In the production of numerous dermatoses the streptococcus plays either a preponderant or an accessory rôle. In the one case, lesions result from the direct inoculation of the sound skin, giving rise to what may be considered a pure streptococcic dermatosis. In the other case, various complexes follow the inoculation of an antecedent affection, with the streptococcus either alone or in association with another organism.
As to what reactions may be properly classified as streptococcic in the strict sense, there is probably some divergence of opinion. Of course the simple occurrence of the organism in a lesion does not entitle it to be labeled one of the pure streptococcic dermatoses. To be fairly included in such a category, definite etiologic relationship must be established.
On the other hand, the presence of the streptococcus in a given case, even as an accessory, may be of greater practical importance than the question