Seborrheic Dermatitis flaky face and scalp: what drives it, how it differs from dandruff, and what treats it

The basics

What seborrhoeic dermatitis is, and who gets it

Seborrhoeic dermatitis is an inflammatory skin condition of the oil-rich areas of the body: the scalp, face, ears, chest and skin folds. Estimates of how common it is range from about 1 to 3 per cent of the general population up to around 12 per cent, depending on how mild cases are counted. It has two peaks: babies, where it shows as cradle cap, and teenagers to middle-aged adults, more often men.

It is not an infection you catch, it is not a sign of being unclean, and it does not scar. It does tend to be chronic, settling for weeks or months and then returning. Doctors link more severe seborrhoeic dermatitis with some neurological conditions, such as Parkinson's disease, and with weakened immunity, including HIV, so a sudden, severe rash in an adult is worth a doctor's look.

Where it shows

Seborrheic dermatitis on the face and scalp

On the scalp it causes flaking, from fine dandruff-like scale to thicker, yellowish, greasy-looking patches, often with itch and redness along the hairline. On the face it typically affects the eyebrows, the skin between them, the creases beside the nose, the beard or moustache area and the edges of the eyelids, where it causes red, scaly lids (blepharitis). Behind and inside the ears is common too.

On the chest it can form ring- or petal-shaped flaky patches over the breastbone. In darker skin, patches may look paler than the surrounding skin rather than red. The face often feels oily and dry at the same time, which is why heavy moisturising alone rarely fixes it.

• Scalp and hairline: flaking, itch, redness at the hairline
• Eyebrows and the skin between them
• Creases beside the nose, moustache and beard area
• Eyelid edges: red, scaly lids (blepharitis)
• Ears: behind, inside and the ear canal
• Chest and upper back: ring- or petal-shaped patches

The cause

Malassezia, skin oil and an overactive reaction

Malassezia yeasts live on everyone's skin and feed on skin oil. In people prone to seborrhoeic dermatitis, the skin mounts an inflammatory response to them: enzymes from the yeast break skin oil down into irritating fatty acids, which disturb the skin barrier and drive redness and scaling. That is why the rash sits where oil glands are densest, and why antifungal treatments help even though this is not an infection in the usual sense.

Individual susceptibility matters as much as the yeast. Oily skin, a family tendency, immune changes and some neurological conditions all play a part. Researchers now see dandruff and seborrhoeic dermatitis as one spectrum of the same condition, with dandruff at the mild, non-inflamed end.

Triggers

Why it flares: stress, sleep and weather

Stress is the most consistently documented trigger. In a French study that compared people during flares with themselves in remission, a higher level of stress in the previous month was linked with about four and a half times the odds of a flare. Compared with other patients, regular alcohol use and a history of smoking were also linked with flares. Lack of sleep and illness are common triggers too.

Weather is less straightforward than many people think. Studies from temperate countries link seborrhoeic dermatitis with cold, dry months: in an Istanbul clinic study of 5,316 patients, it was diagnosed most often from November to February and least in June and July, and was inversely linked with temperature and with maximum humidity. Singapore has no winter, but long days in dry air-conditioning, sweat and oil left on the skin, and stress can still set it off. Triggers vary from person to person, so a simple diary of flares is worth keeping.

Look-alikes

Dandruff, rosacea, perioral dermatitis or seborrhoeic dermatitis?

These conditions can overlap, and seborrhoeic dermatitis can sit alongside rosacea. The difference matters because a steroid cream that settles seborrhoeic dermatitis for a few days can trigger perioral dermatitis or a rosacea-like rash if it is used on the face for long, so a diagnosis should come before any cream stronger than an antifungal.

Treatment

Antifungal shampoos and creams: what doctors use

For the scalp, a medicated shampoo is the first step. Useful ingredients include ketoconazole, ciclopirox, selenium sulfide, zinc pyrithione, coal tar and salicylic acid. Lather it into the scalp and leave it on for about five minutes before rinsing, two or three times a week until it settles, then about once a week to stop it coming back. Some are sold in pharmacies; stronger preparations and steroid scalp lotions need a doctor.

For the face, ears and chest, doctors usually start with an antifungal cream such as ketoconazole or ciclopirox once a day for two to four weeks, with a gentle non-soap cleanser. A mild steroid such as hydrocortisone may be used for a week or two to calm a flare, and calcineurin inhibitor creams (pimecrolimus or tacrolimus) are a steroid-free option for the face. Oral itraconazole, light therapy or low-dose isotretinoin are kept for severe or resistant cases.

