Oral medicine: 6. white lesions

Specialist referral may be indicated if the Practitioner feels:

Truly white oral lesions appear white usually because they are keratotic (composed of thickened keratin, which looks white when wet) or may consist of collections of debris (materia alba), or necrotic epithelium (such as after a burn), or fungi (such as candidosis). These can typically be wiped off the mucosa with a gauze swab.

Other lesions, which cannot be wiped off, also appear white usually because they are composed of thickened keratin (Figure 1). A few rare conditions that are congenital, such as white sponge naevus (Figure 2), present in this way, but most white lesions are acquired and many were formerly known as ‘leukoplakia’, a term causing misunderstanding and confusion. The World Health Organization originally defined leukoplakia as a ‘white patch or plaque that cannot be characterized clinically or pathologically as any other disease’, therefore specifically excluding defined clinicopathologic entities such as candidosis, lichen planus (LP) and white sponge naevus, but still incorporating white lesions caused by friction or other trauma, and offering no comment on the presence of dysplasia. A subsequent international seminar defined leukoplakia more precisely as: