Kazko is right on. my two cents...
Gliders' mouths, and of course their nails, are a veritable writhing petri dish of bacteria. Gliders are well known for a bacteria flora soup in their gut and mouths. They can maintain a pretty high bacteria count without being "sick."
Earlier this year a glider bite landed me in the hospital, with surgery to my hand and index finger. They had to cut open by palm to force a catheter into my finger to flush out all the bad liquid. They kept that in for days. I was on broad spectrum antibiotics for over a month, and for over a week intravenously.
Just as an example, the microbes found included were Streptococcus Anginosus and Abiotrophia (formerly called nutritionally variant strep). Abiotrophia is often obscured by the Streptococcus Anginosus as Abiotrophia is apparently a "satellite" bacteria that rides along with Streptococcus Anginosus but takes a few more days to incubate and show up on the petri dish. It took from friday the 27th of February (leap year) til March 4th (5 days) for them to confirm it in the lab. The Streptococcus Anginosus showed up in two days.
I mention this because we are susceptible to bites where an infection can find its way into the tendon sheath of finger and wrist. The tendon sheath is highly susceptible to infection. Why? Because it is sugary, dark, warm, and has hardly any blood to wash away and attack infection.
Now consider the length of a glider's teeth. It is EASY for them to puncture your skin and drive a load of bacteria into the tendon sheath. Once there, it is EASY, being sugary, dark, wet, warm and bloodless, for bacteria to multiply. Once the tendon sheath is infected, the infection travels up and down the tendon, as if pulled by capillary action through a straw. In extreme cases, this can result in the need for amputation.
My infectious disease specialist who cared for me post surgery said you should wash thoroughly with an antibacterial soap after handling gliders and also use hydrogen peroxide on scratches and cuts - even teeny ones.
In addition to garden variety bacterium, gliders can also transfer more heinous wee beasties. For example, salmonella, giardia and leptospirosis. All are zoonotic, meaning humans can catch those from gliders.
I agree that babykiki's arm photo is very likely not the result of being allergic per se, but just the human body's reaction to having a host of bacteria scraped into the flesh from sharp nails. Our bodies send white blood cells to affected areas to battle the bacteria. Slight swelling and redness are a byproduct of this process. Look, I'm no doctor, but my arms look like that all the time, and I'm not "allergic." And so does my stomach considering I hold gliders against it while cutting their nails. I cut well over a thousand glider nails a month, so I'm pretty cut up looking even when wearing two t-shirts for protection. My arms are also scarred from gliders "grooming" the scabs of cuts received by,... gliders.
Incidentally, a local vet, Dr. Jay Holt of Animal Kindness Veterinary, is allergic to male gliders. This is ironic owing to the fact that he and his DVM wife, Valerie, are marsupial experts and have kangaroos on their farm... But he's not allergic to female gliders...