Sensitization with Citraconic Anhydride CA

We observe spongiosis on the nipple even if we do not observe it on the flank of the same guinea pig. It is surprising that we did not find similar lesions in both the flank and nipple. This shows that the lesions do not always evolve in the same manner on the flank and nipple (N. Hunziker, 1962). 

To summarize in guinea pigs sensitif ed to PNDMA, the macroscopic test is generally distinct whereas, histological examination yields a great variability in the epidermal as well as in the dermal lesions. 

In 1940, Jacobs, Jacobs and coll, described experiments with different anhydrides, one of which was citraconic anhydride. Their attention had been attracted by a case of asthma in a chemist described by Kern (1938/39) the asthma, however, was not due to citraconic anhydride but to phthalic anhydride. 

Citraconic anhydride provokes specific reactions in sensitized guinea pigs (Jacobs Jacobs and coll., 1940) an immediate urticarial reaction after 30 minutes, then a delayed reaction after 6 to 8 hours which subsequently disappears in a few days. The immediate reactions were occasionally accompanied by a generalized rash. 

Sensitivity of guinea pigs to CA was also observed by Chase (1954) however, no histological examination was performed. 

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