Psoriatic Erythroderma

The term erythroderma describes generalised redness of the skin involving more than 80 to 90 per cent of the body surface and accompanied by scaling. When this state occurs in a patient with psoriasis, it is called psoriatic erythroderma. In ordinary plaque psoriasis, inflammation and the accelerated multiplication of epidermal cells are confined to well-defined areas. In the erythrodermic form the process becomes generalised: the whole skin turns red, warm and infiltrated and sheds scales continuously, in fine or large sheets.

What happens in the skin. In psoriasis, keratinocytes multiply far faster than normal and reach the surface before they have matured. When this involves the entire skin surface, the skin loses several functions at once: the barrier against water loss, temperature control through vasoconstriction and vasodilatation, and protection against microbes. Generalised vasodilatation directs a large volume of blood towards the skin, which can strain the heart, and the continuous loss of scales means a loss of protein.

Who is affected. This is a rare form, occurring in a small proportion of people with psoriasis, more often in adults with long-standing, extensive or unstable disease. It can also be the first manifestation of the disease, in which case diagnosis is more difficult, because erythroderma has other possible causes as well: generalised eczema, drug reactions, cutaneous lymphomas, pityriasis rubra pilaris.

Triggers frequently described:

• Abrupt withdrawal of a systemic treatment or of general corticosteroid therapy.
• Application of irritant preparations over large areas.
• Acute infections and febrile illness.
• Certain medicines, in predisposed people.
• Severe sunburn.
• Major stress and physical exhaustion.
• Excessive alcohol intake.

What the patient sees and feels. Onset may be gradual, through the spread of existing plaques, or sudden. The skin becomes intensely and uniformly red, warm to the touch and tight, and scaling is abundant and continuous. Common features include:

• Burning, tightness and itching over the whole body surface.
• Chills and a constant feeling of cold, because the body loses heat through the dilated vessels of the skin; sometimes, alternately, fever.
• Swelling, especially of the lower legs and the face.
• Diffuse hair shedding and nail changes, with nails that may detach.
• Enlarged lymph nodes, as a reaction to the extensive skin inflammation.
• Marked fatigue, loss of appetite and weight loss.

Course and complications. Psoriatic erythroderma is regarded as a dermatological emergency. Possible complications are dehydration and hydro-electrolyte imbalance, protein loss, hypothermia or, conversely, hyperthermia, bacterial superinfection of the skin with a risk of spread, and decompensation of pre-existing heart conditions through the extra circulatory load. For this reason many patients need close medical supervision, and in severe forms admission to hospital, with monitoring of temperature, hydration and blood tests.

What makes the condition worse:

• Long hot baths and rubbing the skin with sponges or rough towels.
• Perfumed or alcohol-based cosmetics applied to inflamed skin.
• Exposure to cold or to excessive heat.
• Dehydration and an insufficient intake of fluids and protein.
• Stopping or changing treatment without medical advice.

Any patient with psoriasis in whom the redness starts to become generalised, or who develops chills, fever or a deterioration in general condition, should see a doctor without delay.

In our practice, psoriatic erythroderma is addressed through the Kozak Method — internal and external treatment, individually tailored, following a consultation. Results differ from patient to patient.