What causes blisters behind the glans penis?

Possible causes of blisters appearing behind the glans: 1. Mechanical irritation: Wearing low-quality synthetic fiber underwear frequently or excessive masturbation may cause repeated friction and irritation to the local skin behind the glans, leading to blister formation. 2. Genital herpes: This is caused by infection of the skin behind the glans with the herpes simplex virus. After entering the body, the virus replicates within skin cells, causing local inflammation. Under inflammatory stimulation, blisters may form behind the glans, which can progress to erosion or ulcers, often accompanied by itching, burning sensation, and pain. 3. Balanitis eczema: If a patient frequently wears tight-fitting underwear, resulting in poor ventilation of the glans area, or has abnormal immune function, balanitis eczema may be triggered. This condition may lead to papules behind the glans, which can gradually develop into blisters.