A man notices flaking in his eyebrows and redness beside his nose. He concludes his skin is dry, buys a moisturiser, and gets a partial and temporary improvement. Six months later he is still doing it. The condition he has is not dryness, and the treatment for it is not moisturiser.
1. What it is
Seborrhoeic dermatitis is an inflammatory condition occurring where sebaceous glands are dense. The current understanding is that it represents an inflammatory response to Malassezia, a lipid dependent yeast that lives on normal skin. The yeast is not an infection acquired from anywhere; it is a normal resident. What varies between people is the immune and inflammatory response to it, and the amount of lipid available.
That explains the distribution: scalp, eyebrows, the folds beside the nose, behind and inside the ears, the beard area and sometimes the mid chest. It also explains why it is more common in men, whose sebum output is higher and stays higher. Dandruff is the same process, confined to the scalp and without much visible inflammation.
2. What it looks like
Fine to coarse scale, often slightly greasy and yellowish rather than dry and white. Underlying redness, particularly in the nasolabial folds, the glabella and along the cheek line of a beard. Itch, which is variable. In darker skin the redness may read as a subtle change in tone or a violaceous hue, and hypopigmented patches can be a prominent feature, which is one of the ways the diagnosis gets missed.
It fluctuates. Cold weather, stress, illness and alcohol are commonly reported aggravators. It is markedly more common and more severe in people with Parkinson's disease and in people with significant immunosuppression, which is why unusually severe or abruptly extensive disease is worth mentioning to a clinician.
3. What treats it
UK primary care guidance is consistent and the agents are widely available.
| Site | First line | How it is used |
|---|---|---|
| Scalp | Medicated shampoo containing an antifungal such as ketoconazole, or zinc pyrithione, selenium sulphide or coal tar | Left in contact for the stated time, typically several minutes, two to three times a week during a flare, then intermittently |
| Face, eyebrows, nasolabial folds | Topical antifungal cream, usually an azole | Applied regularly for two to four weeks, then as needed |
| Beard area | Antifungal shampoo used on the beard, rinsed out | As for scalp; a cream may be needed on the skin beneath |
| Inflamed flare | A short course of a mild topical corticosteroid, alongside the antifungal | Short courses only, on clinical advice; long term facial steroid use causes its own problems |
| Maintenance | Continued intermittent antifungal use | The condition relapses. Management is control, not cure |
The most common reason for treatment failure is under-use: applying a shampoo and rinsing it immediately, or stopping the moment things improve. Contact time and regular maintenance are the two variables that make the difference.
4. The beard problem
A beard creates a warm, occluded, sebum rich environment, which is close to ideal for this condition. Men who grow beards, particularly those who did so to escape shaving problems, frequently develop flaking and itch within weeks and interpret it as beard dryness.
Beard oil is a cosmetic conditioner. It coats the shaft, improves feel and does nothing to the inflammatory process, and in some men the added lipid makes matters worse. The correct approach is an antifungal shampoo used on the beard with adequate contact time, and an emollient on the skin beneath only if it is genuinely dry. This is set out further in beards and the skin underneath.
5. What it gets confused with
- Dry skin. Distribution is the tell: dryness does not favour the nasolabial folds and eyebrows specifically.
- Rosacea. Both cause central facial redness, and they frequently coexist. Rosacea has flushing, papules and pustules without comedones, and lacks greasy scale. See rosacea in men.
- Psoriasis. Scalp psoriasis produces thicker, more adherent, silvery scale with a sharper edge, and there are usually clues elsewhere on the body.
- Contact dermatitis. Follows the pattern of contact with a product, often around the hairline or where a fragrance was applied.
- Tinea. Fungal infection of the beard area exists, is uncommon, and looks different, with an expanding edge.
6. The scalp, which is where most men start
Persistent scalp itch with flaking is the commonest presentation and often the least treated, partly because dandruff is coded as cosmetic. Two points are worth making. First, an anti-dandruff shampoo used correctly, with contact time, several times weekly, is genuinely effective for most people, and a rotation between different active ingredients is often more effective than persisting with one. Second, a scalp that is red, sore, weeping, or losing hair in patches is not dandruff and should be seen.
7. What else helps, and what does not
Reasonable adjuncts include reducing very hot water on the scalp and face, avoiding heavily occlusive styling products, and recognising personal triggers such as stress and alcohol. Sun exposure is often reported to improve the condition, which is true and is not a reason to seek ultraviolet exposure given what it does over a lifetime, discussed in photoageing in men.
What does not help: scrubbing the scalp, using stronger surfactants, applying oils to the face, or switching brand repeatedly without ever giving an antifungal enough contact time to work.
8. What to expect over time
This is a chronic relapsing condition, and framing it as such at the outset prevents a great deal of frustration. It is not cured, it is controlled, and the pattern most men experience is periods of quiescence punctuated by flares that follow stress, illness, cold weather or a lapse in maintenance treatment.
A reasonable expectation is clearance of a flare within two to four weeks of consistent antifungal use, followed by intermittent maintenance to keep it there. Men who treat only during flares and stop entirely between them tend to flare more often, which is the commonest reason the condition is described as untreatable.
Two situations warrant a lower threshold for assessment. Sudden onset of severe or unusually extensive disease is worth mentioning to a GP, since marked seborrhoeic dermatitis is associated with certain underlying conditions. And where the scalp is genuinely sore, weeping or losing hair in patches, the diagnosis is in question and a look is warranted rather than another shampoo.