So at the end of January the thing I thought was a blister at the bottom of my back turned out to be a cyst, when it developed an abcess and burst in a shower of blood and icky looking matter. Medical advice was sought, antibiotics were prescribed and a dressing was applied.
Three and a half weeks, several dressings, three checkup visits and three courses of antibiotics later it's still emitting dark coloured tissue matter. That's not normal, is it, in terms of how long before it should have drained? The district nurse told me it was quite common among men to have one there, so presumably someone here may have had some experience of it.