The evidence is reasonable but short-term. A Cochrane review of 51 trials with 9,052 participants found topical ketoconazole 2% lowered the risk of failed clearance by 31 per cent compared with placebo at four weeks, worked about as well as steroids with 44 per cent fewer side effects, and that ciclopirox also beat placebo. A second Cochrane review found topical steroids effective in the short term, with calcineurin inhibitors similar, but most trials lasted four weeks or less.

Everyday care

Daily habits that help keep it calm

• Wash the face once or twice a day with a gentle, non-soap cleanser and lukewarm water.
• Keep using a medicated shampoo on a maintenance schedule even when the scalp looks clear.
• Do not scratch or pick off flakes; it breaks the skin and prolongs the flare.
• Choose a light, fragrance-free moisturiser; for some people, rich creams and facial oils make flaking harder to control.
• Skip scrubs, peels and strong acids while the skin is red; they strip the barrier.
• Use a daily broad-spectrum sunscreen in a light texture.
• Protect your sleep, manage stress where you can, and note what was happening before each flare.
• Do not use a steroid cream on the face for more than a week or two unless a doctor is supervising it.

See a doctor

When to see a GP or dermatologist

Mild dandruff and occasional flaking can often be managed with a pharmacy shampoo. See a GP, a dermatologist or Dr Sin Yong at IN Eternity Clinic if any of the following apply.

• Flaking has not improved after about four weeks of a medicated shampoo or antifungal cream.
• Patches are thick, crusted, weeping, painful or spreading beyond the usual areas.
• Your eyelids are red, sore or crusty, or your eyes are irritated.
• There is hair loss in patches, or shiny or scarred areas on the scalp.
• It started suddenly and severely as an adult, or you have other health problems.
• You are not sure whether it is seborrhoeic dermatitis, psoriasis, rosacea, an allergy or a fungal infection.
• You have been relying on a steroid cream on your face for weeks to keep it under control.
• A baby's rash spreads beyond the scalp, looks infected, or the baby seems unwell.

Where to go

What SkinRev Lab and IN Eternity Clinic can and cannot do

SkinRev Lab, at CityLink Mall #B1-28 by City Hall MRT, is a non-invasive aesthetic centre. It does not diagnose, treat or prescribe for seborrhoeic dermatitis. Its scalp-care session, a needle-free c-PDRN treatment in the Korea Professional (Scalp) tier, 90 minutes, S$348 before GST, is for the comfort of an oily or mildly irritated scalp, not a treatment for this condition. Persistent flaking, itching or redness should be seen by a doctor first, and our team will tell you so.

Once a doctor has the face under control, and if they agree, a gentle facial without heat, steam or acids, such as SKINLDM (about 30 minutes, S$288 per session before GST, first session S$68), can make reactive skin feel more comfortable. It does not treat seborrhoeic dermatitis, and medicated shampoos and creams should continue alongside it.

For diagnosis and prescription treatment, Dr Sin Yong sees patients at IN Eternity Clinic, 9 Scotts Road, #12-01 Pacific Plaza, beside Orchard MRT, Monday to Saturday, 11am to 8pm; medical care is priced at consultation (WhatsApp +65 8815 3008). You can equally see your own GP or a dermatologist.

Sources

References & sources

1. Clark GW, Pope SM, Jaboori KA. Diagnosis and treatment of seborrheic dermatitis. Am Fam Physician. 2015;91(3):185-190.
2. Borda LJ, Wikramanayake TC. Seborrheic dermatitis and dandruff: a comprehensive review. J Clin Investig Dermatol. 2015;3(2).
3. Okokon EO, Verbeek JH, Ruotsalainen JH, Ojo OA, Bakhoya VN. Topical antifungals for seborrhoeic dermatitis. Cochrane Database Syst Rev. 2015;(5):CD008138.
4. Kastarinen H, Oksanen T, Okokon EO, et al. Topical anti-inflammatory agents for seborrhoeic dermatitis of the face or scalp. Cochrane Database Syst Rev. 2014;(5):CD009446.
5. Lancar R, Missy P, Dupuy A, et al. Risk factors for seborrhoeic dermatitis flares: case-control and case-crossover study. Acta Derm Venereol. 2020;100(17):adv00292.
6. Akbulut TO, Suslu H, Atci T. Is the frequency of seborrheic dermatitis related to climate parameters? Sisli Etfal Hastan Tip Bul. 2022;56(1):91-95.
7. Bholah NG, Oakley A, Gomez J. Seborrhoeic dermatitis. DermNet (dermnetnz.org).

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