I am new to the forum, and thought it would be the best place to pose a few queries with regards my degenerating bathroom!
For a little while now, I have noticed black specks of mould appear around the top corners of my bathroom. The one I am mostly concerned about is the corner which consists of 2 'external' walls. I have taken photos to show what has occured...


Can anyone advise as to what my problem may be, and how to rectify it?
Here's a some more info to bear in mind:
The bathroom is very small in size, and is used daily for showers (over bath).
The wooden-panel ceiling is 'supsended', hanging maybe a foot below the original ceiling height.
The textured paint (as seen peeling away from the walls) - is this generally accepted for use in bathrooms? Also, I think the paint may well be general emulsion rather than anti-fungicidal paint.
There is no extractor fan fitted. There is a window fitted which we gerally leave ajar (maybe an inch at most).
I moved into the house 6 years ago, and I havent touched this room in terms of decorating etc.
Thanks for any advice guys.