One possibility. I had something resembling a cyst or wart (about the size of a pea) appear on the outside of my right index finger, near the joint below the nail. It did not hurt but was rather unsightly. I saw an orthopedic doctor who removed it . . . and to his great surprise it was caused by a thorn. To my surprise it was not removed in his office but in a surgical room. Perhaps that is common procedure.