Will Tightening Arm Skin Leave Severe Scars?

Thank you for your question. you may be a good candidate for arm lifting surgery.  This  procedure will  improve the shape of the arms;  the scar will be located under the armpit but after the surgery I advice my patients to use scar removing gel for min 3 months to see the scar improvement. 
I advice you to visit an experienced board-certified plastic surgeon for consultation

With any
surgical procedure, you’re bound to have some scarring. However, the severity
and longevity of scars is affected by factors such as your age, general health,
and if you use a scar-lightening treatments to aid in fading your scar. Most
patients notice that their scars are significantly flatter and lighter nine to
twelve months after surgery. It’s
important to remember that because of the location of the incision, scars from
brachioplasty seldom heal fully. However, incisions are usually made on the
underside of the arm and usually can be hidden by wearing a short-sleeved shirt
of loose sleeves. After the incision has healed, you may want to speak with
your surgeon about using a scar lightening cream containing salicylic acid,
glycolic acid, hydroquinone, or onion bulb extract, all of which have been
linked to improving scarring and other forms of hyperpigmentation.

Kat,Hi, congrats on the weight loss of 100lbs! If you think of it as butter, that is 400 sticks of butter that you lost off your body! Unfortunately, the skin still remains. Every surgery creates a scar. And each person’s individual body heals differently to create different types of scars. If you make big thick scars, then chances are you will on your arms. The degree of depends on the tension or pulling of the scar. Based on your photos, you have very loose skin that can be tightened and should not cause significant tension or pulling.If you have the surgery and start to notice that the scars are getting big, then you and your surgeon can always utilize silicone gel, scar massage, and/or steroid injections. I hope that helps. Best of luck!