Paranitrosodimethylaniline PNDMA Followed by Dinitrochlorobenzene DNCB

We treated 18 guinea pigs to PNDMA (technique p. 28). Nine animals were strongly sensitized (positive patch test) and 9 were weakly or not at all sensitized, despite further sensitizing applications (patch test negative or questionable). 

We then sensitized the 18 guinea pigs to DNCB (see technique p. 4). 

On the contrary, histological examination of the nipple shows many more lesions in the first group (numerous spongiosis and significant infiltrate) than in the second. 

it seems that animals poorly sensitized to PNDMA would be less capable of being sensitized to DNCB than those who initially are well sensitized with the first eczematogen (PNDMA). 

Macroscopic results on the flank and histological results on the nipple would confirm the clinical observations in man that certain individuals possess a greater capacity to beingsensitif ed than others (eine Ekf(embereitschaft Bloch, 1923j. 

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