Differential Diagnosis for Blister on Vagina
Single Most Likely Diagnosis
- Genital Herpes: This is the most common cause of vaginal blisters, typically presenting with painful, fluid-filled blisters that rupture to form ulcers. The diagnosis is often made clinically, but can be confirmed with viral culture or PCR.
Other Likely Diagnoses
- Syphilis: The primary stage of syphilis can cause a painless chancre, which may appear as a blister or ulcer on the vagina. Diagnosis is made with darkfield microscopy or serologic testing.
- Contact Dermatitis: Irritant or allergic contact dermatitis can cause blisters on the vagina, often due to exposure to soaps, douches, or other products. Diagnosis is clinical, with resolution of symptoms after removal of the offending agent.
- Vulvar Vestibulitis: This condition causes chronic pain and inflammation of the vulvar vestibule, which may lead to blister formation. Diagnosis is clinical, with tenderness to touch and pain with intercourse.
Do Not Miss Diagnoses
- Squamous Cell Carcinoma: Although rare, vulvar cancer can present with a blister or ulcer on the vagina. Biopsy is necessary for diagnosis, and prompt treatment is essential to prevent progression.
- Lichen Sclerosus: This condition can cause thinning and blistering of the vulvar skin, and is associated with an increased risk of vulvar cancer. Diagnosis is clinical, with biopsy to confirm.
- Immunobullous Disorders: Conditions such as pemphigus and pemphigoid can cause blisters on the vagina, and may be life-threatening if not treated promptly. Diagnosis is made with biopsy and immunofluorescence.
Rare Diagnoses
- Vulvar Aphthae: These are rare, painful ulcers that can appear on the vagina, often without a clear cause. Diagnosis is clinical, with resolution of symptoms after treatment with topical corticosteroids.
- Behçet's Disease: This rare condition can cause recurrent oral and genital ulcers, including blisters on the vagina. Diagnosis is clinical, with criteria including recurrent oral ulcers and at least two other systemic symptoms.
- Zinc Deficiency: Severe zinc deficiency can cause skin lesions, including blisters on the vagina. Diagnosis is made with serum zinc levels, and treatment with zinc supplementation can lead to resolution of symptoms.