Really Bad Scalp Skin Irritation. “the medical condition of dandruff is caused by an overgrowth of yeast,” says jessica wu, m.d., assistant clinical professor of. Braiding your hair too tight some hairstyles cause scalp irritation due to hair braiding.
Dandruff is the most common culprit to blame for an itchy scalp. Hormones can also cause acne. Stress, hormones, dry air, or cold weather can trigger psoriasis.