If you water too much it could be excess water coming out of the leaves.My flowers at the base of each ozz sap. Take a cotton tip with a little mouth wash and try to remove it and repond and let us know what happened. They don't get diseases or bugs, It is something you are doing wrong with your care. Now don't take this personally, is this a new species for you? I get black spots, or dried up spots, it because I don't water on a regular schedule. Put a little bone meal in your mix. Repot in the Spring whent it warms up. I use a mouth wash that doesn't have alcohol in it (Colgate) Soap and water is just as good. Saffer's soap is great. You might want to water the plant with warm water, every Sat. morning in the summer and in the winter once a month if its warm enoungh in the early morning about 5:00 no lower 55F It also may need repotting, don't let it get in a draft. and be sure to tell the plant how much you love it.

Thank you so much, norma_2006. The san is my new baby. I have just got it for about 3 weeks. When I got it, it has those brown spots already. So I just want to know what has happened on my baby. Thank you for your sharing. I really learn a lot:)

Poor cultural care before you got it. This species noramlly don't get a disease, they could have been bit in order to get water by an insect. Check with who you purchased it. You may get lucky, mine seem to get worse than that. I am going to start using bone meal. The one outside under a high grade hard plastic double ply roof doesn't seem to have the problems that the inside plants have. They have more air circulation going for them.

Hold off on the bone meal for inside use. It will draw those tiny flies. And all sorts of soil insects. Unless you can compost it or let it fully decompose. Mine was so raw that my dog wanted to eat it. I was planning to use a over the counter potassium pill for people. One pill/gallon water for one watering only to see what will happen.
Stush

those little brown spots are like permanent scabs, probably as the result of mechanical damage. They will not get worse and they will not go away. During the course of their handling, leaves can get poked by other leaves, and some have very pointy leaves. I would not worry about these one bit.

I just wanted to say that if a sansevieria is over-watered, that excess water does not "come out of the leaves" and leave behind little brown spots.
April, I see you live in Hong Kong. You should be able to find many different Sansevieria species and hybrids there - some not commonly seen in North America.. Send pictures of any that you find and like!

I have these brown bumpy spots on mine too that look like sesame seeds. I can't scrape them off like scale. Any thoughts on what these are? They are on 4 out of 20 stalks and new.... My watering has always been spot on...