White sponge nevus (WSN) is an extremely rare autosomal dominant[4] condition of the oral mucosa (the mucous membrane lining of the mouth).

WSN presents most commonly in the mouth, as thickened, bilateral, symmetrical white plaques with a spongy, corrugated or velvety texture.

The extreme rarity of the condition (estimated at 1 in 200,000 people) means that clinical evaluation of treatment options is based on very small sample sizes, often a single patient.

Some affected individuals rarely or never experience problematic symptoms, while others report sporadic/idiopathic thickening and spreading of the white plaques within their oral cavity.

Across the primary literature there is clinical evidence to support topical or systemic antibiotic or antifungal treatment in cases where symptoms have flared-up.