Systemic Diseases That Start in the Mouth

Little do we realise that the oral cavity is much more than teeth and gums. It often serves as the body’s first line of defence, where symptoms of systemic diseases are usually first observed.

Dentists who examine the mouth regularly can detect these early changes and guide patients toward timely medical care.

Why Systemic Disease Shows Up In The Mouth?

Most systemic diseases have oral manifestations initially because of high vascularity. It is prone to immune reactions and easily reflects metabolic changes.

Dental practitioners should be able to point out when the lesion is more than a local factor.

Here are the most common systemic diseases that begin in the mouth.

1. Nutritional Deficiencies

• Iron, folate, or vitamin B12 deficiency commonly presents as recurrent aphthous-like ulcers, atrophic glossitis, or burning mouth¹.
• These oral ulcers usually don’t respond to routine topical care.
• Dentists should consider recommending blood tests for nutritional status in case of recurrent or unexplained ulceration.

2. Autoimmune & Gastrointestinal Disorders

• Crohn’s disease can be seen in the form of cobblestoning of the oral mucosa, deep linear ulcers, or lip swelling. 
• The prevalence of oral symptoms ranges from 0.7% to 37% in adults and from about 7% to 23% in children².
• Ulcerative colitis & celiac disease can cause recurrent aphthae and angular cheilitis.
• Systemic lupus erythematosus (SLE) can occur in the form of erythematous patches or lichenoid lesions³. 
• Dentists should take note of such lesions and refer the patient to the required medical professional

3. Endocrine & Metabolic Conditions

• Diabetes mellitus can cause symptoms like xerostomia, recurrent candidiasis, burning mouth, or delayed wound healing⁴.
• Thyroid disease may present itself as macroglossia or mucosal edema.
• Recognising such oral symptoms of systemic diseases by dentists can expedite diagnosis and further treatment of conditions.

4. Hematological Disorders

• Leukemia can first appear as gingival enlargement, spontaneous bleeding, or petechiae⁵.
• These changes may mimic periodontal disease, but the progression is unusually fast.
• Any sort of unexplained gingival swelling or bleeding should be immediately referred. 

5. HIV & Immunosuppression

• HIV infection is known to present with symptoms of oral candidiasis, hairy leukoplakia, or persistent ulcers.
• Oral lesions can be seen in almost 50% OF HIV positive patients and almost 80% of AIDS patients⁶.
• Patients on long-term immunosuppressants are also at risk of infections and mucosal changes.
• Dentists should always notice any unusual, recurrent, or aggressive oral lesions. 

Red flags to never ignore

• Ulcers persisting for more than 3 weeks⁷. 
• Any unexplained gingival enlargement or bleeding.
• Rapid and unexplained enlargement of mucosal lumps.
• Persistent candidiasis that is unresponsive to therapy

Final Takeaway

The mouth often speaks before the body does. For dentists, the ability to spot systemic diseases that start in the mouth is not only about oral care; it is about saving lives. By linking oral patterns with systemic disease, documenting carefully, and referring early, dentists can fulfil their role as vital gatekeepers of patient health.

References

1. Boukssim S, Chbicheb S. Oral manifestations of vitamin B12 deficiency associated with pernicious anemia: A case report. Int J Surg Case Rep. 2024 Jun 22;121:109931.
2. Lauritano D, Boccalari E, Di Stasio D, Della Vella F. Prevalence of oral lesions and correlation with intestinal symptoms of inflammatory bowel disease: a systematic review. Diagnostics (Basel). 2019;9(3):77.
3. Du F, Qian W, Zhang X, Zhang L, Shang J. Prevalence of oral mucosal lesions in patients with systemic lupus erythematosus: a systematic review and meta-analysis. BMC Oral Health. 2023;23:1030.
4. Rohani B. Oral manifestations in patients with diabetes mellitus. World J Diabetes. 2019 Sep 15;10(9):485-9.
5. Capodiferro S, Limongelli L, Favia G. Oral and maxillo-facial manifestations of systemic diseases: An overview. Medicina (Kaunas). 2021 Mar 16;57(3):271.
6. Lomelí-Martínez SM, González-Hernández LA, Ruiz-Anaya AJ, Lomelí-Martínez MA, Martínez-Salazar SY, Mercado González AE, Andrade-Villanueva JF, Varela-Hernández JJ. Oral manifestations associated with HIV/AIDS patients. Medicina (Kaunas). 2022 Sep 3;58(9):1214
7. NICE Guideline NG12 (2025). Suspected cancer: recognition and referral. https://www.nice.org.uk/guidance/ng12.