[Durgical](https://durgical.com/en/) › [DurgiPedia](https://durgical.com/en/durgipedia/) › [Dentistry](https://durgical.com/en/dentistry/) › [Oral mucosal lesions](https://durgical.com/en/dentistry/areas/oral-lesions/) › White and red patches in the mouth: approach # White and red patches in the mouth: approach - Approach to a complaint Some white patches rub off (thrush), most do not. Lasting white or red patches without a cause need a biopsy, because a few are precancerous. Updated Nov 12, 2026 ## Key points - Wipes off = candidiasis; does not = keratosis, lichen planus, leukoplakia or cancer. - Red is riskier than white. - Biopsy anything that persists beyond three weeks after removing causes. ## What it is A white lesion looks white because of thickened keratin, a surface pseudomembrane or scarring; a red lesion is red because the epithelium is thin or the vessels are dilated or inflamed. The first question is whether it wipes off: pseudomembranous candidiasis does, leaving a red base. Non-wiping white lesions range from harmless frictional keratosis and linea alba to lichen planus, hairy leukoplakia and leukoplakia, a clinical term for a white patch that cannot be characterised as any other condition and carries a risk of cancer. Erythroplakia (a velvety red patch) carries the highest risk of dysplasia or carcinoma. ## Red flags - Red or mixed red-white patches (erythroplakia, speckled leukoplakia) are the most worrying. - Induration, ulceration, bleeding or growth suggest carcinoma. - High-risk sites: lateral and ventral tongue, floor of mouth, soft palate. - Risk factors: tobacco, alcohol, areca nut, previous oral cancer, immunosuppression. - Hairy leukoplakia on the side of the tongue suggests HIV or another cause of immunosuppression. ## Step-by-step approach - Ask about duration, pain, tobacco, alcohol, areca nut, dentures, sharp teeth and HIV or transplant status. - Try to wipe the lesion with gauze: if it comes off, think of candidiasis. - Look for a cause at the site: a sharp tooth, a denture, cheek biting, a hot or chemical burn. - Look for a pattern: lacy white lines on both cheeks (lichen planus), corrugated plaques on the lateral tongue (hairy leukoplakia). - Remove any cause and review in two to three weeks; biopsy what persists. ## Keys to the differential - Frictional keratosis disappears within weeks after the irritant is removed; leukoplakia does not. - Lichen planus is bilateral and symmetrical; leukoplakia is usually a single patch. - A white patch with an ulcer or a firm base is cancer until proven otherwise. ## Next step / Initial management - Wipeable patch: treat as candidiasis and look for the cause (inhaled steroid, dentures, diabetes, antibiotics, immunosuppression). - Non-wipeable patch with a clear cause: remove the cause, review in two to three weeks. - Persistent patch, any erythroplakia, ulcer, induration or growth: refer for biopsy, urgently if features suggest cancer. - Hairy leukoplakia: offer an HIV test. ## Test yourself Think of the answer, then tap the question to see it. ## What simple test separates pseudomembranous candidiasis from other white lesions? Wiping with gauze: candidiasis comes off and leaves a red base. ## Which oral patch carries the highest risk of dysplasia or cancer? Erythroplakia, a red velvety patch. ## What should hairy leukoplakia on the lateral tongue prompt? An HIV test, because it signals immunosuppression and Epstein–Barr virus replication. [Add to my cards (3)](https://durgical.app/estudiar/?add=/en/dentistry/white-and-red-patches-in-the-mouth-approach/) ## Elsewhere in DurgiPedia - [Oral premalignant lesions: leukoplakia and erythroplakia](https://durgical.com/en/ent/oral-premalignant-lesions-leukoplakia-and-erythroplakia/) - [Approach to mouth ulcers](https://durgical.com/en/ent/approach-to-mouth-ulcers/) ## Connections ## Related 4 - [Oral candidiasis (thrush)](https://durgical.com/en/dentistry/oral-candidiasis/) - [Oral lichen planus](https://durgical.com/en/dentistry/oral-lichen-planus/) - [Oral cancer screening: who, what to look for, when to biopsy](https://durgical.com/en/dentistry/oral-cancer-screening-who-what-to-look-for-when-to-biopsy/) - [The systematic oral exam: outside in](https://durgical.com/en/dentistry/the-systematic-oral-exam-outside-in/) ## Related conditions 2 - [Head and neck squamous cell carcinoma (oral cavity and oropharynx, HPV)](https://durgical.com/en/conditions/head-and-neck-squamous-cell-carcinoma/) - [Lichen planus](https://durgical.com/en/conditions/lichen-planus/) [← All of dentistry](https://durgical.com/en/dentistry/) Educational content; it does not replace assessment by a dentist or doctor and is not a clinical instruction. For facial or neck swelling with difficulty swallowing or breathing, a knocked-out tooth or bleeding that will not stop, go to an emergency department at once. Sources: [Benign Chronic White Lesions of the Oral Mucosa](https://www.ncbi.nlm.nih.gov/books/NBK570596/) (StatPearls Publishing (NCBI Bookshelf), 2024); [Premalignant Lesions of the Oral Mucosa](https://www.ncbi.nlm.nih.gov/books/NBK572155/) (StatPearls Publishing (NCBI Bookshelf), 2023); [Oral Leukoplakia](https://www.ncbi.nlm.nih.gov/books/NBK442013/) (StatPearls Publishing (NCBI Bookshelf), 2023); [Hairy Leukoplakia](https://www.ncbi.nlm.nih.gov/books/NBK554591/) (StatPearls Publishing (NCBI Bookshelf), 2023). ## **Spotted a mistake?** We are always improving for the community. Tell us what is wrong and our team will review it. Report a mistake Representative model, for educational purposes only. --- Source: https://durgical.com/en/dentistry/white-and-red-patches-in-the-mouth-approach/ License: CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Cite as: DurgiPedia (durgical.com), https://durgical.com/en/dentistry/white-and-red-patches-in-the-mouth-approach/