What causes large blisters on the foreskin, and what should be done about it?

In general, the appearance of large blisters on the foreskin may be caused by friction irritation, local allergy, genital herpes, balanoposthitis, or fixed drug eruption. Depending on the specific situation, improvements can be made through general care, medication, or other treatments. Detailed analysis is as follows:

1. Friction Irritation

Tight clothing or frequent sexual activity may cause repeated friction on the foreskin, leading to local skin tissue damage and exudation of tissue fluid, resulting in blister formation. Wear loose, breathable cotton underwear, temporarily avoid sexual activity, keep the area clean and dry, and avoid scratching.

2. Local Allergy

Exposure to allergens such as condoms or shower gels may trigger a skin allergic reaction, increasing vascular permeability and causing blister formation, often accompanied by itching. Immediately discontinue use of the suspected allergen, wash the area with warm water, and switch to mild, gentle cleansing products.

3. Genital Herpes

Caused by infection with herpes simplex virus type 2 (HSV-2), this is a sexually transmitted infection. Blisters typically appear in clusters, have thin walls, and easily rupture to form ulcers. Swelling of inguinal lymph nodes may also occur. Antiviral treatment should be followed as prescribed by a doctor, including topical acyclovir cream or penciclovir cream, or systemic antiviral medications such as oral acyclovir tablets or famciclovir tablets.

4. Balanoposthitis

Most commonly caused by bacterial or fungal infections, especially prevalent in individuals with phimosis. Redness and white discharge may be observed around the blisters, possibly accompanied by a burning sensation during urination. For fungal infections, antifungal medications such as clotrimazole cream or miconazole nitrate cream may be used under medical guidance. For bacterial infections, antibiotic ointments such as mupirocin ointment or erythromycin ointment may be applied.

5. Fixed Drug Eruption

A fixed drug eruption is a specific allergic skin reaction triggered when certain drugs enter the body, causing dilation and increased permeability of blood vessels in the skin and mucous membranes, leading to tissue fluid exudation and blister formation. The offending drug must be discontinued immediately. Under medical guidance, medications such as chlorpheniramine maleate tablets, ebastine tablets, or prednisone acetate tablets may be taken. Keep the affected area clean and dry.

Regardless of the cause, once any abnormality appears on the foreskin, even if initial observation is chosen, changes should be closely monitored. Immediate medical attention is required if symptoms worsen or discomfort persists. Additionally, maintain good personal hygiene and avoid unsafe sexual practices.