Disinfectants skin tests

One hundred-sixty-seven doctors, 92 dentists, and 333 nurses were patch-tested with a standard panel of allergens plus allergens common to their work environment. Among nurses, formaldehyde was the disinfectant that most frequently caused allergic reactions (9.6%). Three doctors also had positive skin tests for formaldehyde. 

Respiratory Asthma due to tosylchloramide (Chloramine T) has been reported in a 43-year-old male nurse, who noticed asthmatic reactions after exposure to the disinfectant [25" ]. A skin test with tosylchloramide was positive and an inhalation test with 0.5% caused a significant biphasic reduction in FEVi an inhalation test with glu-taral (glutaraldehyde), to which he had also been exposed, was negative. 

Whereas tests (186) indicated that ampholytes were effective in skin cleansing for preoperative use, for wound cleansing, and as an antiseptic in the oral cavity (187), as well as other medical appHcations, the food and beverage industries have proved to be the principal employers of these compounds. Ampholytes are used as sanitizers and disinfectants, not as food preservatives. Low toxicity, absence of skin irritation, and noncorrosiveness, along with antimicrobial activity, has given ampholytes acceptance in dairies, meat plants, and the brewing and soft drink industries. These disinfectants have been manufactured and distributed in Europe and Japan, but not in the United States. 

In all antiseptic testing, it is recognized that skin and mucous membranes to which products ate appHed cannot be disinfected or sterilized but it is possible to significantly reduce the population of transient and resident pathogenic bacterial flora. AH in vivo test methods requite a deterrnination of the bacteria on the skin before and after treatment. Because of the normal variation in bacterial population of the skin of different people, a number of people must be tested in order to make a statistical analysis of the results. Different parts of the body are used for different tests. In aH of the tests the details of the protocol ate extremely important and must be strictly adhered to in order to obtain reproducible results. 

Many derivatives of phenol are now made by a synthetic process. Homologous series of substituted derivatives have been prepared and tested for antimicrobial activity. A combination of alkyl substitution and halogenation has produced useful derivatives including clorinated phenols which are constituents of a number of proprietary disinfectants. Two ofthe most widely used derivatives are/ -chloro-m-cresol (4-chloro-3-methylphenol, chlorocresol, Fig. 10.7C) which is mostly employed as a preservative at a concentration of 0.1%, and / -chloro-m-xylenol (4-chloro-3,5-dimethylphenol, chloroxylenol. Fig. 10.7C) which is used for skin disinfection, although less than formerly. Chloroxylenol is sparingly soluble in water and must be solubihzed, for example in a suitable soap solution in conjunction with terpineol or pine oil. Its antimicrobial capacity is weak and is reduced by the presence of organic matter. 

Tests considered above have all been conducted in artificial or laboratory conditions. This may be satisfactory when disinfectants are required to act in non-living environments. However, many antibacterials are used on living tissue and on the skin, and so tests to evaluate them in these situations are called for. 

It is possible to also test semi-solid antibacterial preparations on the skin itself, as described for liquid disinfectants (section 3.5.1). A portion of the skin— the backs of the fingers between the joints is a useful spot— is treated with the test organism, the preparation is then applied and after a suitable interval the area is swabbed and the swab incubated in a suitable medium. Alternatively, the method employing pig skin, described in section 3.5.1, may well be adapted to the problem of testing semi-solid skin disinfectants. 

When chlorhexidine was used as a skin disinfectant in a 53-year-old man undergoing lung resection for adenocarcinoma, anaphylaxis was complicated by coronary artery spasm (47). He had two anaphylactic reactions accompanied by severe myocardial ischemia. Immunological testing indicated chlorhexidine as the causative substance. 

Simulated use tests involve deliberate contamination of instruments, inanimate surfaces, or even skin surfaces, with a microbial suspension. This may either be under clean conditions or may utilize a diluent containing organic (e.g. albumin) material—dirty condition. After being left to dry, the contaminated surface is exposed to the test disinfectant for an appropriate time interval. The microbes are then removed (e.g. by rubbing with a sterile swab), resuspended in suitable neutralizing medium, and assessed for viability as for suspension tests. New products are often compared with a known comparator compound (e.g. 1 minute application of 60% v/v 2-propanol for hand disinfection products— see EN1500) to show increased efficacy of the novel product. 

B Price. The bacteriology of normal skin a new quantitative test applied to a study of the bacterial flora and the disinfectant action of mechanical cleansing. J Infect Dis 63 301-318, 1938. 

Uses Intermediate for chemical synthesis test reagent for analysis of fiber mfg. pharmaceuticals, medicines (removal of skin lesions as a disinfectant)... 

Quaternary ammonium compounds are cationic detergents. They are used as preservatives in cosmetic and medical topical products and also as a disinfectant for the skin (for instance, preoperative skin cleaning). It is also known as an algaecide (wood preservative, some marine paints). Patch-test concentrations range from 0.01% to 0.1% aqua. Patch testing with 0.1% aqua easily provokes irritant reactions true allergic responses are also obtained with 0.01% aqua. Crossreactions between the quaternary ammonium compounds are frequently seen. 

Cidex is 2% acidic glutaraldehyde, a stable solution, but when activated (by means of buffering the solution with sodium bicarbonate to a pH of 7.5-8.0), it has a relatively strong irritant effect on the skin. When used as a hospital disinfectant, it is considered an occupational hazard (Hasen 1983). The patch-test concentration is 1% pet. Allergic reactions are uncommon (Nethercott et al. 1988). Cross-reaction with formaldehyde is possible. 

Mercury chloride (mercuric chloride, CAS no. 7487-94-7) was once a classical disinfectant, but has fallen into disuse because of its high toxicity and sensitization index. It is a caustic compound and therefore also a potent skin irritant (erythema, follicular pustules and papules). The patch-test concentration is 1% pet. Allergic reactions do occur. 

Direct skin contact of the veterinarian with animal medications has probably diminished since the 1970s in many countries. Antibiotics (and other medications) used in veterinary medicine and also animal feed are mainly the same as in human medicine, e.g., penicillins, cephalosporins, macrolides, tetracyclines, quinol-ones, sulfas, trimethoprim, antifungals. In addition, other substances have been used in animals only, e.g., penethamate, tylosin, spiramycin, furazolidone. Many antimicrobials are contact sensitizers and may cause contact dermatitis at low concentrations. No routine series for patch testing can be recommended because of the risk of active sensitization. Patch testing should be done with the particular medications with which the veterinarian has been in contact directly or via fodder. Contact urticaria from several antibiotics and disinfectants has also been reported (Hannuksela 1997b Kanerva 1997). 

Level 3 refers to practical use tests. They are performed in suspension, on specific nonliving surfaces, or on skin, and they allow characterization of effectiveness of a disinfectant product for a particular claimed use. For each of the above three categories, these tests m e use of the same sfiains as the suspension tests. 

Other Cresol-type Disinfectants and Antiseptics. Various non-irritant germicides of low toxicity, and therefore particularly suitable for disinfecting the skin and for application to wounds, contain different amounts of chloroxylenol, dichloroxylenol, benzyl cresols, o-phenylphenol, chloro-benzylphenols, special narrow-range boiling fractions of coal tar distillates, etc. They are usually dissolved in a soap, such as castor oil soap, and essential oil solution as they are only sparingly soluble in water. The various phenol coefficient tests, and particularly the Chick-Martin test, are of value in standardising such preparations, but they are of little value in determining their practical efficacy as antiseptics. For such purposes, other more specific tests are required which are beyond the scope of this book. 

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