Delayed contact sensitivity

The hypothesis of skin-associated lymphoid tissues [SALT] was built with the evidences obtained by several research centers which investigated contact sensitivity, delayed-type hypersensitivity, tumor subcutaneous transplantation, and skin transplantation [4-8] as it follows. 

Topical formulations are another special case. Over time, it has been shown that the minipig has a skin structure that is quite similar to humans, and that species is now used commonly as the nonrodent model. These types of formulations also require local irritation studies where guinea pigs are used to determine delayed contact sensitization. Selection of the animal species for the nonclinical program is often not straightforward. 

Poison ivy, poison oak Delayed contact sensitivity (allergic dermatitis)... 

Acute dermal application of dilute or full-strength DCP rapidly produced erythema and edema in rats, rabbits, and guinea pigs. Delayed-type hypersensitivity reactions and contact sensitization have also been reported in guinea pigs and humans. ... 

Immunological/Lymphoreticular Gn Pig 24 hr (Hartley) 0.05% F (moderate delayed contact sensitivity) Matsushita et al. 1985... 

There are two main sensitization reactions-immedi-ate and delayed hypersensitivity. Immediate type hypersensitivity is the result of antibody-allergen interaction occurring in the skin the reaction that develops is known as allergic contact urticaria. Delayed type hypersensitivity is the result of cell-mediated immunity and is the most frequently reported side effect of topical drugs. Both epidermal and dermal cells play pivotal roles in irritation and sensitization. Keratinocytes... 

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... 

With regard to skin toxicity, CR produces a transient erythema however, it does not induce vesication and contact sensitization or delay the healing of skin injuries. ° The burning sensation on exposure to CR persists for 15 to 30 min, and erythema may last for 1 to 2 h. 

Cushman and Street (1983) produced IgE antibody in BALB/c mice to a metabolite of malathion conjugated to keyhole limpet hemocyanin. However, cpicuianeous malathion did not elicit a delayed-type hypersensitivity response up to 1 month later. High doses of dithiocarbamates (maneb, mancozeb, and zineb) caused contact sensitization in guinea pigs cross-sensitization among these chemicals was also shown (Matsushita er (., 1976),... 

A transient erythema (1-2 h) occurs, but CR does not induce inflammatory cell infiltration, vesication, or contact sensitization, and it does not delay the healing of skin injuries.24,48 The potential for eye damage is also significantly less than it is from CS or CN.24 CR was neither teratogenic nor embryo-lethal in one study49 when given as an aerosol or by gavage. 

Epstein, W. L., and A. M. Kligman Transfer of allergic contact-type delayed sensitivity in man. J. invest. Derm. 28, 291—304 (1957). 

The ability of occupational agents to produce immediate contact reactions must be specifically investigated, as has been the case for delayed-type contact sensitizers. Studies on the mechanisms of immediate contact reactions, development of appropriate models and standardization of diagnostic tests constitute a challenge for further research. 

The intensity of exposure, i.e., dose, duration, frequency and total area of exposure, is crucial not only for irritant but also for allergic contact dermatitis. Delayed hypersensitivity is a dose-related phenomenon. There is a threshold surface concentration of the allergen required to induce sensitization and/or elicitation of the response [56, 57]. Besides the intrinsic hazardous potential of the substances and intensity of exposure, we have to consider simultaneous exposure factors that might enhance the penetration of the hazardous substance and are unique to the workplace or task, i.e., wet work, occlusion, temperature, humidity and mechanical trauma. 

Jolanki R, Alanko K, Pfaffli P, Estlander T, Kanerva L (1997) Occupational allergic contact dermatitis from 5-chloro-i-methyl-4-nitroimidazole. Contact Dermatitis 36 53-54 Kanerva L, Estlander T, Jolanki R (1994) Occupational skin allergy in the dental profession. Dermatol Clin 12 517-532 Kanerva L, Alanko K, Estlander T, Sihvonen T, Jolanki R (1997) Occupational allergic contact urticaria from chloramine-T solution. Contact Dermatitis 37 180-181 Keller K, Schwanitz HJ (1992) Combined immediate and delayed hypersensitivity to mezlocillin. Contact Dermatitis 27 348-349 Kellett JK, Beck MH (1984) Contact sensitivity to chloroquine sulphate. Contact Dermatitis 11 47 Klijn J (1984) Contact dermatitis from spironolactone. Contact Dermatitis 10 105... 

Allergic contact dermatitis is a delayed hypersensitivity reaction.30 Upon initial exposure, a substance penetrates the skin, binds to a protein and develops into sensitizing antigens. Subsequent exposures to that substance will then elicit an allergic reaction.25,29,30 Symptoms of allergic contact dermatitis are similar to those of the irritant type, but may take several hours to several days to develop following re-exposure.25,26... 

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