INTRODUCTION
Oral candidiasis is an infection of the oral cavity caused primarily by Candida albicans.
It typically occurs secondary to immunosuppression—either local or systemic. Risk factors include extremes of age (newborns or elderly), immunocompromising conditions such as HIV/AIDS, and prolonged use of systemic steroids or antibiotics.
Local immunosuppression may occur due to the use of inhaled corticosteroids, commonly prescribed for the preventative treatment of asthma or COPD.
The most common form is acute pseudomembranous candidiasis, also known as thrush.
Diagnosis is primarily clinical, involving history taking and risk factor assessment.
Topical antifungal therapy combined with improved oral hygiene is usually sufficient to resolve mild candidiasis.
ETIOLOGY
Candida albicans is a dysmorphic yeast that can exist in both hyphal and yeast forms depending on the environment.
PATHOPHYSIOLOGY
Candida species cause oral candidiasis when host immunity is disrupted.
This may be due to local (e.g. corticosteroid inhaler use) or systemic factors.
Overgrowth of the fungus leads to the formation of a pseudomembrane.
In healthy individuals, the immune system and normal oral flora help inhibit Candida growth.
HISTORY AND PHYSICAL EXAMINATION
- White lesions: Seen in acute pseudomembranous candidiasis and chronic hyperplastic candidiasis.
- Red lesions: Seen in acute and chronic erythematous candidiasis, angular cheilitis, median rhomboid glossitis, and linear gingival erythema.
1. ACUTE PSEUDOMEMBRANOUS CANDIDIASIS
- Accounts for approximately one-third of all oral candidiasis cases.
- Common in newborns, elderly individuals, and immunocompromised patients.
- Risk factors: Inhaled corticosteroids, topical steroids (gels, rinses), and reduced salivary flow.
Clinical Features:
- Extensive white patches that are easily wiped away, leaving an erythematous mucosal surface.
- The pseudomembrane consists of desquamated epithelial cells, fibrin, and fungal hyphae.
Symptoms:
- May be asymptomatic.
- If symptomatic: burning sensation, oral bleeding, and altered taste perception.
- Commonly affects tongue, labial and buccal mucosa, gingiva, palate, and oropharynx.
2. CHRONIC HYPERPLASTIC CANDIDIASIS
- Presents as slightly raised, well-circumscribed white plaques, usually on the buccal mucosa, possibly extending to labial commissures.
- May appear speckled or nodular and cannot be wiped off.
- Often linked to smoking.
- Carries potential for progression to dysplasia or malignancy.
3. ACUTE ATROPHIC CANDIDIASIS
- Appears as generalized or localized erythema, most commonly on the palate, tongue, or buccal mucosa.
- Tongue atrophy may be observed.
- Patients may present with burning mouth or tongue.
- Differential diagnosis is important to rule out other causes.
4. CHRONIC ATROPHIC CANDIDIASIS (DENTURE STOMATITIS)
- Presents as localized erythema beneath dentures; can also be seen with orthodontic appliances.
- Risk factors include poor denture hygiene, wearing dentures 24/7, or ill-fitting dentures.
- Lesions are typically edematous and erythematous, limited to denture-contact areas.
- Often co-occurs with angular cheilitis.
Classification:
- Type 1: Petechial hemorrhage and localized inflammation
- Type 2: Diffuse erythema under dentures
- Type 3: Central erythema on the hard palate or papillary hyperplasia
5. MEDIAN RHOMBOID GLOSSITIS
- Rare. Characterized by a rhomboid-shaped erythematous patch in the midline of the tongue dorsum, anterior to the circumvallate papillae.
- Associated with Candida-induced atrophy of filiform papillae.
- Linked with smoking and inhaled steroid use.
- A corresponding palatal lesion (a “kissing lesion”) may indicate immunosuppression and can be a potential marker of HIV—warrants further investigation.
6. ANGULAR CHEILITIS
- Painful, erythematous, fissured patches at one or both corners of the mouth.
- Often bilateral.
- Results from accumulation of saliva in moist creases, favoring Candida growth.
- Predisposing factors include denture use, lip licking, deep wrinkles, and biting the commissure.
- May also be associated with nutritional deficiencies: iron, folic acid, riboflavin, thiamine, and vitamin B12.
7. LINEAR GINGIVAL ERYTHEMA
- Common in HIV patients; may indicate disease progression.
- Presents as a distinct erythematous band along the gingival margins of one or more teeth.
DIAGNOSIS
- Based on clinical examination, medical history, and assessment of risk factors.
- Diagnosis may include trial antifungal therapy and observation of response.
- Biopsy may be needed for lesions suspected of malignancy.
TREATMENT
- Depends on patient involvement and degree of immunosuppression.
- First-line: Topical antifungal therapy.
- Systemic therapy: Reserved for refractory or severe cases.
- Mild cases often respond to topical agents and improved oral hygiene.
Common antifungals:
- Nystatin
- Miconazole
- Clotrimazole
- Ketoconazole
DENTURE MANAGEMENT
- Essential for controlling denture stomatitis.
- Dentures should be cleaned daily and removed for at least 6 hours overnight.
- Soaking dentures in chlorhexidine and allowing them to air dry helps eliminate Candida.
- Hypochlorite solutions may be used for dentures with metal components.
DIFFERENTIAL DIAGNOSIS
Erythematous forms:
- Oral mucositis
- Thermal burns
- Anemia
Chronic hyperplastic candidiasis:
- Leukoplakia
- Lichen planus
- Pemphigoid
- Pemphigus
- Oral squamous cell carcinoma
PROGNOSIS
- Generally excellent with appropriate antifungal treatment and correction of predisposing factors.
PATIENT EDUCATION
- Patients using steroid inhalers should rinse their mouths after every use.
- Nutritional deficiencies (e.g., iron, B12) should be identified and appropriately treated.
References
Taylor, M., Brizuela, M., & Raja, A. (2023). Oral candidiasis. In StatPearls. StatPearls Publishing. https://www.ncbi.nlm.nih.gov/books/NBK545282/