Author: Sam Killian, M.D. Educational Pearls Phimosis refers to the inability to retract the distal foreskin over the glans penis in uncircumcised males. Paraphimosis is the entrapment of the foreskin proximal to the glans penis in these patients. Phimosis is rarely a medical emergency, but requires follow up with urology. Paraphimosis, on the other hand, can cause venous and lymphatic insufficiency, leading to infarction, necrosis and autoamputation. Therefore, paraphimosis requires emergent treatment with manual reduction of the foreskin or surgery. References: Aaron Vunda, M.D., Laurence E. Lacroix, M.D., Franck Schneider, Sergio Manzano, M.D., and Alain Gervaix, M.D. Reduction of Paraphimosis in Boys. N Engl J Med 2013; 368:e16