It could be a host of different things, and even possibly just blisters from working, but that is just a guess, who knows what it is? We are not Doctors, and we can not and would not even try to tell you what it is! Not even from a picture! But if your concerned about it, which apparently you are, since you came here and even had a picture! Then I would strongly suggest, either going to your doctor or if your medical facility has a covenient care clinic go to that, and have it looked at and checked out!
Good Luck to You
Moderator Chronic Pain
I'm Retired USAF, went back to school and became an RN, and now am on full disalbility!--Degenerative Disc (affecting mostly the thorasic disc but all levels involved), C6/7 laminectomy/diskectomy& fusion, Osteoarthritis, Ulcerative colitis, Chronic Pain, Fibromyalgia, Complex Sleep Apnea, and host of other things to spice up my life!(NOT!) Medications: Oxycontin, Percocet, Baclofen, Sulfasalazine, Metoprolol, Folic Acid, Supplemental O2 at 3lpm with VPAP Adapt SV