Candidiasis

Candida species are a normal part of the GI and GU flora as well as on the skin and nails, but at the same time they can be considered fungal pathogens when they have overgrowth. The most commonly implicated pathogen is candida albicans., a dimorphic fungus made of spherical yeast cells or elongated hyphae forms.

Recurrent candida infections (and candida infections in general) are more common in immunocompromised individuals (such as in diabetes or HIV).

In this CCC we will take a look at oral candidiasis, vulvovaginal candidiasis and skin candidiasis.

ORAL CANDIDIASIS

Oral candidiasis occurs as a result of pathological candida albicans colonisation. For candida to colonise the oral tissue, there needs to be some level of immune compromise. Usually salivary proteins and pH, antimicrobial proteins and T-cell mediated responses inhibit overgrowth of candida and infection.

🔢 + 😷 Classification and presentation

There are 4 main types of oral candidiasis:

1. Pseudomembranous candidiasis - this is commonly known as thrush.
1. It is associated with antibiotic use and immunosuppression.
2. It appears as a creamy white/yellow plaque adhered to the oral mucosa. Underneath this plaque there may be an erythematous or bleeding skin surface.
3. Most commonly found on the buccal mucosa, tongue, palate.
4. It may be acute or chronic.

2. Erythematous candidiasis - also known as atrophic oral candidiasis.
1. This is more common but often is clinically overlooked.
2. It is erythematous and flat without any plaques. There will be patches of atrophy of the filiform papillae on the tongue. It may be accompanied by a burning pain.
3. Once again may be acute or chronic.

3. Denture stomatitis
1. This is found under removable dentures. It occurs due to wearing dentures continuously without cleaning. However, there is some controversy wether or not it is a candida infection as dentures are positive for culture but mucosa is not.
2. It appears velvety or nodular and may have accompanying erythema or petechial haemorrhage.

4. Angular cheilitis
1. Cracking ulceration or fissures radiating from the corners of the mouth. The lesions are typically painful.
2. They are also associated with vitamin and nutrient deficiencies.

⚠️ Risk factors

🔍 Investigations

It is based on clinical diagnosis and exclusion of other differentials. Swabs may be done but are not useful as they are normal comensal microbes found in healthy people.

🧰 Management

VULVOVAGINAL CANDIDIASIS

Vulvovaginal candidiasis or commonly known as thrush or a yeast infection is a common infection of the female genitalia that most commonly arises due to Candida albicans (80%).

It occurs most commonly in women aged 20-40 years old.

Pathophysiology

Traditionally, we have seen candida infections as opportunistic infections. A new proposition is that it could also be as a result of hypersensitivity to candida. Genetic predisposition and levels of oestrogen are believed to play a part in this. More research needs to be made around this hypothesis, nevertheless.

⚠️ Risk factors

😷 Presentation

• Pruritus vulvae - itchiness of the vulva that can extend into the perineum.
• Cottage cheese discharge - white, lumpy discharge with a non-offensive smell (sour milk like).
• Superficial dyspareunia - pain at the vaginal opening during intercourse.
• Dysuria
• Erythema, fissuring satelite lesions, swelling - these may be seen on examination.

🔍 Investigations

• If the history is indicative of acute, uncomplicated vulvovaginal candidiasis → clinical diagnosis is sufficient. Uncomplicated thrush is one that has mild-moderate symptoms and is sporadic, not recurring and not associated with risk factors (as mentioned above).

If there are complicated cases (e.g. recurrent infection), we can order some investigations:

1. 🥇 High vaginal swab - for microscopy.
2. Vaginal pH testing of secretions - pH <4.5.
3. Midstream urine sample - if UTI is suspected.
4. HbA1c - to exclude diabetes in recurrent infections.
5. STI screen

🧰 Management

Acute vulvovaginal candidiasis management:

Self-management

1. Avoid contact with irritant soap, shampoos, shower gels etc.
2. Avoid vaginal douching
3. Avoid tight-fitting clothing

Antifungal treatment

There are many options and they can be chosen according to the patient’s age, comorbidities, preference, contraindications etc.

There are 3 types of treatments that can be given:

1. 🥇 Oral
1. NICE recommends fluconazole oral capsule 150mg single dose as the first-line option. If there are signs of severe infection a second dose can be given on day 4.
2. 🥈 Intravaginal (pessary device)
1. Clotrimazole intravaginal pessary 500mg as a single dose if oral fluconazole is contraindicated.
3. Topical vulval cream
1. If vulval symptoms are present, we can add a topical imidazole cream on top of the oral/intravaginal options:

Clotrimazole 1% or 2% (Canesten) applied 2-3 times a day. Advise that they may damage latex condoms and diaphragms.

⚠️ Pregnant women are advised to use only local treatments (creams or pessaries) as oral treatments are contraindicated.

CANDIDAL INTERTRIGO

Candidal intertrigo is a fancy way of saying candidal skin infection. It occurs in the skin folds most commonly due to a transient colonisation.

⚠️ Risk factors

😷 Presentation

It typically affects skin folds such as groin, inframammary folds, axillae, antecubital fossa, perineal, interdigital areas, neck creases.

It presents with:

• Erythema
• Soreness and itching
• Pustules with a red base may be present.
• Scales - a whitish-yellow, curd-like substance may appear over the infected area.

🔍 Investigations

Clinical diagnosis based on the appearance of skin and clinical features.

🧰 Management