The Mechanism of Contact Sensitisation

Abstract

IT lzas long been known that human skin can be sensitised by contact with simple chemical substances and the patch test of Jadassohn was used as a clinical method to detect this kind of sensitisation. Experimental contact sensitisation in guinea-pigs was produced for the first time in 1928 by means of neosalvarsan (Frei, 1928) soon to be followed by similar experiments with para-phenylenediamine (Mayer, 193 l), phenylhydrazine (Jadassohn, 1930) and primula extract (Bloch and Steiner-Wourlisch, 1930). In a remarkable investigation Bloch and other (1930) demonstrated that the local application of primula extract to guinea-pig skin was followed a few days later by sensitisation of the entire skin. They showed that repeated application of the extract did not produce desensitisation and that the sensitisation could not be transmitted by means of serum or wheal fluid. Earlier (Bloch and Steiner-Wourlisch, 1926) these same workers had shown that a sufficiently large dose of primula extract would sensitise almost 100 per cent of a group of human subjects, thus disposing of the idea that hypersensitivity could be achieved only in a small proportion of "idiosyncratic individuals".Landsteiner and Jacobs (1 935) used substituted benzene derivatives, for example, dinitrochlorobenzene (DNCB) and picryl chloride (PC) to induce contact sensitisation in guinea-pigs, and most of the subsequent work in this field has been carried out with this type of compound. Following the intracutaneous or epicutaneous application of DNCB or PC to guinea-pig skin, a generalised skin hypersensitivity develops on the 5th to the 9th day. If at this stage a second application is made elsewhere on the surface of the skin, a pinkish reaction on a slightly swollen background begins to arise at the second site after a few hours ; this reaction becomes maximal after 24-48 hr. The individual susceptibility of guineapigs towards contact sensitisation varies. Some guinea-pigs cannot be sensitised at all, and strains of markedly different genetic susceptibility have been isolated (Chase, 1941).The main site of the contact sensitisation reaction is in the basal layers of the epidermis. Although there is a superficial resemblance between the primary toxic effect of a large dose of PC and DNCB in a non-sensitised guinea-pig and the effect of a much smaller dose of the same compound in a sensitised guinea-pig the histological character of the lesion in the two instances is different (Jadassohn, Bujard and Brun, 1955 ;de Weck and Brun, 1956;Fisher and Cooke, 1958a). The primary toxic response is characterised by degeneration of epidermal cells with moderate leucocytosis, whilst the allergic response is characterised by a rapid massive extravasation of mononuclear cells migrating in trails directly into the 1

Immune mechanisms of induction and expression of contact hypersensitivity reaction in rats

“…Prvobitna istraživanja kontaktnog dermatitisa vršena su na ljudima, međutim kako ispitivanje potencijala slabih senzibilišućih agenasa zahteva veliki broj ispitanika, a kontakt ispitanika sa hemikalijom može izazvati trajan zdravstveni problem, javlja se potreba za uvođenjem životinjskih modela bolesti. Do 1930. razvijen je model kontaktne preosetljivosti kod zamorčića, koji se zasniva na prvom kontaktu kože sa haptenom usled njegovog intrakutanog ili epikutanog nanošenja (senzibilizacija), i drugog kontakta (elicitacije reakcije) usled nanošenja hemikalije od petog do devetog dana nakon senzibilizacije na bilo koju površinu kože, osim na prvobitno tretirano mesto, nakon čega dolazi do ekspresije reakcije, sa pikom 24-48h nakon elicitacije (Landsteiner i Jacobs, 1935;Schild, 1962).…”