Hi Adrian!

I think your Luo Han has the same kind of "pox", mostly, your water para is not good, or dirty, you'll have to change the water every 2 or 3 days, and add 0.3% of salt to the water(can kill most of the bad bugs). 0.3% of salt only can be use for 2 weeks(recommended) for each treatment. only 0.1% of salt can only be use throughout the year. High salt level might lower down the fish's immune system.

Hope to hear from you soon, let ushow is your Luo Han doing now!

Regards,
John