridines, especially polychlorinated ones, should be handled with extra care because of their potential mutagenic effects. Vinylpyridines are corrosive to the skin, and can act as a sensitizer for some susceptible individuals. Niacin (27), niacinamide (26), and some pyridinecarbaldehydes can cause skin flushing. 

The toxicity of a few boric acid esters has been summarized (30). In general the toxicities are directiy related to the toxicity of the alcohol or phenol produced on hydrolysis. Methyl borate has an oral rat LD q of 6.14 mL/kg in a range finding test (31) and the percutaneous LD q for the rabbit of 1.98 mL/kg. In eadier work (32), the oral LD q for the rat was 2.82 mL/kg the intraperitoneal LD q was 3.2 mL/kg. It has been shown that the mouse is more susceptible to these compounds than the rat. Methyl borate was found to be moderately irritating in an ocular toxicity test using rabbits (31,32) but only mildly irritating to skin (31). 

Local repair of delamination originally caused by non-durable surface treatment is only temporarily successful at best. The surface treatment on the unrepaired portion of the assembly remains susceptible to attack and the area of delamination will likely continue to grow once the assembly is put back into service and exposed to moist conditions. Replacement or complete remanufacture of the component is the only way to permanently address this type of damage. However, time-limited repairs using bonded or mechanical methods can be used to extend the life of the component until a major overhaul is scheduled. In some cases such as widespread disbond of fuselage doublers, mechanical repairs (rivets and fastened doublers) and continued inspection are used to extend the life of the skin indefinitely because of the high cost of replacement. 

Machine operators working with emulsions can become susceptible to skin infections because of the combination of the de-fatting effect of soluble-oil emulsifiers and the abrasive action of metallic scarf, but bacteria in cutting fluids are seldom the source of such infections. High standards of personal hygiene and the use of barrier creams should prevent such problems. A more difficult situation arises when a soluble-oil emulsion becomes infected with bacteria capable of utilizing the emulsifier and mineral-oil components in the system. Even in clean conditions, untreated soluble-oil emulsions and solutions cannot remain completely sterile for any length of time. 

The fluoroquinolones are used in the treatment of infections caused by susceptible microorganisms. The fluoroquinolones are effective in the treatment of infections caused by gram-positive and gram-negative microorganisms. They are primarily used in the treatment of susceptible microorganisms in lower respiratory infections, infections of the skin, urinary tract infections, and sexually transmitted diseases. Ciprofloxacin, norfloxacin, and ofloxacin are available in ophthalmic forms for infections in the eyes. 

Griseofulvin is adminisfered orally in the form of tablets. It is not totally absorbed when given orally, and one method of increasing absorption is to reduce the particle size of the drug. Griseofulvin is deposited in the deeper layers of the skin and in hair keratin, and is therefore employed in chemotherapy of fungal infections of these areas caused by susceptible organisms. 

The antimicrobial activity of iodine is less dependent than chlorine on temperature and pH, though alkaline pH should be avoided. Iodine is also less susceptible to inactivation by organic matter. Disadvantages in the use of iodine in skin antisepsis are staining of skin and fabrics coupled with possible sensitizing of skin and mucous membranes. 

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