Patch test evaluation

Sporadic cases of dermatitis due to primary irritation by a-chloroacetophenone have been reported. Allergic contact dermatitis to this substance in chemical Mace has been documented by patch test evaluation, and it is said to be a potent skin sensitizer. ... 

Photosensiti2ation, the potential of a product to cause sensiti2ation in the presence of sunlight, is similarly evaluated by taking a patch test on guinea pigs before and after exposure to uv radiation (141). 

The further allergologic workup is recommended should be performed within 6 months after the reaction [13]. Both delayed IDTs and patch tests are frequently positive, when read after 48 and 72 h (in case of local pruritus or erythematous plaques optionally at other time points, e.g. 24 h, 96 h). Since some patients tested positive with only one of these tests, it is recommended to use both tests in parallel to enhance test sensitivity (table 3). Patch tests should be conducted with undiluted RCM, whereas 10-fold diluted products in physiologic saline had been recommended when performing delayed IDTs. IDTs and late readings with undiluted RCM may be discussed in non-severe reactions to increase sensitivity, however this has not been evaluated in a sufficient number of controls. A panel of several different RCM should be tested to identify skin test-negative substances. 

Only a few in vivo dermal toxicity studies have been reported so far. Huczko and Lange [50] evaluated the potential of raw CNTs to induce skin irritation by conducting two routine dermatological tests (patch test on 40 volunteers with allergy susceptibilities and Draize rabbit eye test on four albino rabbits). Koyama etal. [51] showed the biological responses to four different types of carbon nanotubes (SWNTs, two types of MWNTs with different diameters, and cup-stacked carbon nanotubes) after their subcutaneous implantation in mice. Both tests [50, 51] showed no or poor irritation effects. However, the in vitro studies in epidermal cell lines exposed to CNTs, and also a more recent report on the toxic outcomes of topical exposure of mice to SWNTs [46], have raised concerns over these assessments. Clearly, this is an area requiring further scientific evaluation. 

Table 1.1 Magnusson/Kligman grading scale for the evaluation of challenge patch test reactions [130],...

Hemmer W, Wantke F, Focke M, et al. 1996. Evaluation of cutaneous hypersenstivity to aluminum by routine patch testing with A1C13. Contact Dermatitis 34 217-218. 

Gammelgaard, B., Fullerton, A., Avnstorp, C., and Menne, T., In vitro evaluation of water and petrolatum as vehicles in chromate patch testing, Contact Dermatitis, 27, 317, 1992. 

In contrast, the basis of cleanser testing has historically been about evaluating dryness and irritation potential. Since 1979 when Frosh and Kligman published a seminal paper on the soap-chamber patch test, cleanser moisturization and mildness have been defined as reduced dryness and damage in comparison to soap.43 As Wolf points out, for decades the desired qualities for soap have... 

York, M., Griffiths, H.A., Whittle, E., and Basketter, D.A. Evaluation of a human patch test for the identification and classification of skin irritation potential. Contact Dermatitis 1996 34 204—212. 

In the Draize human sensitization test, an occlusive patch containing the test material is applied to the upper armor upper back of 200 volunteers. The patch remains in place for 24 h and is then removed. The test site is evaluated for erythema and edema at patch removal. Twenty-four hours after the removal of the 1st patch, a 2nd patch test is applied. This... 

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... 

It is possible to conduct predictive irritation assays in man as only a small area of the skin needs to be tested (provided that systemic toxicity is low and informed consent is obtained). Patch test responses generally heal rapidly, within a week or so. More severe reactions should be evaluated periodically over a longer period to determine how the inflammatory response is resolved. Some subjects may develop changes in pigmentation level at the test site following severe responses. It... 

PURPOSE AND RATIONALE Inflammation produced late in the induction phase of sensitization tests without positive responses at challenge is cumulative irritation. The HRIPT for skin allergy was modified to evaluate skin irritation. As with single-application patch tests, many investigators developed their own version of the repeat application patch test. 

In Japan, Uchiyama has recently published requirements for the safety evaluation of new excipients. These requirements include studies on acute, subacute, and chronic toxicity, mutagenicity, effects on reproduction, dependency, antigenicity, carcinogenicity, and local irritation (human patch test). The first five of these tests are mandatory. With the exception of the local irritation test, for which a domestic trial is required, non-Japanese data are acceptable for these studies. Even if a material has been used in a pharmaceutical product outside Japan, the material is treated as a new excipient if there has been no prior use in Japan, although relevant overseas data for the material are acceptable for regulatory submission. A material is treated as a new excipient when the route of administration differs or the dose level exceeds that of prior use even after approval for the Japanese market.f ... 

The incidence of contact sensitization associated with topical formulations containing plant extracts was significant when evaluated in 1032 consecutive or randomly selected patients visiting patch test clinics in The Netherlands (27). 

Futrell JM, Rietschel RL. Spice aUergy evaluated by results of patch tests. Cutis 1993 52(5) 288-90. 

Topical polymyxin B was the predominant allergen in patients who underwent patch-testing for evaluation of eczema of the external ear canal (22). 

Brenan JA, Dennerstein GJ, Sfameni SF, Drinkwater P, Marin G, Scurry JP. Evaluation of patch testing in patients with chronic vulvar symptoms. Australas J Dermatol 1996 37(l) 40-3. 

There are several acceptable ways to evaluate DTH responses in nonclinical species. Of these, the most common are the guinea pig assays used to assess contact sensitization. Both the Magnusson and Kligman model (guinea pig maximization test) and the Buehler model measure the elicitation phase of the hypersensitivity response, though the tests vary in their methods of chemical application and utilization of adjuvants. Most recently, the local lymph node assay has been accepted as a stand alone test for chemical hypersensitivity. This assay is conducted in mice and measures the induction phase of sensitization. In humans, the most common methods to assess delayed hypersensitivity are the patch test (contact sensitivity for diagnostic purposes) and the human repeat insult patch test (contact sensitivity for predictive purposes). Additionally, intradermal... 

Many industries regularly conduct repeat insult patch tests on human volunteers to evaluate topical irritancy. Groups of human volunteers are patched with test substance. One to five concentrations can be tested simultaneously, a wide enough range to yield results relevant to the usage. Cumulative skin irritancy is measured by applying patch applications each day for 3 weeks. Skin irritation is usually assessed visually, but blood flow and skin temperature can be measured objectively by laser Doppler flowmetry, ultrasound Doppler, heat flow disk measurement, sensitive thermocouple devices, or noncontact infrared radiative techniques. In these tests, dose-response curves can be obtained. Skin thickness can be measured with calipers as a measure of edema formation. 

The detailed history and examination of the patient s skin is necessary for the diagnosis of occupational skin disease, in most cases followed by patch testing. Further investigations and visits to the workplace may be necessary. Observation of symptoms after returning the patient to the same workplace is important. Evaluation has the following objectives ... 

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