http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2152159/
[quote]The impetigo lesions were unusually circinate in character, so much so in fact as to simulate a tinea to a certain extent, though the fact that the edge showed an even formation of bulla rather than closely set miliary vesicles made me confident that it was not ringworm. I examined part of this blister, and was surprised to find that there were numerous examples of Demodex folliculorum adhering to the epidermis.
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Numerous comedones were then examined and smears from the unaffected skin as he was seborrhoeic, and no demodex was found in these specimens.
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A fourth case was seen soon after which did not show the circinate lesion quite so obviously, and again the demodex was found in the lesion but not elsewhere.
In ordinary impetigo I have been unable to find the demodex.
One of the cases was treated with mild sulphur ointment and was cured in a week. I have not found that sulphur is a good treatment for ordinary impetigo, though I am aware that Unna has claimed that it is. I therefore think that the demodex has an aetiological relationship with the lesion. It may be that it carries the streptococcus into the epidermis, or it may be the actual irritant.
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I have from time to time seen patients who have given a history of a scabby dermatitis of the face, " caught while treating a dog with the mange," but I have not seen the disease in its active state. One form of mange in dogs is accompanied and probably caused by a demodex as far as I know indistinguishable from the human Demodex folliculorum.
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The lesions already described as associated with the demodex, as far as I can ascertain, are: discoloration of the
skin, especially. around the mouth, obstinate acne, rodent ulcer, and epithelioma. I have provisionally named this disease " demodex impetigo."[/quote]