Features of oral psoriasis:
(1) Oral involvement is uncommon and tends to be seen with generalized pustular psoriasis or other form of severe psoriasis.
(2) Most patients with oral involvement have cutaneous manifestations of psoriasis.
(3) The patient may have geographic tongue.
(4) The patient may develop:
(4a) scaly lesions on the lips
(4b) hyperkeratotic lesions on the oral mucosa
(4c) erythematous annular plaques that bleed easily
(5) A patient with psoriatic arthritis may develop temporomandibular joint arthritis.
(6) A biopsy of a mucosal lesion will show histopathologic features of psoriasis, but these changes are often nonspecific.
Supportive findings may include:
(1) a family or personal history of psoriasis
(2) exclusion of alternative diagnoses
Diagnosis of oral psoriasis in the absence of cutaneous manifestations is best done by an expert.