Balanitis: Inflammation of the head of the PENIS, glans penis.Balanitis Xerotica Obliterans: An atrophic and sclerotic condition of the head of the PENIS, glans penis. Sometimes it leads to stenosis and occasionally obliteration of the external meatal orifice.Penile Diseases: Pathological processes involving the PENIS or its component tissues.Phimosis: A condition in which the FORESKIN cannot be retracted to reveal the GLANS PENIS. It is due to tightness or narrowing of the foreskin opening.Lichen Sclerosus et Atrophicus: A chronic inflammatory mucocutaneous disease usually affecting the female genitalia (VULVAR LICHEN SCLEROSUS) and BALANITIS XEROTICA OBLITERANS in males. It is also called white spot disease and Csillag's disease.Circumcision, Male: Excision of the prepuce of the penis (FORESKIN) or part of it.Penis: The external reproductive organ of males. It is composed of a mass of erectile tissue enclosed in three cylindrical fibrous compartments. Two of the three compartments, the corpus cavernosa, are placed side-by-side along the upper part of the organ. The third compartment below, the corpus spongiosum, houses the urethra.Protozoan Infections: Infections with unicellular organisms formerly members of the subkingdom Protozoa.