Itchy Scalp: What Are the Possible Causes? Answers From a Dermatologist

1. Dry Scalp

One of the most frequent causes of scalp itching is simple dryness. Cold weather, excessive washing, harsh shampoos, and hot showers can strip the scalp of its natural oils.

Signs to look for:

• Fine, white flakes
• Tight or uncomfortable scalp
• Itching without redness or inflammation

What helps: Use gentle, sulfate-free shampoos and moisturizing conditioners. Reducing wash frequency and avoiding hot water can also make a difference.

2. Dandruff (Seborrheic Dermatitis)

Dandruff is caused by an overgrowth of yeast that naturally lives on the scalp. It often leads to itching, flaking, and redness.

Signs to look for:

• Yellow or white flakes
• Greasy patches
• Red, irritated skin

What helps: Medicated shampoos containing zinc pyrithione, ketoconazole, or selenium sulfide are often recommended by dermatologists.

3. Allergic Reactions or Contact Dermatitis

Hair dyes, styling products, fragrances, and preservatives can trigger allergic reactions on the scalp.

Signs to look for:

• Sudden itching after using a new product
• Burning or stinging sensation
• Redness or swelling

What helps: Stop using the suspected product immediately. Patch testing by a dermatologist may be needed to identify the trigger.

4. Scalp Psoriasis

Psoriasis is a chronic autoimmune condition that can affect the scalp, causing thick, scaly patches and intense itching.

Signs to look for:

• Thick silvery scales
• Red plaques that may extend beyond the hairline
• Flaking that doesn’t improve with regular dandruff treatments

What helps: Prescription treatments such as topical corticosteroids, vitamin D analogs, or medicated shampoos may be necessary.

5. Fungal Infections (Tinea Capitis)

More common in children but possible in adults, fungal infections of the scalp can cause itching, scaling, and hair loss.

Signs to look for:

• Patchy hair loss
• Scaly or inflamed areas
• Broken hairs or “black dots”

What helps: Oral antifungal medication prescribed by a doctor is usually required.

6. Head Lice

While less common in adults, head lice can cause intense scalp itching due to allergic reactions to lice saliva.

Signs to look for:

• Severe itching, especially behind the ears and neck
• Small white nits attached to hair shafts

What helps: Over-the-counter or prescription lice treatments and thorough cleaning of personal items.