Fig 1: Eczema classification

Seborrhoeic Eczema

Pathophysiology

Overgrowth of the yeast Pityrosporum ovale induces a strong immune response in the skin of affected individuals, producing a characteristic rash in areas of skin rich in sebaceous glands.  It may be worsened by ill health, stress, fatigue and the seasons.  In children, it can also be caused by an excess of vitamin A.

Presentation

Varies according to age:

Childhood

Often presents on the scalp as yellow, greasy crusts +/-  a more generalised red, scaly rash on the trunk.

Adolescence

More common in males, affects 1-3% of the population.  Presents on the scalp (often with dandruff), along the sides of the nose, around the eyes and within the eyebrows.  The axilla, sternum, groin and glans penis may also be affected with possible blepharitis.

Adulthood/Elderly

Is commonly more severe, spreading over larger areas of the body.  Possible erythroderma.

Diagnosis

Made on the basis of history and examination following exclusion of bacterial/fungal infection and other inflammatory skin conditions

Management

Mild Steroid Ointment

1% hydrocortisone b.d.

Topical Antifungal

Miconazole

Sulphur/Salicylic Acid

In resistant cases

Tacrolimus

0.1% ointment shown to be very helpful

Ketoconazole Shampoo/ Arachis Oil

May help scalp symptoms

Soap Substitution & Emollients

Venous Eczema

Pathophysiology

This occurs on the legs as a result of prolonged venous hypertension.  The exact mechanism is not well understood but hypertension is thought to cause hyperplasia of the endothelium and extravasation of erythrocytes and lymphocytes.  These then go on to induce inflammation, redness and purpura.

Presentation

Incidence increases with age and is more common in women than men.  Brown pigmentation and scaling are seen on the lower legs, especially around the ankles.  Ulceration and/or varicose veins may also be present.

Diagnosis

Made on the basis of history and examination following exclusion of bacterial/fungal infection and other inflammatory skin conditions

Management

Emollients

Moderately Potent Topical Steroid

e.g. 0.05% clobetasone butyrate

Support Stockings

	May help to reduce venous hypertension

Compression Bandaging

Leg Elevation

Asteatotic Eczema aka “Winter Eczema”, “Eczema Craquele”, “Senile Eczema”

Pathophysiology

Unknown but thought to involve excessive use of soaps.  Age-related loss of the stratum corneum may contribute.  May follow the onset of diuretic therapy or be a presenting feature of myoedema.

Presentation

Tends to affect the elderly population, most commonly appearing on the lower legs and backs of the hands.  It tends to be worse in winter.

Management

Soap Replacement

Emollients & Bath Oils

Humidification

Mild Topical Steroids (if skin is very inflamed