Lichen sclerosus and balanitis on a 64-year-old man's penis, affecting the glans (centre) and prepuce (foreskin). Lichen sclerosus is an inflammatory condition affecting the skin, caused by an immune response of unknown origin. It leads to loss of skin pigment, atrophy (thinning), and loss of elasticity of the affected skin. Balanitis is inflammation of the glans of the penis. This patient's condition followed a previous circumcision, and more recent brachytherapy (a form of radiation therapy) for prostate cancer.