Differential Diagnosis for Vaginal Itching with All Testing Negative

Single Most Likely Diagnosis

• Vulvar Lichen Simplex Chronicus: This condition is characterized by intense itching and scratching, leading to a cycle of inflammation and skin thickening. It's often associated with atopic diseases and can be triggered by various factors, including stress and irritants. The fact that all testing is negative supports this diagnosis, as it's primarily a clinical diagnosis based on history and physical examination.

Other Likely Diagnoses

• Irritant or Allergic Contact Dermatitis: This could be due to soaps, douches, condoms, or other products that come into contact with the vulvar area. Even if testing for infections is negative, an allergic reaction or irritation could still cause significant itching.
• Atrophic Vaginitis: Although more common in postmenopausal women, atrophic vaginitis can occur in any woman with decreased estrogen levels. It leads to thinning and drying of the vaginal walls, which can cause itching, burning, and discomfort.
• Vulvar Intraepithelial Neoplasia (VIN): While less common, VIN can cause persistent itching. It's a precancerous condition that requires further investigation, including biopsy.

Do Not Miss Diagnoses

• Invasive Cancer (Vulvar or Vaginal): Although rare, any persistent and unexplained vaginal itching, especially in older women or those with risk factors, warrants a thorough evaluation to rule out cancer. A delay in diagnosis can significantly impact prognosis.
• Lichen Sclerosus: This is a chronic inflammatory skin condition that can affect the vulvar area, leading to itching, pain, and architectural changes. It's associated with an increased risk of vulvar cancer, making early diagnosis crucial.
• Systemic Diseases with Vulvar Involvement: Certain systemic diseases, such as Crohn's disease or Behçet's disease, can have vulvar manifestations, including itching and ulcers.

Rare Diagnoses

• Vulvar Vestibulitis: Characterized by chronic pain and itching localized to the vestibule, this condition can be challenging to diagnose and treat.
• Erythema Multiforme: A skin condition that can affect the vulvar area, causing itching, burning, and characteristic target lesions.
• Zinc Deficiency: Although rare, zinc deficiency can cause skin lesions and itching, including in the vulvar area.
• Neurological Causes: Rarely, vaginal itching can be of neurological origin, such as neuropathic itching due to nerve damage or multiple sclerosis.