Yeast Infections

Yeast infections — most commonly caused by a yeast called Candida — are very common. Candida lives naturally in small numbers on the skin, in the mouth, gut, and vagina; under certain conditions it overgrows and causes symptoms. Yeast infections are usually mild and easily treated. They are not sexually transmitted infections.

Common types

• Vaginal yeast infection — common in women; itchy, thick white discharge
• Oral thrush — white patches in the mouth; common in babies, older adults, people using inhaled steroids (asthma), and those with weakened immunity
• Skin-fold infections (intertrigo) — in groin, armpits, under breasts; more common in hot, humid weather and in people with diabetes or overweight
• Nappy / diaper rash with candida in babies
• Nail infection — typically fingernails in people whose hands are often in water
• Invasive candidiasis — rare but serious bloodstream or organ infection, mostly in very ill hospitalised patients

Triggers for overgrowth

• Recent antibiotic use (disrupts normal flora)
• Diabetes, especially poorly-controlled
• Pregnancy
• Weakened immunity (HIV, chemotherapy, steroids)
• Tight, non-breathable clothing; damp undergarments
• Hot humid climate
• Oral contraceptives (for some women)

Symptoms

Depend on the site:

• Vaginal: itching, thick white "cottage cheese" discharge, burning with urination or sex
• Oral thrush: white patches on tongue and inner cheeks, soreness, difficulty swallowing
• Skin folds: red itchy rash, sometimes with smaller satellite spots around the main area
• Nails: swollen, tender skin around the nail; thickened, discoloured nails

Treatment

• Topical antifungal creams, pessaries, or ointments — over-the-counter or prescribed, used for 1-14 days depending on product and site
• Oral antifungal — single-dose or short-course for severe or recurrent infections
• Oral thrush — antifungal oral gel or suspension
• Keep skin folds dry — gentle drying, loose cotton clothing, antifungal powder
• Address triggers — stop unnecessary antibiotics, control diabetes, change out of damp clothes promptly

When to see a doctor

• First-time yeast infection (to confirm diagnosis)
• Symptoms don't improve after over-the-counter treatment
• Recurrent infections (4 or more vaginal infections a year)
• Pregnancy
• Diabetes or weakened immunity
• Severe symptoms, fever, or widespread rash