Malassezia furfur. Malaysia bubur.

The severity of dandruff may fluctuate with season as it often worsens in winter.

Those affected by dandruff find that it can cause social or self-esteem problems.

Treatment may be important for both physiological and psychological reason.

There is some evidence that excessive perspiration and climate have significant roles in the pathogenesis of dandruff.

 Redness and itching is actually seborrheic dermatitis, and it frequently occurs around the folds of the nose and the eyebrow areas, not just the scalp.

Seasonal changes, stress, and immuno-suppression seem to affect seborrheic dermatitis.

Like other skin conditions, hot water can exacerbate dandruff or itching. Using slightly cooler water (not cold) during regular hair washing and rinsing has been found to reduce dandruff in some individuals.

Stress, fatigue, weather extremes, oily skin, infrequent shampoos or skin cleaning, use of lotions that contain alcohol, skin disorders (such as acne), or obesity may increase the risk.

Commonly affected areas include the scalp, eyebrows, eyelids, creases of the nose, lips, behind the ears, in the outer ear, and middle of the chest.

You can treat flaking and dryness with over-the-counter dandruff or medicated shampoos. Shampoo the hair vigorously and frequently (preferably daily). Loosen scales with the fingers, scrub for at least 5 minutes, and rinse thoroughly. Active ingredients in these shampoos include salicylic acid, coal tar, zinc, resorcin, ketoconazole, or selenium.

Seborrheic dermatitis may improve in the summer, especially after outdoor activities.

Seborrheic dermatitis is a chronic (life-long) condition that can be controlled with treatment. It often has extended inactive periods followed by flare-ups. A more extreme form of this condition overlaps with psoriasis of the scalp and is called sebopsoriasis.

The severity of seborrheic dermatitis can be lessened by controlling the risk factors and by paying careful attention to skin care.

In more rare cases, redness and flaking may occur on the skin near the eyelashes, on the forehead or around the sides of the nose.

A sign that the condition has become more severe is the formation of thick, oily and yellow scales which might appear on the forehead, around the sides of the nose or on the skin near the eyelashes. 

It's not my problem but it's also my concern.

You can tell. 

@__________@

Reference. :| and wikipedia.