Clinical meaning
Balanitis is inflammation of the glans penis, while balanoposthitis involves inflammation of both the glans and the prepuce (foreskin). The condition results from disruption of the normal preputial microenvironment. In uncircumcised males, the subpreputial space is warm, moist, and relatively anaerobic, creating conditions favorable for microbial overgrowth when hygiene is inadequate or the local immune environment is compromised. Candidal balanitis (the most common infectious etiology) occurs when Candida albicans, a commensal organism, overgrows in the setting of local moisture, hyperglycemia (providing glucose as a substrate for yeast proliferation), antibiotic use (eliminating competing bacterial flora), or immunosuppression. The yeast adheres to the epithelium via adhesins, produces phospholipases and proteinases that damage the mucosal barrier, and triggers an inflammatory response with erythema, edema, and satellite papulopustules. Bacterial balanitis may involve Group A Streptococcus, Staphylococcus aureus, or anaerobic organisms, presenting with purulent discharge, erythema, and sometimes cellulitis. Irritant or contact balanitis results from chemical irritation (soaps, spermicides, latex) causing a non-infectious inflammatory dermatitis. Zoon balanitis (plasma cell balanitis) is a chronic benign condition of unknown etiology seen in middle-aged to elderly uncircumcised men, characterized by well-demarcated, glistening, cayenne-pepper-spotted erythematous plaques with a dense plasma cell infiltrate on biopsy. Lichen sclerosus (balanitis xerotica obliterans, BXO) is an important differential that causes white, atrophic, sclerotic changes of the glans and prepuce, with risk of urethral meatal stenosis and a small but real risk of squamous cell carcinoma (4-8% lifetime).