The aim of this intervention study is to compare the effect of topical Rebamipide (regular and nanoparticulated) to topical Clobetasol propionate in management of Methotrexate induced oral mucositis in patients with rheumatoid arthritis.

A random sample of patients diagnosed with rheumatoid arthritis attending at the Rheumatology clinic in faculty of Medicine, Cairo University Hospital, will be enrolled by the investigator in the study in a consecutive order after being examined for methotrexate induced oral ulceration by means of history and clinical examination.

Since oral mucositis associated with Methotrexate include production of free radicals, increase of inflammatory cytokines, and alteration of intracellular signal transduction, this suggests that Rebamipide should be useful for its treatment and prevention. Thus, this RCT will be the first to evaluate the treatment of Methotrexate-induced oral mucositis using Rebamipide and Rebamipide nanoparticles in patients with rheumatoid arthritis.

Inclusion Criteria:

• Patient who agreed to sign the informed consent.
• Age: 20-70 years old.
• Gender: males and females
• RA patients treated with MTX and suffering from MTX-induced oral ulceration.

Exclusion Criteria:

• Patients refused to sign the informed consent.
• Pregnant or lactating females in their child bearing age group.
• patients with known or suspected history of hypersensitivity to any of the ingredients of the preparation of the drugs used.
• Systemic disease: such as uncontrolled diabetes mellitus, auto-immune diseases known to cause oral ulceration, renal or liver dysfunction or any other condition considered risky by the clinician.
• Patients treated with any medication for the condition at the time of setting.
• Salivary gland diseases.
• Malignancy.