22nd April 2024

Diseases of the Mouth and Salivary Glands

Oral infections

Fungal Disease of the mouth

Candidiasis is a fungal infection that is caused by the overgrowth of Candida species, the most common of which is Candida albicans. While Candida naturally resides on the skin and mucous membranes without causing harm in most individuals, certain conditions can lead to its proliferation and subsequent infection. The severity and manifestations of candidiasis can vary depending on the immune status of the affected individual, with immunocompetent and immunocompromised individuals presenting distinct clinical phenotypes. Patients with dentures or diabetes can be put at an augmented risk of oral candida. Immunocompetent individuals are capable of mounting an effective defence against Candida. In these individuals, candidiasis characteristically occurs in localised areas such as the oral cavity, known as oral thrush, as well as the vaginal area in women. Symptoms of infection may include white patches or plaques, pruritus, and discomfort in the affected areas. Immunocompetent individuals with candidiasis usually respond well to treatment with topical or oral antifungal agents, and the infection is generally self-limiting. Immunocompromised individuals allow Candida to invade deeper tissues and organs, leading to invasive candidiasis. This condition can occur in patients with underlying medical conditions such as HIV/AIDS, cancer, organ transplantation, or those receiving immunosuppressive therapy. Invasive candidiasis can manifest as bloodstream infections (candidemia), disseminated infections, or localised infections in specific organs such as the kidneys, liver, or lungs. Disseminated candidiasis requires intravenous fungal agents as well as a multidisciplinary approach involving infectious disease specialists, microbiologists, and other healthcare professionals, to guide appropriate treatment and monitor the response to therapy.

Viral and Bacterial Infections of the Mouth

Herpes Simplex Virus (HSV) infections are caused by two types of viruses: HSV-1 and HSV-2. HSV-1 primarily causes oral infections, while HSV-2 is associated with genital infections, although both viruses can infect either location. HSV-1 infections can be transmitted through direct contact with oral secretions. HSV infections in the mouth habitually present as painful fluid-filled blisters or ulcers on the lips, tongue, gums, or inside the cheeks. These lesions are often accompanied by local inflammation, discomfort, and mild systemic symptoms, such as fever and malaise. The primary infection can be severe, with multiple lesions and more systemic symptoms, while recurrent infections tend to be milder. Diagnosis of oral HSV infections is based on clinical presentation and can be confirmed through viral culture, polymerase chain reaction testing, or serological assays. Management focuses on symptomatic relief and includes antiviral medications, such as acyclovir, which help to reduce the duration and severity of outbreaks. Coxsackievirus infections can also lead to various oral manifestations, including herpangina and hand, foot, and mouth disease (HFMD). Herpangina presents as small, painful ulcers on the back of the throat, while HFMD results in ulcers on the tongue, gums, and inner cheeks.

Bacterial infections in the oral cavity, particularly dental abscesses, are common and can lead to significant oral health issues. Dental abscesses are localised collections of pus that form within the teeth or surrounding tissues. These infections, if left untreated, can result in severe pain, swelling, and potentially systemic complications such as infective endocarditis. Dental abscesses typically originate from dental caries (tooth decay) or periodontal disease. Streptococcus mutans, a common bacterium found in dental plaque, is frequently associated with the initiation and progression of dental caries. As caries progress, bacteria can penetrate the tooth structure and infect the dental pulp, leading to the formation of an abscess. Diagnostic imaging techniques, such as dental X-rays or orthopantomogramme may be employed to assess the extent of the infection and identify any underlying dental pathology. Antibiotics are commonly prescribed to control the infection.

References

• Ahuja NA, Kedia SK, Ward KD, Pichon LC, Chen W, Dillon PJ, Navaparia H. Effectiveness of Interventions to Improve Oral Cancer Knowledge: a Systematic Review. J Cancer Educ. 2022 Jun;37(3):479-498. doi: 10.1007/s13187-021-01963-x. Epub 2021 Jan 27. PMID: 33506408.
• Flynn TR, Shanti RM, Hayes C, et al. Contemporary concepts in the diagnosis and management of odontogenic infections. Oral Maxillofac Surg Clin North Am. 2011;23(3):443-452. doi:10.1016/j.coms.2011.05.003
• Kullberg BJ, Arendrup MC. Invasive candidiasis. N Engl J Med. 2015;373(15):1445-1456
• Pappas PG, Kauffman CA, Andes DR, et al. Clinical Practice Guideline for the Management of Candidiasis: 2016 Update by the Infectious Diseases Society of America. Clin Infect Dis. 2016;62(4):e1-e50
• Scully C. Orofacial Herpes Simplex Virus Infections—Update on Current Concepts of Viral Pathogenesis and Disease Management. Oral Surg Oral Med Oral Pathol Oral Radiol. 2019;127(4):340-350. doi:10.1016/j.oooo.2018.12.004.

