So I'm new to 4e, and I was unable to find the rules for creation of diseases. I want to create a low-level disease that kobolds can throw in you among other dirty tricks with some Lovecraft vibes.

I use a few cosmetic homerules here :

1. Endurance check is made at the end of disease cycle, rather then every long rest.
2. You don't know what the disease is, unless your are able to identify it, which may be harder or easier on a different stage.
3. Once you identify disease you can make an additional check about special treatment, that can help you to cure disease if special conditions are met.

I planned it as a slow disease, that gradually grows from sweet to nightmarish and gives players time to discover what the hell is going on. I still unsure about numbers and ask you to help with them.

Here what I have so far: