Hi,
on another forum (hairlosshelp ) there has been a discusision
on this. seach for the word inflammation there.
i too have some pimples on my scalp. it could be caused by
slightly excess use of nizoral. so try to slow it down for a while,
apply aloe vera (or hydro-cortisone in an extreme case)
and hopefully the pimples will stop (it hasn't for me yet)
applying some oils like cocunut oil, tea tree/lavender/emu
leaving it in for an hour or so and then washing it off
with nizoral might also help.
also consider anti-inflammatories like turmeric extract,
aspirin.
hope this helps.