Makindo Medical Notes.com

Related Subjects: |Nikolsky's sign |Koebner phenomenon |Erythema Multiforme |Pyoderma gangrenosum |Erythema Nodosum |Dermatitis Herpetiformis |Lichen Planus |Acanthosis Nigricans |Acne Rosacea |Acne Vulgaris |Alopecia |Vitiligo |Urticaria |Basal Cell Carcinoma |Malignant Melanoma |Squamous Cell Carcinoma |Mycosis Fungoides (Sezary Syndrome) |Xeroderma pigmentosum |Bullous Pemphigoid |Pemphigus Vulgaris |Seborrheic Dermatitis |Pityriasis/Tinea versicolor infections |Pityriasis rosea |Scabies |Dermatomyositis |Toxic Epidermal Necrolysis |Stevens-Johnson Syndrome |Atopic Eczema/Atopic Dermatitis |Psoriasis

About

• Seborrhoeic dermatitis is managed with treatment that reduces the level of skin yeast - these include creams and shampoo, which can be used safely on a long-term basis.

Aetiology

• The Pityrosporum ovale, a normal skin organism, plays some role
• Severe disease with Parkinson's disease and HIV
• Possible genetic factors but not classically inherited

Clinical

• Dry scaly flaking rash over the eyebrows and sides of nose and ears and scalp and chest which may be itchy
• Severe disease affects external auditory canal
• May worsens in stress, cold weather

Associations

• Parkinson's disease
• Human immunodeficiency virus (HIV) infection
• Stroke - affect scalp in a unilateral distribution, corresponding to the affected hemisphere.
• The Pathophysiology of this phenomenon is not completely understood

Investigations

• The diagnosis is made by examining the rash. It is not usually necessary to take a skin sample (biopsy) or to do any blood tests, but if someone is at risk of HIV they should get tested. This is important as early treatment of HIV reduces the risk of passing it on and improves the health of the affected person.

Differential

• If there is a suspicion of ringworm of the scalp, then skin scrapings can be sent to look for tinea fungus (mycology).
• Seborrhoeic dermatitis can be difficult to distinguish from other kinds of dermatitis when certain areas such as the eyelid or genital area are affected or if it is very widespread. Severe scalp seborrhoeic dermatitis can resemble psoriasis. In psoriasis, the scales are thicker and whiter and the face is not usually affected.

Management

• Treatment is usually needed on a long-term basis, though sometimes it is possible to take a break. The choice depends on which areas of the body are affected and whether there is a lot of irritation:
• In the scalp: medicated, anti-dandruff shampoos containing agents such as zinc pyrithione, selenium sulphide or Ketoconazole can be used regularly. For best results, wash into the scalp, then wait 5-10 minutes before rinsing. Thick scales can be removed before shampooing by applying a descaling preparation containing coconut oil and salicylic acid for several hours or overnight. This can be messy, but it usually works well. If irritation is troublesome, your doctor may prescribe a steroid scalp lotion, gel or shampoo for occasional use.
• Elsewhere: anti-yeast creams or ointments are usually effective and can be used safely as a long-term treatment. Examples include clotrimazole, miconazole and nystatin. They are sometimes combined with a mild steroid for a few weeks to settle inflammation.
• Washing your body with an antifungal shampoo containing Ketoconazole may also help. Leave the shampoo on for 5 to 10 minutes before rinsing it off.
• In the ear canals: medicated eardrops may help. Do not clean the ears with cotton buds as this causes more irritation.
• On the eyelids: carefully cleaning between the lashes with an eyelid cleanser or baby (non-sting) shampoo helps to lift skin flakes and reduce inflammation. Occasionally, if the rash is widespread or resistant to the treatments listed above, your doctor may suggest a short course of oral anti-yeast medication.
• Once your scalp is clear, continue using an anti-fungal shampoo once a week to reduce the chance of the rash coming back. A plain moisturiser may help to reduce the scaling and redness of the skin. Changing your diet is not likely to make any difference.