Oral mucosal disorders

Oral Lichen Planus

This is a chronic inflammatory disorder illustrated by white, reticular, or erosive lesions forming a lace-like pattern (Wickham’s striae) that primarily affect the oral mucosa. The exact aetiology remains unknown, although it is believed to involve autoimmune mechanisms triggered by various factors such as stress, genetics, and viral infections. The lesions are occasionally bilateral and symmetrical and can be accompanied by symptoms of pain, burning sensation, and altered taste. Biopsy of the lesion may reveal characteristic features such as sawtooth-shaped rete ridges, lymphocytic infiltration and basal cell degeneration. Treatment involves the use of topical corticosteroids, immunomodulatory agents, and meticulous oral hygiene practices to control symptoms and prevent disease progression.

Image Source: Frontiers (2022). fmed-09-997190-g001, Licensed under a creative commons licence. Available for free at: https://www.frontiersin.org/files/Articles/997190/fmed-09-997190-HTML/image_m/fmed-09-997190-g001.jpg (Accessed: 23 January 2024)

Erythroplakia

Erythroplakia is a possible malignant disorder distinguished by red, velvety patches or plaques that cannot be attributed to any specific pathological condition. It is considered a high-risk lesion due to its strong association with oral squamous cell carcinoma. The exact aetiology of erythroplakia is not fully understood, but risk factors include tobacco use, alcohol consumption, chronic irritation, and HPV infection. The critical aspect of managing erythroplakia is its prompt identification and referral for biopsy. Excisional biopsy or incisional biopsy is performed to establish a definitive diagnosis and exclude malignancy. Treatment involves complete removal of the lesion, and patients should be closely monitored for recurrence or malignant transformation.

Image Source: NIH (2014). 25242838, Licensed under a creative commons licence. Available for free at: https://pubmed.ncbi.nlm.nih.gov/25242838/#&gid=article-figures&pid=figure-2-uid-1 (Accessed: 23 January 2024).

Leukoplakia

Leukoplakia refers to a white patch or plaque that cannot be branded as any other disease. Like erythroplakia, it is considered a potentially malignant disorder, with a significant proportion of cases progressing to oral squamous cell carcinoma. The primary etiological factors associated with leukoplakia include tobacco use, alcohol consumption, chronic irritation, and viral infections. Clinical diagnosis of leukoplakia is based on the identification of a white patch that cannot be scraped off and persists for more than two weeks. A biopsy is essential to establish a definitive diagnosis and exclude malignancy. Management involves eliminating or managing the underlying causative factors, such as smoking cessation, alcohol abstinence, and meticulous oral hygiene. Surgical excision or laser treatment may be necessary for dysplastic or high-risk lesions.

Image Source: Research Gate (2022). Homogenous leukoplakia involving the left dorsal/lateral tongue, Licensed under a creative commons licence. Available for free at: https://www.researchgate.net/figure/Homogenous-leukoplakia-involving-the-left-dorsal-lateral-tongue-image-provided-by-Guys_fig1_363796414 (Accessed: 23 January 2024).

Oral cancer

Oral cancer comprises a group of malignancies affecting the lips, tongue, cheeks, floor of the mouth, and other oral structures. The majority of oral cancers are squamous cell carcinomas. The most significant risk factors include tobacco use, heavy alcohol consumption, HPV infection (particularly high-risk strains such as HPV-16 and HPV-18), sun exposure (lip cancer), older age, male gender, a history of precancerous oral lesions, a weakened immune system, and a family history of oral cancer. Common symptoms of oral cancer include persistent mouth sores, red or white patches in the mouth, a lump or thickening of the oral tissues, difficulty swallowing or chewing, persistent sore throat, hoarseness, unexplained bleeding, numbness or pain in the mouth or lips, loose teeth, and changes in speech. Early detection through regular oral examinations is crucial for improving survival rates. Treatment modalities encompass surgery, radiation therapy, and chemotherapy, often used in combination.

Aphthous ulcers

Aphthous ulcers, also known as canker sores, are common painful, round, or oval-shaped oral lesions that develop on the mucous membranes of the mouth. The exact cause of aphthous ulcers remains unknown, but multiple factors are believed including genetic predisposition, immunological factors, trauma, and dietary factors. Although aphthous ulcers cannot be completely cured, several management strategies aim to alleviate symptoms, promote healing, and prevent recurrence such as pain relief, topical treatments, good oral hygiene, avoiding irritants and stress management. Recurrent aphthous-like ulcers are the hallmark of Behçet’s disease, a complex systemic vasculitis. They tend to be larger, deeper, and more persistent compared to typical aphthous ulcers. Healing of these ulcers often leads to scarring and may result in limited mouth opening or deformities.

