Runaway Regeneration Syndrome

Day three of treatment - Subject's wounds have healed with exceptional rapidity. Overall, her healing rate is well within the 99th percentile of those treated with full bacta exposure. We expect full recovery within two galactic standard weeks.
Day seven of treatment - The reattached limbs have successfully grafted back to her frame and show little scarring and no potential for rejection or necrosis. Anticipate beginning physical therapy within the next two days.
Day eight of treatment - Overnight a slight dermal cyst appeared on her cheek below the right mandible. Biopsy of the affected skin indicated heightened bacta response markers. Ceasing bacta exposure treatment.
Day nine of treatment - Subject's affected skin has started to suppurate bacta response medium. Scar tissue has spread from the right malar bone to the neck just above the clavicle and across both mandibles.
Day nine addenda - Dermal anomaly continues to fester and spread. Performed emergency excision to the surrounding tissue to stop Runaway Regeneration Syndrome (RRS). Subject's bacta tank has been drained into medical waste and undergone Class II decontamination.

Medical journal of physician on Torn Station

Transmission & Vectors

About 1 in 4,000 cases of bacta treatment result in RRS, with odds of reaction and severity increasing with combat kits and synthetic bacta compounds. Whether factory-grown xoorzi fungus' distinct alazhi cultures or kavam harvested from off-world sources causes this problem is still undetermined.
Alazhi is cultured from xoorzi, a fungus native to Thyferra and a natural symbiont to the indigenous Vratix and Knytix. As a mass-produced product, xoorzi is grown in factories in a large-scale greenhouse and cultured by the ton. More than 95% of the bacta used across the galaxy uses fac-grown xoorzi, but has not been conclusively linked to RRS frequency.
Kavam is a resin compound secreted by the Vratix and Knytix and undergoes a mutagenic transformation when combined the properly prepared alazhi cultures. Studies into the difference between the kavam of Vratix, wild Knytix, or farmed Knytix have so far been inconclusive due to spotty control of kavam sourcing methods.
Ambori solutions of various origins and production methods seem to have little or no correlation to vector. That said, the principle differences between field-pac bacta and full-exposure bacta tanks lies in the quantity and mixture of ambori and the delivery method. It is therefore suspected that RRS is linked to the concentration and localization of bacta treatments, as field-pacs are usually applied with 800-1000% of the concentration of a typical tank treatment.
The severity of treatment period has also been linked with odds of contracting RRS, though this link has not been conclusively proven.

Causes

RRS is caused by a mutation when a subject comes into contact with the bacterial agents critical to the bacta reaction. Damaged cells undergo a tumorous growing process, building out from the damaged areas. The stem cells created as part of the regeneration process are affected in such a way that the afflicted cells do not recognize them, attacking and suppurating the area with rapidity exceptional even for bacta responses. Scar tissue builds up over the area; in extreme cases, the growth rate can be observed without medical apparatus.

Symptoms

Subjects typically show enhanced recovery as an initial symptom of RRS. More than 90% of all confirmed cases of RRS are presaged by a period of 99th percentile growth lasting for 2-3 days before other symptoms manifest themselves.
Skin suppuration is a universal symptom amongst confirmed cases of RRS, though it is supposed that more subtle symptoms of RRS are simply ignored by subjects. Skin suppuration at the start of RRS will be maturated pus vessels, sensitive to touch and easily breached to weep a bacta-rich pus. After RRS progresses into large structures or goes dormant, however, the skin suppuration calcifies into uncomfortable, tough skin growths that are resistant to superficial damage and surgical intervention. RRS skin growths, even in dormant cases, will grow back after surgery.

Treatment

To date, excision of healthy tissue around the perimeter of RRS growths is the only viable method of treating active cases of RRS. Giving a clearance of 2-6mm, a skilled physician can create a 'burn through' area in which non RRS healing can trap the RRS effect. The RRS suppurations fill the cordoned-off area, reinforcing tissue walls to create a tough, resilient skin layer 4-7 times thicker than normal dermis.
Dormant RRS cases are typically treated as a chronic skin condition. Moisturizers and topical analgesics can ease most of the discomfort of affected regions, though RRS over already-sensitive body parts can result in synesthesia, phantom pain, and hypersensitivity. Brain-wiring has been put forward for particularly bad cases, resulting in deadening of nerves in the effected area.

Prognosis

RRS that is diagnosed and receives intervention within the first two days can generally be contained with high success rate. Contained RRS structures result in lifelong chronic skin lesions that require usually-minor treatments for the rest of the subject's life.
RRS that is particularly advanced or only diagnosed within 3-5 days of first mutation will need to be treated with bionic replacement. Such replacement procedures are typically the most common deciding factor for physicians to recommend artificial prosthesis.
RRS that is especially insidious or goes untreated for the 6 or more days will present high chance of fatality. Typical RRS flare-ups by this stage will cover 40-70% of the patient's body and will impair function of multiple limbs and at least one major organ.

Epidemiology

As a mutation specific to the subject, RRS is not contagious between individuals. Studies suggest that the supply of bacta used by a subject with RRS can be contaminated. While the contaminated-bacta vector has not been conclusively illustrated, it is common practice for physicians to dispose of the remaining bacta and disinfect the tank in question.

History

Bacta has been used for several thousand years, replacing the much less effective and more temperamental Kolto compounds of previous years. The first cases of RRS began to be documented within the first couple of centuries. Due to how widespread its use was by the time these first cases were reported, any chance to contain the bacta industry until RRS was properly isolated and understood was lost.

Cultural Reception

Due to the distinctive lesions that resemble burn scars, RRS is most commonly referred to as "Bacta Burn". It will usually exhibit as reddish-orange tissue that is resilient and rough to the touch. It's most often identified as a common scar amongst mercenaries, bounty hunters, and those in other high-risk occupations. There is little stigma to the lesions themselves, but most people associate sufferers of RRS with those high-risk--and sometimes illegal--professions.

Type

Bacterial

Origin

Mutated

Cycle

Chronic, Acquired

Rarity

Rare

Game Mechanics

Vector: CF while being treated with bacta.
Resistance roll: Roll HT with a cumulative -4 for field-pac, -2 each for non-standard alazhi, kavam, or concentration. Infected on a failure.
Delay: 24 hours
Damage: 1 point of toxic damage per day since afflicted (2 pts on the second day, etc).
Cycles: 10 cycles (up to 52 pts of damage)
Symptoms: Chronic pain, sensitivity, mild sensory problems, toughened skin.
Treatment: Surgery with a difficulty equal to the number of days since afflicted (-2 on day 2, -3 on day 3, etc).
Ongoing effects Resistant (+4) to subsequent RRS infections DR 1 (tough skin) over the afflicted area Chronic Pain (mild; constant; mitigated by minor daily medical intervention) Insomniac (mild) probably Distinctive Features (Bacta Burn scarring)