Oral Fungal Infections

Definition | Oral Candidiasis | Chronic Hyperplastic Candidiasis | Angular Cheilitis | Denture Stomatitis | References

Definition

Oral fungal infections are infections of the oral cavity caused by fungi, most commonly Candida species. These infections can affect various parts of the mouth and present with different clinical features.

Oral Candidiasis

Definition: Oral candidiasis, also known as thrush, is a fungal infection of the mouth caused by Candida species, most commonly Candida albicans.

Aetiology: Overgrowth of Candida species due to factors such as immunosuppression, antibiotic use, diabetes, or poor oral hygiene.

Pathophysiology: Candida species, which are normally present in the oral cavity, can overgrow and cause infection when the local or systemic immune defences are compromised.

Risk Factors: Immunocompromised state (e.g., HIV/AIDS, chemotherapy), diabetes, use of antibiotics or corticosteroids, poor oral hygiene, wearing dentures.

Signs and Symptoms: White, creamy plaques on the mucous membranes of the mouth, which can be wiped off to reveal erythematous or bleeding areas underneath. Other symptoms may include a burning sensation, altered taste, and discomfort.

Investigations: Clinical examination, microscopic examination of a smear from the lesion, fungal culture if necessary.

Management:

• Topical antifungal agents (e.g., nystatin suspension, clotrimazole lozenges)
• Systemic antifungal therapy for severe or refractory cases (e.g., fluconazole)
• Addressing underlying risk factors (e.g., improving oral hygiene, controlling diabetes, reviewing medications)
• Referral to a specialist if the infection is severe or recurrent

Chronic Hyperplastic Candidiasis

Definition: Chronic hyperplastic candidiasis, also known as candidal leukoplakia, is a persistent fungal infection of the oral mucosa characterised by white plaques that cannot be scraped off.

Aetiology: Chronic irritation and immunosuppression contribute to the persistence of Candida infection in the oral cavity.

Pathophysiology: Chronic infection leads to hyperplasia of the epithelial layer, forming thick, white plaques.

Risk Factors: Smoking, immunosuppression, poor oral hygiene.

Signs and Symptoms: White, adherent plaques on the oral mucosa, particularly on the buccal mucosa and tongue. These plaques cannot be wiped off and may cause discomfort or a burning sensation.

Investigations: Clinical examination, biopsy of the lesion for histopathological examination, fungal culture.

Management:

• Topical antifungal agents (e.g., miconazole gel)
• Systemic antifungal therapy for severe cases (e.g., itraconazole)
• Smoking cessation support
• Improvement of oral hygiene
• Regular monitoring for malignant transformation
• Referral to a specialist if the infection is refractory or there is suspicion of malignancy

Angular Cheilitis

Definition: Angular cheilitis is an inflammatory condition affecting the corners of the mouth, often associated with Candida infection.

Aetiology: Overgrowth of Candida species, often in combination with bacterial infection (e.g., Staphylococcus aureus).

Pathophysiology: Moisture and maceration at the corners of the mouth create an environment conducive to fungal and bacterial growth, leading to inflammation and infection.

Risk Factors: Denture wearers, advanced age, immunosuppression, nutritional deficiencies (e.g., iron, vitamin B).

Signs and Symptoms: Redness, fissures, and soreness at the corners of the mouth. Crusting and bleeding may occur.

Investigations: Clinical examination, swab for culture to identify causative organisms.

Management:

• Topical antifungal agents (e.g., miconazole cream)
• Topical antibacterial agents if bacterial infection is present (e.g., fusidic acid cream)
• Addressing underlying causes (e.g., fitting dentures properly, correcting nutritional deficiencies)
• Maintaining good oral and peri-oral hygiene
• Referral to a specialist if the condition is recurrent or resistant to treatment

Denture Stomatitis

Definition: Denture stomatitis is an inflammatory condition of the oral mucosa underlying a denture, often associated with Candida infection.

Aetiology: Poor denture hygiene, continuous denture wear, overgrowth of Candida species.

Pathophysiology: Chronic irritation and colonisation by Candida species lead to inflammation of the denture-bearing mucosa.

Risk Factors: Wearing dentures continuously, poor oral and denture hygiene, smoking, diabetes.

Signs and Symptoms: Redness and swelling of the mucosa beneath the denture, sometimes accompanied by soreness or discomfort.

Investigations: Clinical examination, swab for fungal culture if necessary.

Management:

• Improving denture hygiene (e.g., regular cleaning and soaking)
• Topical antifungal agents (e.g., nystatin cream)
• Encouraging patients to remove dentures at night
• Addressing underlying risk factors (e.g., smoking cessation, controlling diabetes)
• Referral to a dentist or specialist if necessary for denture adjustment or further management

References

1. NICE. (2024). Oral and Dental Health: Assessment and Management. Retrieved from NICE
2. NHS. (2023). Oral Thrush in Adults. Retrieved from NHS
3. British Medical Journal (BMJ). (2022). Oral Fungal Infections: Diagnosis and Management. Retrieved from BMJ
4. American Dental Association (ADA). (2021). Clinical Practice Guideline: Oral Fungal Infections. Retrieved from ADA

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