The original description of Behçet’s syndrome included recurring genital and oral ulcerations and relapsing uveitis. This disease is also associated with cutaneous hypersensitivity; 60%–70% of patients will develop a sterile pustule with an erythematous margin within 48 hours of an aseptic needle prick.
It is more common in Japan, Korea, and the Eastern Mediterranean area, and affects primarily young adults. The cause is unknown. Two-thirds of patients will develop ocular involvement that may progress to blindness. Patients may develop arthritis, vasculitis, intestinal manifestations, or neurologic manifestations.
Of course, there are many other reasons you might have developed a reaction at the site of a blood draw. Consult your physician. But the diagnosis of Behçet’s is often missed and it's worth considering. Read the below free reference from Arthritis Research UK for much more complete information.
Free E-Booklet on Behçet’s Syndrome from Arthritis Research UK: Download Here
Fauci AS, Braunwald E, Kasper DL, et al (eds): Harrison’s Principles of Internal Medicine, ed 17.
McGraw-Hill, 2008, p 2132. 2) Klippel JH, Stone JH, Crofford LJ, et al (eds): Primer on the Rheumatic Diseases, ed 13. Springer, 2008, pp 435-439.i