Brightbleed

There's something distinctly horrifying about watching your friends go down screaming because you tried to heal them. If only they'd learn to tell me what idiotic pills they'd taken! I'm sick of wasting resurrection spells on them!

Regularly known as 'the healer's nightmare', brightbleed is the name given to a condition brought about by the nasty combination of magic-blocking medication and positive energy. Priests and doctors hand out the former type of medication for issues that affect one's magical flow: for instance, a sorcerer whose bloodline began to manifest in harmful ways might take a magic-blocking medicine to suppress the volatile magic for a time whilst a more permanent fix is studied. There are also a number of recreational drugs - fizzbreath as an example - that have similar side-effects, whether stated or not.
Positive energy, meanwhile, is drawn directly from the Positive Energy Plane and is what all healing spells channel. Paladins utilise it to smite undead creatures, whereas most clerics prefer to use it to repair wounds on the battlefield. Usually, unless a creature is undead, positive energy mends damage and restores health.
When positive energy is used on somebody who's taken brightbleed, however... things change. The corpse left behind is the most damning evidence of what has occurred. White liquid, still glowing with inner light, pours out of the body's pores and holes, burning its way out and sealing the burns in place. Thankfully, the disorder is not terminal with correct treatment.
A negative energy alternative nicknamed blightbleed is possible in theory if the patient heals from negative energy, but most of these patients are undead and thus not as susceptible to magic-blockers in the first place.

Causes

Mixing beer and liquor is NOTHING compared to mixing anti-magics and, well, magics? Honestly, I don't know what you expected!

— Canthe Pa'lustris, on healing someone with brightbleed

As discussed, brightbleed can usually only be contracted through the interaction of magic-blocking medicine and positive energy. Studies run by Celesthem Temple and various other hotspots of divine research have determined that the critical interaction occurs when the aforementioned medicine has made its way into the bloodstream, with brightbleed being a possible outcome only if the medicine is still properly active.
To safely avoid the disease, waiting for 1 - 3 days after the medicine was taken is best practice for healers.

Symptoms

...We're going to need a better cleanup crew for this, ain't we.

— Anonymous apprentice wizard, upon encountering expired brightbleed victim

The first sign that someone has been afflicted with brightbleed is the very obvious pained reaction to positive energy. Instead of the usual light tingling, the energy burns them as it runs rampant through their blood: in addition to the classic screaming and complaints of a burning pain, they may begin to convulse uncontrollably.
If not caught immediately, brightbleed quickly progresses to the point of burning its way out of the body through any available orifice. The energy has an odd effect on blood, turning it a glowing white - thus meaning the classical corpse with liquid pouring from it is, in fact, bleeding profusely from every possible exit.

Treatment

Treating brightbleed is only possible if the reaction is quick, or if the patient can be somehow frozen in place (perhaps by magical means such as Time Stop or Icy Prison). Negative energy must be applied to counter the energy in the patient's veins, and must swiftly be followed by a rapid-acting dose of any substance capable of reversing a magic-blocker. The patient may still require heavy healing afterwards, but this should be done carefully to avoid repeating the illness.
Alternatively, an anti-magic field or another method of nullifying the effects of positive energy can be applied to assist. Even something as twisted as reversing the patient's ability to heal from positive energy can be beneficial, though this does put them at risk of blightbleed or simple death from positive energy effects.

Prognosis

What happened to my face..? Can, can you fix it?! I can't look like this! It's a, I'm a mess!

— distraught patient, two days before death

Considering the expertise and time-frames involved in surviving brightbleed, most who contract it will shortly die. Those lucky to survive will need intense care to be sure they do survive, and will endure a sensitivity to both positive energy for months after. If they managed to recover after reaching the point where the liquid burnt its way out of their bodies, their bodies will likely bear a number of burn marks as a result of the illness.
The psychological effects linger longer than anything the illness does, given access to proper healing: the afflicted may never again feel comfortable in medical environments or temples, and may react sharply to anything resembling the white liquid they once emitted.

Prevention

Avoiding the combination of specific medicine and positive energy is enough to entirely avoid brightbleed. That being said, certain adventurers have taken to using syringe spears to inject magic-blockers into their foes to then deliberately induce brightbleed.

They deserved it! Probably.

Type

Magical

Origin

Magical

Cycle

Short-term

Rarity

Uncommon