Listen, I like butterflies as much as the next person, but bats 100% should be our mascot instead. Here are my reasons.
Bats have similar profiles to butterflies, but bat rash saves spoons to say and alliteration makes it cuter.
Bats also represent vampires, and between our sun aversion (lupus symptoms or heat regulation), GI issues (making garlic a no-go for us), and pale or blueish hue (thanks Raynauds), we all are essentially modern day vampires. Also, nephritis just sounds like it could be vampire related term.
Bats are sky puppies that look normal and sane, but often have rabies unbeknownst to the viewer. Kinda like how we look like fully functioning humans, but our immune system ravages us on the inside.
Bats are varied with more individual features, allowing for easier visual representations of personality. Case in point at this cute sticker made by https://www.instagram.com/meinmyownheadx/ where bat is both cute and gothic. (I am unaffiliated with this artist, I simply thought it was cute)
In conclusion, bats>butterflies. I rest my case.