What are the other Names for this Condition? (Also known as/Synonyms)

• Cannon's Disease
• Hereditary Leukokeratosis of Mucosa
• White Folded Gingivostomatitis

What is White Sponge Nevus? (Definition/Background Information)

• White Sponge Nevus is an inherited genetic condition of the mouth that is characterized by thick white lesions on the mucosal surface of the cheeks (inside the mouth). The condition is also known as Hereditary Leukokeratosis of Mucosa
• There are no severe signs and symptoms associated with White Sponge Nevus. However, the condition may involve the entire mouth, and rarely affect other mucosal surfaces too, such as the esophagus, genitalia, or rectal and anal region. Even though the prognosis is excellent, there is no effective treatment for White Sponge Nevus

Who gets White Sponge Nevus? (Age and Sex Distribution)

• White Sponge Nevus is a congenital occurrence that may be seen at birth. However, most cases are diagnosed in young children and adolescents
• Both males and females are affected, although some reports indicate a preference for females
• Worldwide, there is no racial or ethnic preference observed. However, this condition is rare

What are the Risk Factors for White Sponge Nevus? (Predisposing Factors)

• A family history of the condition is a major risk factor for White Sponge Nevus
• No other predisposing factors are presently unidentified

It is important to note that having a risk factor does not mean that one will get the condition. A risk factor increases one’s chances of getting a condition compared to an individual without the risk factors. Some risk factors are more important than others.

Also, not having a risk factor does not mean that an individual will not get the condition. It is always important to discuss the effect of risk factors with your healthcare provider.

What are the Causes of White Sponge Nevus? (Etiology)

• White Sponge Nevus is a genetic condition that is inherited in an autosomal dominant manner. It is caused by mutations on the keratin 4 or keratin 13 (KRT4 or KRT13) genes
• However, not all cases of White Sponge Nevus are inherited. Some are known to develop the condition sporadically, in the absence of any positive family history of the condition

Autosomal dominant mode of inheritance: Autosomal dominant conditions are traits or disorders that are present when only one copy of the mutation is inherited on a non-sex chromosome. In these types of conditions, the individual has one normal copy and one mutant copy of the gene. The abnormal gene dominates, masking the effects of the correctly function gene. If an individual has an autosomal dominant condition, the chance of passing the abnormal gene on to their offspring is 50%. Children, who do not inherit the abnormal gene, will not develop the condition, or pass it on to their offspring.

What are the Signs and Symptoms of White Sponge Nevus?

The presence of White Sponge Nevus can be described as mild or severe. It can vary from one individual to another. The signs and symptoms may include:

• Presence of soft white mucosal lesions on the inside of the cheeks
• In most cases, the lesions are bilateral, involving both cheeks, and sometimes symmetrical in appearance
• The surface of the white patch feels corrugated and spongy; in some, the entire mouth may be covered
• There is no pain or discomfort noted, but affected individuals can sense the lesion with their tongue
• Eating or speaking difficulties are not generally reported

The outside of the mouth, skin, hair, or nails are not involved. However, rarely, the mucosal surfaces at other sites, such as the nasal tract, food-pipe, rectum and anus, or the vulva/vagina, may show an involvement following White Sponge Nevus affecting the oral mucosa.

How is White Sponge Nevus Diagnosed?

A diagnosis of White Sponge Nevus may involve the following exams and procedures:

• Physical examination of the individual and medical history evaluation, including family history and absence of other skin conditions
• Oral cavity examination
• Skin biopsy: A skin tissue biopsy is performed and sent to a laboratory for a pathological examination. The pathologist examines the biopsy under a microscope. After putting together clinical findings, special studies on tissues (if needed) and with microscope findings, the pathologist arrives at a definitive diagnosis
• Molecular genetic testing, if available

A differential diagnosis is important to exclude other conditions presenting similar signs and symptoms may be needed. These include:

• Cheek biting 
• Cutaneous lupus erythematosus
• Darier disease
• Dyskeratosis congenita
• Hereditary benign intraepithelial dyskeratosis
• Leukoplakia
• Oral lichen planus
• Oral submucous fibrosis
• Oral thrush
• Pachyonychia congenita
• Syphilis

Many clinical conditions may have similar signs and symptoms. Your healthcare provider may perform additional tests to rule out other clinical conditions to arrive at a definitive diagnosis.

What are the possible Complications of White Sponge Nevus?

The possible complications due to White Sponge Nevus include:

• Emotional stress due to concerns of malignancy
• Cosmetic concerns
• Superimposed bacterial and fungal skin infections
• Treatment complications

How is White Sponge Nevus Treated?

The healthcare provider may not recommend any treatment for mild cases of White Sponge Nevus. In such cases, reassurance and a ‘wait and watch’ approach may be followed.

When treatment is necessary, the following measures may be considered:

• Use of topical antibiotic mouthwash
• Oral antibiotics such as doxycycline, amoxycillin, or erythromycin
• Administration of medications, including retinoid therapy, although these are not known to be effective
• Antifungal therapy for secondary infections, if necessary

Regular follow up visits with the healthcare provider is important and recommended.

How can White Sponge Nevus be Prevented?

White Sponge Nevus may not be preventable since it is a genetic disorder.

• Genetic testing of the expecting parents (and related family members) and prenatal diagnosis (molecular testing of the fetus during pregnancy) may help in understanding the risks better during pregnancy
• If there is a family history of the condition, then genetic counseling will help assess risks, before planning for a child
• Active research is currently being performed to explore the possibilities for treatment and prevention of inherited and acquired genetic disorders

What is the Prognosis of White Sponge Nevus? (Outcomes/Resolutions)

The prognosis of White Sponge Nevus is generally excellent with appropriate treatment of the condition.

• The administration of topical and systemic antibiotics does not cure White Sponge Nevus but is known to mitigate the signs and symptoms, even though it is not a bacterial infection
• When the medications/treatment is stopped, the condition is known to recur

Additional and Relevant Useful Information for White Sponge Nevus:

The following DoveMed website link is a useful resource for additional information:

https://www.dovemed.com/healthy-living/dental-health/