References

• Warnakulasuriya S, Johnson NW, van der Waal I. Nomenclature and classification of potentially malignant disorders of the oral mucosa. J Oral Pathol Med. 2007;36(10):575-580.
• McCartan BE, Healy CM. The reported prevalence of oral lichen planus: a review and critique. J Oral Pathol Med. 2008;37(8):447-453.
• Fox, R. I. Sjögren’s syndrome. The Lancet, (2005). 366(9482), 321-331.
• Chavan M, Jain H, Diwan N, Khedkar S, Shete A, Durkar S. Recurrent aphthous stomatitis: A review. J Oral Pathol Med. 2012;41(8):577-583.

Salivary Gland Disorders

Salivary gland disorders encompass a range of conditions, including salivary gland infections (sialadenitis), salivary gland stones (sialolithiasis), and salivary gland tumours. Sialadenitis typically presents with pain, swelling, and tenderness. Sialolithiasis can cause intermittent or persistent swelling and pain in the affected gland. Tumours can be benign or malignant, with symptoms including a painless mass, facial nerve weakness, or changes in salivary gland function. Treatment depends on the underlying aetiology and may involve antibiotics, stone removal, or surgical excision.

References

• Ahuja NA, Kedia SK, Ward KD, Pichon LC, Chen W, Dillon PJ, Navaparia H. Effectiveness of Interventions to Improve Oral Cancer Knowledge: a Systematic Review. J Cancer Educ. 2022 Jun;37(3):479-498. doi: 10.1007/s13187-021-01963-x. Epub 2021 Jan 27. PMID: 33506408
• Flynn TR, Shanti RM, Hayes C, et al. Contemporary concepts in the diagnosis and management of odontogenic infections. Oral Maxillofac Surg Clin North Am. 2011;23(3):443-452. doi:10.1016/j.coms.2011.05.003

Oral Manifestations of Systemic Diseases

Endocrine Disorders

Poorly controlled diabetes can lead to periodontal disease, xerostomia (dry mouth), burning mouth syndrome, impaired wound healing, and increased susceptibility to infections such as oral candidiasis. These conditions can be attributed to the altered host response, impaired immune function, and changes in saliva composition associated with the disease. Patients with hypothyroidism may experience macroglossia (enlarged tongue), delayed tooth eruption, and altered taste sensation. These oral findings are thought to be connected with metabolic changes and reduced salivary flow rate in hypothyroidism.

Hematologic & Nutritional Disorders

Oral manifestations of anaemia (both iron and vitamin B12 deficiency) may include pale mucosa, glossitis (inflammation of the tongue), angular cheilitis (cracks and sores at the corners of the mouth), and oral ulcerations. These oral signs result from reduced oxygen-carrying capacity and tissue hypoxia associated with anaemia. Leukaemia can present with oral manifestations such as gingival enlargement, oral petechiae, spontaneous bleeding, oral ulcers, and increased susceptibility to infections. These oral findings can occur due to leukemic infiltration of oral tissues, impaired platelet function, and compromised immune response.

Autoimmune, Gastrointestinal & Immunologic Disorders

Sjögren’s syndrome is an autoimmune disorder characterised by dry mouth and dry eyes. The oral manifestations classically include xerostomia, dental caries, oral candidiasis, and mucosal ulcers. These symptoms are a consequence of decreased salivary gland function and can significantly impact oral health and quality of life.

Crohn’s disease can have oral manifestations that include orofacial granulomatosis, which is characterised by lip swelling, facial swelling, oral ulcers, and gingival hyperplasia. These manifestations may precede gastrointestinal symptoms and can aid in early diagnosis.

Oral manifestations of the disease are common in individuals with HIV/AIDS and can include oral candidiasis, oral hairy leukoplakia, periodontal disease, aphthous ulcers, Kaposi’s sarcoma, and salivary gland dysfunction. These manifestations often indicate a compromised immune system and can serve as markers for disease progression.

References

• Hietanen, J., & Salo, T. (2017). Oral manifestations of hypothyroidism: a review and case report. Acta Odontologica Scandinavica, 75(1), 1-6
• American Diabetes Association. (2003). Consensus Development Conference on Diabetic Complications: Oral Health Consensus Statement. Diabetes Care, 26(2), 593-598
• Bánóczy, J., & Jáhn, A. (2006). Oral manifestations of gastrointestinal diseases. Orvosi Hetilap, 147(25), 1187-1194