Seborrhoeic Dermatitis: Causes and Treatments
Seborrhoeic dermatitis means itchy red, flaky skin affecting greasy or oily skin zones, often on the face, being close to the scalp line or even in the centre of the chest.
Seborrhoeic dermatitis is very common, but many people are not aware that they have it. At least 4% of patients suffer at some time from seborrhoeic dermatitis and dandruff. Dandruff is just a very mild seborrhoeic dermatitis of the scalp. Dandruff affects almost half of all adults. Seborrhoeic dermatitis is more common in men who have greasier skin than women anyway.
Seborrhoeic dermatitis is probably trigged by the yeast called Malassezia that lives on the skin or occurs because of an overreaction to this yeast by the natural immune system of the body. Please note that this yeast is not the same as that which causes thrush, nor the same as yeast found in food. Seborrhoeic dermatitis is regarded as benign, and this is because it is not linked to any underlying illness and it can be treated. It is not hereditary either.
The main problem that patients experience from seborrhoeic dermatitis is that it can be quite severe and stubborn particularly in patients who have HIV infection and people who have Parkinson’s disease. For patients who always feel tired and stressed, that can trigger flare up of seborrhoeic dermatitis. It is also more common in the cold than in the warm weather. Surprisingly it is not related to diet as far as physicians are aware.
Seborrhoeic dermatitis management is aimed at reducing the level of skin yeast by use of special creams and shampoos. These can be used quite safely on a long-term basis.
The symptoms of seborrhoeic dermatitis vary in each person. The affected areas are usually itchy, sore, a little sensitive with a little bit of flaking skin that can be bothersome and particularly embarrassing, especially if it falls onto their clothing. Some people will have a rash associated with it, so there will be some redness. The affected areas are a little red with rather greasy looking skin flakes. It appears unpleasant. It does not make people look attractive to other people, and that increases their embarrassment.
In particular, seborrhoeic dermatitis can be visible on the scalp and mainly affecting the inner eyebrows and creases around the nose and cheeks. Even the eyelids can become red, swollen and flaky; then it is called seborrhoeic blepharitis.
Seborrhoeic dermatitis can affect the area around the ears, just inside the ear canal or behind the ears. The ear canal can get infected and then it is called an otitis externa, which in turn can cause blockage of the ear and trouble hearing.
Seborrhoeic dermatitis can also occur on chests or between the shoulder blades where it appears more as well defined round pinky-red patches with some mild scaling. Seborrhoeic dermatitis occurs in skin folds, moist areas such as under the breasts, groin, under the arms or even the folds of skin on the abdomen, if there are excess abdominal folds. If the patient has darker than average skin, the seborrhoeic dermatitis areas appear lighter (hypopigmented) or darker (hyperpigmented) than surrounding skin that is characterised by the flakiness.
Dr Jennifer Crawley will examine your rash and decide whether it is seborrhoeic keratitis. She can decide this clinically, and it is not usually necessary to do a skin biopsy or take a specimen to see if the yeast is present or do any blood tests. However, if she thinks there is a risk that you might be in danger of HIV, then she would recommend a test.
This test is important because obviously the early detection and treatment of HIV will reduce the risk of passing that virus on to another person. Only if Dr Crawley thinks there may be ringworm of the scalp then would she do skin scrapings to look for mycology (tinea fungus).
There are other types of dermatitis that can look similar to seborrheic dermatitis. These forms affect the eyelid and genital area. Severe scalp seborrhoeic dermatitis can also resemble psoriasis. However, in psoriasis, the scales are much thicker and whiter, and the rest of the face is usually not affected. For instance, the medial end of the eyebrows or around the corners of the nose are particularly affected.
Seborrhoeic dermatitis cannot be entirely cured, but it can be treated and made very tolerable. It is absolutely possible to improve the condition; however, if you stop looking after it, it will come back.
Treatment is required on a long term basis. However, you can have breaks between treatment depending on which area is treated the following can be helpful. If your seborrhoeic dermatitis affects your scalp then using a medicated anti-dandruff shampoo containing a zinc pyrithione or selenium sulphide or Ketoconazole can be helpful when used regularly.
It is best to wash the hair and massage the shampoo into the scalp and then leave it on for 5 or 10 minutes and then rinse. The thick scales can be removed before the shampooing by using a delicate de-scaling preparation containing coconut oil or salicylic acid for several hours or overnight. Although this is messy, it does work well.
If the irritation is very troublesome, your doctor can prescribe a steroid scalp lotion gel or shampoo for occasional use. Elsewhere on the body anti-yeast creams and ointments are effective and can be used safely as a long-term treatment. Examples of these creams and ointments include Clotrimazole and Miconazole and Nystatin. These may be combined with a mild steroid as well to help settle local inflammation.
Washing your body with an antifungal shampoo containing Ketoconazole can also help, leaving the shampoo on for 5 to 10 minutes before rinsing off.
When seborrhoeic dermatitis affects the ear canals, medicated ear drops can help; however, be very careful if you plan to use cotton buds as this can cause more irritation and even injury.
If seborrhoeic dermatitis affects the eyelids, then it is called seborrhoeic blepharitis. It can then affect the eyelashes, and they need to be cleaned with an eyelid cleanser such as the Blephasol solution or Blephaclean wipes or use a baby non-stinging shampoo to help lift off the skin flakes and reduce the local inflammation.
I hope that you find this blog post about seborrhoeic dermatitis and blepharitis helpful. If you require any further information, please do not hesitate to contact us here at Clinica London. Our skin consultant Dr Jennifer Crawley will be pleased to advise, and if you have seborrhoeic blepharitis, our ophthalmologists will also be happy to help you.