SymptomSkin, hair & nails
Scalp Redness: Causes and Treatment
Scalp redness is inflamed, pink or red skin on the scalp, often with itching, flaking or burning. The most common causes are seborrheic dermatitis (red skin with greasy yellow dandruff), scalp psoriasis (thick, silvery, well-defined plaques), and contact dermatitis from hair dye or shampoo. Sunburn, folliculitis and fungal infection are other causes. Most respond to medicated shampoos and topical treatments. Redness with hair loss in patches, pus or scarring should be seen by a doctor.
Also called: Red scalp, scalp erythema, inflamed scalp, irritated scalp
At a glance
- What it is
- Pink or red, inflamed skin on the scalp, often itchy or flaky.
- Common causes
- Seborrheic dermatitis, psoriasis, contact dermatitis, sunburn, folliculitis.
- Less common
- Scalp ringworm, lupus, lichen planopilaris, rosacea.
- How serious
- Usually a nuisance rather than dangerous; scarring hair loss needs prompt treatment.
- Treatment
- Medicated shampoos (ketoconazole, zinc, coal tar, salicylic acid), steroid solutions, avoiding triggers.
When to get help
Call 911 or go to the ER
- Sudden scalp redness and swelling with swelling of the face, eyes or throat, or trouble breathing after hair dye
See a doctor within a day or two
- Red, swollen, painful scalp with pus, fever or a boggy lump
- Severe blistering or burning after a chemical hair treatment or dye
- Painful blisters on one side of the scalp or forehead (possible shingles)
Book a routine appointment
- Red patches with hair loss, especially if the skin looks shiny or scarred
- Redness and scaling that does not improve after 4 weeks of medicated shampoo
- A red scalp in a child with broken hairs or scaly bald patches
- A red, scaly or crusted spot on a bald scalp that does not heal
Usually safe to manage at home
- Mild redness with greasy flakes that responds to anti-dandruff shampoo
- Mild sunburn on a part line or thinning scalp
How to tell the causes apart
| Cause | What it looks like | Other clues |
|---|---|---|
| Seborrheic dermatitis | Pink-red skin with greasy yellow or white flakes; fuzzy edges | Also eyebrows, sides of nose, behind ears; worse in winter and with stress |
| Scalp psoriasis | Thick, raised, red plaques with silvery scale; sharp edges | Often extends past the hairline; psoriasis on elbows, knees or nails |
| Contact dermatitis | Red, itchy or burning, sometimes weeping | Started after new dye, shampoo or product; may involve ears, neck, forehead |
| Sunburn | Red, tender, along the part or thinning areas | After sun exposure |
| Folliculitis | Red bumps or pustules around hair follicles | Itchy or tender, often at the back of the scalp |
| Scalp ringworm | Red, scaly patches with broken hairs | Mostly children; swollen neck glands |
| Discoid lupus, lichen planopilaris | Redness with scarring and permanent hair loss | Patchy, persistent, may be tender |
Seborrheic dermatitis
Seborrheic dermatitis is the most common cause of a red, flaky scalp in adults. It is an inflammatory reaction to Malassezia, a yeast that normally lives on oily skin. Severe dandruff is a mild form. In babies, it causes cradle cap. It tends to come and go, flaring with stress, cold weather and illness.
Scalp psoriasis
About half of people with psoriasis have it on the scalp. Plaques are thicker and more sharply defined than seborrheic dermatitis, with silvery scale that may bleed if picked. It can be very itchy. When features of both conditions overlap, doctors sometimes call it "sebopsoriasis".
Contact dermatitis
Contact dermatitis on the scalp is often allergic. The most common culprit is paraphenylenediamine (PPD) in permanent and semi-permanent dark hair dyes. Preservatives, fragrances and hair relaxers can also cause reactions. The scalp itself is quite resistant, so the rash often shows more on the forehead, ears, eyelids and neck. Severe PPD reactions can cause major facial swelling.
Folliculitis
Inflamed hair follicles appear as small red bumps or pus spots. Folliculitis can be bacterial, yeast-related, or caused by friction from hats, heavy oils and sweating.
Other causes
- Scalp ringworm: a fungal infection that mainly affects children.
- Rosacea: facial rosacea can extend onto a bald scalp.
- Scarring alopecias: discoid lupus and lichen planopilaris cause redness around follicles and permanent hair loss. Early treatment preserves hair.
- Sun damage: red, rough scaly spots on a bald scalp may be actinic keratoses, which can become skin cancer.
How doctors find the cause
A primary care doctor or dermatologist looks at the scalp, hairline, face, ears, nails and other skin areas. Questions cover products, dyes, triggers, family history of psoriasis and hair loss. Tests may include:
- a scalp scraping or plucked hairs for fungal culture
- patch testing to identify a contact allergy
- a small scalp biopsy if there is scarring, unusual redness or hair loss
Treatment
Seborrheic dermatitis
- Anti-yeast shampoos: ketoconazole 1 to 2%, selenium sulfide, zinc pyrithione or ciclopirox. Massage in and leave for 5 minutes, 2 to 3 times a week, then once a week to prevent flares.
- Short courses of steroid lotion or foam to calm severe redness and itch.
- Soften thick scale with mineral oil or olive oil before washing.
Scalp psoriasis
- Shampoos with coal tar or salicylic acid to lift scale.
- Prescription treatments: steroid solutions, foams or shampoos; vitamin D analog (calcipotriene) solutions; combination products.
- For severe or resistant cases: phototherapy, or systemic and biologic medicines that treat psoriasis throughout the body.
Contact dermatitis
- Stop the suspected product. Rinse thoroughly.
- Steroid lotion or, for severe reactions, steroid tablets prescribed by a doctor.
- Choose PPD-free dyes only after patch testing; people allergic to PPD may also react to some "natural" black henna.
General scalp care
- Use lukewarm, not hot, water.
- Avoid scratching and harsh brushing.
- Protect a thinning scalp from sun with a hat or scalp sunscreen.
- Avoid heavy oils if you are prone to folliculitis.
Frequently asked questions
Why is my scalp red and itchy?
The most common causes are seborrheic dermatitis (red skin with greasy flakes), scalp psoriasis (thick silvery plaques), and an allergic reaction to hair dye or another product. Folliculitis, sunburn and fungal infection are other possibilities. An anti-dandruff shampoo often helps the commonest cause.
How do I calm an inflamed scalp?
Stop any new hair products, wash with lukewarm water, and use a medicated shampoo containing ketoconazole, zinc pyrithione or selenium sulfide 2 to 3 times a week. If redness persists for 4 weeks or is severe, a doctor can prescribe a steroid lotion.
How can I tell scalp psoriasis from seborrheic dermatitis?
Psoriasis forms thick, raised plaques with silvery scale and sharp edges, often extending past the hairline, and usually appears elsewhere on the body. Seborrheic dermatitis has thinner, greasy, yellowish flakes with less defined edges and often affects the eyebrows and sides of the nose.
Can hair dye cause a red scalp?
Yes. Allergic reactions to hair dye, usually to the chemical PPD in dark dyes, cause redness, itching and burning on the scalp, forehead, ears and neck, sometimes with facial swelling. Patch test new dyes 48 hours before use, and seek urgent care for significant swelling.
Sources
This guide was written from current patient and clinical guidance, including:
- American Academy of Dermatology: Seborrheic dermatitis, diagnosis and treatment
- American Academy of Dermatology: Scalp psoriasis
- National Psoriasis Foundation: Scalp psoriasis
- NHS: Seborrhoeic dermatitis
- MedlinePlus: Contact dermatitis