Melasma occurs when multiple factors work together to increase pigment in the skin. Sun and visible light trigger pigment production and oxidative stress, while hormones like estrogen and progesterone make pigment cells more sensitive and active.
These cells produce excess melanin, which spreads into surrounding skin and appears as dark patches. Inflammation and increased blood flow can make pigmentation worse and longer-lasting, and a weakened skin barrier makes the skin more reactive to triggers. Overall, melasma is caused by sun exposure, hormones, inflammation, and skin sensitivity working together.
Heat can worsen melasma even without sun exposure by triggering inflammation and activating pigment cells. It increases signals in the skin—like VEGF and prostaglandins—that boost melanin production, and activates the TRPV1 (heat) receptor, which also drives pigmentation.
Repeated heat exposure, such as from cooking or hot environments, can keep this process going. Heat also works together with visible and infrared light to further increase pigmentation.

What Is Seborrheic Dermatitis?
Seborrheic dermatitis is a common, chronic skin condition (affecting ~2–5% of people) that causes redness, flaking, and itching, mainly in oil-rich areas like the scalp, face, chest, and skin folds. It’s not contagious, tends to come and go, and is more common in infants, adults 30–60, and men, and can be more severe in conditions like HIV or Parkinson’s disease.
It is caused by a mix of Malassezia yeast overgrowth, excess oil, inflammation, and a weakened skin barrier. The yeast feeds on oil, producing substances that irritate the skin and disrupt the barrier, leading to flaking and redness. Factors like genetics, weather, stress, and immune or neurologic conditions can trigger flares.

Treatment focuses on reducing yeast, calming inflammation, and repairing the skin barrier. Antifungals help control yeast, while soothing ingredients and ceramide moisturizers support the skin. Keeping the skin slightly acidic (pH ~4.5–5.5) helps prevent flares. In more severe cases, short courses of oral antifungals may be used.

TINEA VERSICOLOR (PITYRIASIS VESICOLOR)

Tinea versicolor is a common, chronic skin condition caused by an overgrowth of Malassezia yeast, which normally lives on the skin. Unlike seborrheic dermatitis or dandruff, it has minimal visible inflammation and appears as lighter or darker patches on the chest, back, shoulders, neck, and sometimes the face. It is not contagious and tends to flare in warm, humid conditions, especially in adolescents and young adults. The yeast thrives in oily, sweaty environments, and its byproducts can disrupt the skin barrier and affect pigment, leading to noticeable color changes.

The condition develops due to a combination of yeast overgrowth, excess oil, barrier dysfunction, and oxidative stress, which can damage pigment-producing cells and alter skin color. Factors like heat, sweating, tight clothing, genetics, and immune changes can increase risk.

Treatment focuses on reducing yeast and restoring skin balance, using antifungal topicals (such as ketoconazole, selenium sulfide, or ciclopirox), along with anti-inflammatory, antioxidant, and barrier-supporting skincare. Keeping the skin slightly acidic, cool, and dry also helps prevent recurrence.

SEBOPSORIASIS

Sebopsoriasis is a skin condition with features of both psoriasis and seborrheic dermatitis, often affecting oil-rich areas like the scalp, face, chest, and skin folds. It appears as red or purple patches with greasy, yellowish scales (less silvery than classic psoriasis) and may cause itching, burning, flaking, and sometimes hair loss. It develops from a mix of immune-driven inflammation (psoriasis) and Malassezia yeast activity with excess oil (seborrheic dermatitis), and can flare with stress, hormonal changes, cold weather, and fungal overgrowth.
Diagnosis is usually based on clinical appearance and location, with biopsy rarely needed. Treatment focuses on reducing yeast and inflammation, using antifungals (ketoconazole, ciclopirox), topical steroids for short-term control, and medicated shampoos like coal tar. In more severe cases, phototherapy may be used. Long-term management includes gentle skincare, stress control, and avoiding triggers.

Pityrosporum folliculitis, also called Malassezia folliculitis or fungal acne, is a common condition caused by an overgrowth of yeast that normally lives on the skin. It leads to itchy, small, uniform bumps or pustules, most often on the chest, back, shoulders, and face, and tends to flare with heat, sweating, oily skin, and tight clothing. Unlike regular acne, it does not have blackheads or whiteheads and often doesn’t improve with typical acne treatments—antibiotics may even make it worse.

This happens when the yeast overgrows in warm, humid, oil-rich environments, sometimes triggered by sweating, heavy skincare products, or recent antibiotic use. Diagnosis is usually based on how it looks and where it appears, especially when breakouts are itchy and resistant to acne therapy.

Treatment focuses on reducing yeast, calming inflammation, and supporting the skin barrier. Antifungal treatments are first-line, while ingredients like niacinamide and 18β-glycyrrhetinic acid help soothe the skin, and ceramide moisturizers support repair. Keeping the skin slightly acidic, cool, and dry helps prevent flares. A simple routine includes using an antifungal wash a few times per week, moisturizing daily, avoiding heavy oils, and showering after sweating.