No, by "sitting in one's own filth", I meant "sitting in one's own filth", i.e., neglecting hygiene in a particularly revolting fashion, but not bothering to do anything about it because one's ability to experience revulsion has been artificially suppressed. Such inaction also, of course, will if protracted enough certainly lead to various skin conditions, verminous infestations, &c. -- but our notional lotus eater won't be bothered by those, either, any more than by the conditions which produce them.