Look at the surface of the leaves. If your plant is indeed infested with spider mites, the leaves may have yellow blotches on them. When light falls on the leaves, you may see a silvered look or even streaks of bronze or silver.
Healthgrades Editorial Staff. White patches in the mouth are a common symptom of infection, inflammation, trauma, malignancy, and other underlying conditions and diseases. Mouth white patches result from pathogens, such as bacteria, viruses and fungi, which inflame the lining of the mouth causing swelling, redness, and ulcer formation.
Introduction & background. Canker sores, also known as Apthous ulcers, are painful little ulcers with a red border that can form anywhere inside the mouth. These are shallow lesions that can appear singly or in small groups and are formed because of soft tissue injury or stress. They are usually white or yellow in color and are often very tender.