The topic of certain kinds of Ashkenazic Jewish women who shave their head never ceases to fascinate and horrify. The origin of this seems lost in the mists of time. The custom makes its appearance in Jewish literature of the 19th century in defenses of the practice, as well as in a decree of forcible Russification forbidding it in the mid-19th century. Speculations about its origin range from it being caused by external forces (some sort of attempt at warding off marauding lords or Cossacks who raped Jewish women) to internal ones (some sort of extra stringent approach to mikva, perhaps decreed by the early modern Council of the Four Lands). No evidence, as far as I can tell, exists for either theory. My own provisional theory is that it may have evolved from some sanitary need, perhaps occasioned by the practice of married Jewish women to always keep their head covered, and whatever might have bred underneath such perpetual coverings in those less sanitary times; see below. But who knows?
In any case, I came across something interesting:
Although this excerpt is from a later reprinting, this is part of a poem which appeared in the October 1783 issue of the London Magazine.
Secondly, in 1790 the medical researcher Mastallir published a book called "Praktiche Abhandlung uber den Wichtelzopf," or "A practical Treatise on the Plica Polonica," which is a nasty dermatological condition (I think that anyone who ever wondered about Rabbi Aharon Leib Steinman's beard should have a look at that Wikipedia link). Mastallir reviewed four case studies, including one Jewish woman who had no hair on her head, but "was attacked in another part."
Also, the following appeared in an 1853 issue of the British humor mag Punch:
More forthcoming, if there's any relevant info to uncover, so to speak.