Itchy Scalp with Flakes: Differential Diagnosis and Management

Pruritic, flaky scalp has several distinct etiologies requiring different treatments.

1. Seborrheic Dermatitis (Dandruff)

• Cause: Malassezia yeast overgrowth + host immune response.
• Features: Greasy, yellowish scales on erythematous base; scalp, face, chest.
• Triggers: Stress, cold/dry weather, neurological conditions (Parkinson's), HIV.
• Treatment: Antifungal shampoos (ketoconazole 2%, ciclopirox, selenium sulfide, zinc pyrithione) 2–3×/week; topical corticosteroids for flares.

2. Dry Scalp (Xerosis)

• Features: Fine, white, dry flakes; tightness; worse in winter.
• Treatment: Gentle shampoo, less frequent washing, scalp oils (coconut, jojoba), humidifier.

3. Psoriasis

• Features: Thick, silvery-white scales on well-demarcated erythematous plaques; often extends beyond hairline; Auspitz sign.
• Treatment: Tar/salicylic acid shampoos, topical steroids, calcipotriene, biologics (severe).

4. Tinea Capitis (Fungal)

• Features: Scaling, alopecia, black dots, kerion (boggy inflammation); mostly children.
• Treatment: Oral terbinafine/griseofulvin + antifungal shampoo.

5. Contact Dermatitis

• Allergic (hair dye/PPD, fragrances) or irritant (harsh shampoos).
• Patch testing identifies allergen.

6. Atopic Dermatitis

• Chronic, relapsing; personal/family history of atopy.

When to See a Dermatologist

• OTC shampoos fail after 4–6 weeks.
• Hair loss, pustules, crusting, spread beyond scalp.
• Suspected tinea capitis or psoriasis.