SEBORRHOEIC DERMATITIS

Seborrhoeic Dermatitis (SD) consists of an inflammation of the skin that often appears on the seborrhoeic areas of the skin (areas that produce more sebum).

It is a chronic/relapsing condition with no definitive treatment.

Causes

There are a combination of factors that produce SD, although the ultimate factors are not well understood.

Most of normal skin contains some yeast as part of the “flora”. For some unknown reasons, people suffering from SD have an increased number of yeast on the skin where most of the sebaceous glands are located (around nose, scalp, behind and inside ears, chest, and even armpits and groins). By using anti-fungal preparations the SD often gets better. However, it also gets better with anti-inflammatory creams or lotions, such as steroids or even some other preparations against psoriasis. People with bad SD may also display symptoms of psoriasis, as these two entities are somehow connected.

SD is not contagious and it is likely to have a genetic component, being rather frequent that patients with SD have some other members of the family affected.

It is not known to be related to any type of diet.

Any form of psychological or physical stress (accident, operation, etc) may trigger a flare up.

It normally affects patients that are otherwise healthy, however very aggressive forms of SD may appear in individuals affected by neurological conditions such as Parkinson’s disease and also in immunosuppressed patients (i.e., patients with HIV infection)

Symptoms and signs

It affects most commonly the sides of the nose, the eyebrows, the scalp, the hairline, and the ears.

Also chest, back, armpits, groins and other creases may be affected.

On the head, the rash appears as a reddish area on top of which some yellowish greasy- looking scales appear. It may be sore and/or itchy. On the scalp it can range from subtle dandruff to thickened scaly plaques. On the face, the inner aspects of the eyebrows and the sides of the nose may be affected. The ears may become quite inflamed not only on the back of them but also inside the ear canal. Ears may become superinfected by bacteria. The eyelids may also be red and irritable (blepharitis). On the chest and the rest of the body the lesions are often reddish plaques with scales that produce itching.

Diagnosis

The diagnosis is only based on clinical examination. In very rare occasions, the dermatologist may need to perform a biopsy to exclude other conditions.

Sometimes it may be difficult to differentiate between SD and Psoriasis, particularly when affecting the scalp. As already stated, both conditions may be present at the same time.

It may be necessary to perform a skin scraping to exclude other fungal infections like scalp ringworm if the doctor suspects it.

Prognosis

Unfortunately SD cannot be cured completely, but with the appropriate treatment may get under control. It usually waxes and wanes for most of the patient’s life.

Treatment

Most of the treatments, when used for a while, help to keep the condition under control. There are cases where a rotational therapy is necessary when a certain previous treatment has stopped from being effective.

Maintenance treatment is often recommended to prevent from having further relapses:

• Scalp: It may be needed a combination of products.
• Medicated Shampoos containing Tar derivates, Zinc pyrithione, Selenium, anti-fungal preparations (ketoconazole, etc.) are usually recommended as maintenance treatments. The foam has to be left on the scalp for at least 5 minutes.
• Steroid lotions/creams/foams to reduce the inflammation. They should not be used on a very regularly basis, as they can cause side-effects.
• Salicylic Acid-based preparations and other products to reduce the amount of scales in the area.

• Face:
• A mild steroid cream may be used for a few days on the affected areas.
• Some special moisturisers may help to reduce the sebum production and therefore may help the condition.
• Some anti-fungal creams or lotions can be used on a more regular basis than the steroids. However, these preparations are often not as effective as steroids.
• Inside the ears some eardrops may be needed since applying creams in that area is difficult.

• Rest of the body:
• On the chest and on other areas of the back, a medium potency steroid may help.
• On the creases, steroid creams may produce important side-effects, therefore they should be used very carefully.
• Other preparations against psoriasis as the Vit D derivates may help as well.
• Medicated body gel with Ketoconazol, sulphur, etc may also help improving body lesions.

In some resistant cases a course of light treatment may be required.

 

Should you have any further doubts, do not hesitate to discuss them with your Dermatologist.