1. Seborrheic Dermatitis (a.k.a. dandruff and its more stubborn cousin)

This is by far the most common culprit. It isn't caused by being "dirty," dry hair, or poor hygiene. Instead, it's an inflammatory reaction to a yeast (Malassezia) that naturally lives on the scalp.

Clues: Flakes, redness, itch, worse in colder months.

Best Treatments:

• Rotate medicated shampoos: ketoconazole, zinc pyrithione, selenium sulfide, coal tar, or salicylic acid.
• Leave on 3–5 minutes before rinsing.
• For more stubborn cases, dermatologists prescribe topical steroids or calcineurin inhibitors.

2. True Dry Scalp (less common than people think)

Most "dry scalp" isn't actually dryness—it's inflammation. But true xerosis can happen, especially with over-washing or harsh products.

Clues: Tightness, fine white flakes, no redness.

Best Treatments:

• Switch to gentle, sulfate-free shampoos.
• Add scalp oils formulated for dermatologic use (jojoba or squalane), not random pantry oils that occlude follicles or worsen seborrhea.
• Reduce heat styling.

3. Contact Dermatitis (reaction to hair products)

Fragrances, preservatives, dyes, and botanicals are common triggers—even in "clean beauty" lines.

Clues: Itch more than flaking, sensitivity to certain shampoos, new hair dyes, or styling products.

Best Treatments:

• Remove the offending product.
• Use hypoallergenic shampoos (think Free & Clear or Vanicream).
• For persistent reactions, patch testing with a dermatologist is the gold standard.

4. Psoriasis of the Scalp

A chronic autoimmune condition—very different from dandruff.

Clues: Thick, silvery scales; plaques beyond the hairline; family history.

Best Treatments:

• Prescription steroid solutions, vitamin D analogs, or combination therapies.
• For widespread disease, biologics may be needed.

Treatments to Avoid (TikTok Edition)

• Apple cider vinegar: can cause chemical burns.
• Tea tree oil undiluted: frequent cause of contact dermatitis.
• Coconut oil for "fungal flakes": often worsens seborrheic dermatitis.
• Scrubbing with brushes or scalp "detoxers": triggers more inflammation.

If something sounds like a kitchen recipe or a miracle cure, skip it.

When to See a Dermatologist

If your scalp is painful, bleeding, rapidly worsening, or failing to improve after 2–3 weeks of proper medicated shampoos, a dermatologist can quickly pinpoint the cause and tailor treatment—something no viral 15-second clip can do.