Pustular Psoriasis – Causes, symptoms and treatment

Pustular psoriasis is a skin condition that is characterised by the appearance of white, pus-filled blisters surrounded by red, tender skin.

This article outlines its causes and symptoms and explains the ways in which you can reduce its appearance on your body.

Psoriasis is a skin condition that affects between 2-3% of the UK population, or approximately 1.8 million people. Derived from the Greek word ‘psora’, meaning itch, Psoriasis is an autoimmune disease: it causes the body to attack its own cells. This accelerates the natural growth cycle of the body’s skin cells, leading to a rapid build-up of cells that causes scaling on the surface of the skin.

Pustular psoriasis is a rare, severe form of psoriasis which causes white pustules that are surrounded by, or appear on top of, red skin to appear on the body. As with all forms of psoriasis, the pustules that form on the skin are not contagious, but those who suffer from pustular psoriasis are more prone to infections than those without it. These pustules erupt easily and can be very itchy and painful.

There are two major forms of pustular psoriasis:

1. Localised pustular psoriasis
Palmoplantar pustulosis (PPP)
Acropustulosis (ACH)
2. Generalised pustular psoriasis
Von Zumbusch psoriasis

Generalised pustular psoriasis is a particularly rare form of pustular psoriasis, which can, in the most extreme cases, become life-threatening if not given the proper treatment. Pustular psoriasis affects men and women at equal rates, but affects boys at a higher rate than girls. The average age of people who suffer from this condition is 50 years. Plaque psoriasis and guttate psoriasis are far more common forms of psoriasis, accounting for well over 90% of cases.

Each of the different variants of pustular psoriasis present a variety of symptoms.

Palmoplantar pustulosis (PPP)
Palmoplantar pustulosis is the most common of the three archetypal forms of pustular psoriasis. It is a chronic disease that affects the palms of the hands and the soles of the feet, and it is characterised by the formation of clusters of pinhead-sized, sterile pustules:

• Blisters form on small areas of your body, usually on the palms and soles
• These pus-filled spots can turn brown, peel off and crust over, which can lead to cracked skin

Acropustulosis, also known as acrodermatitis continua of Hallopeau (ACH), dermatitis repens and acrodermatitis perstans, is believed by many scientists to be a variant of palmoplantar pustulosis. This type of pustular psoriasis is very uncommon.

• It is marked by the appearance of small, painful lesions appearing on the fingertips and toes
• The pain that this condition causes can make it difficult to use your fingers and toes, and can, in the worst cases, lead to nail and bone damage

Von Zumbusch psoriasis

Von Zumbusch pustular psoriasis is the most severe form of psoriasis: its breakouts are sudden, and can result in a wide area of the body being covered with red, painful skin blotches within a matter of days. White, pus-filled blisters, or pustules, appear shortly thereafter.

• The skin tends to feel very itchy
• Sufferers often feel tired and feverish
• Dehydration, nausea and fatigue are common

This is a rare, serious disease which can lead to hair and nail loss, secondary bacterial infection and liver damage. You should book an appointment to see your doctor immediately if you are concerned that you are suffering from its symptoms.

Each of the different types of pustular psoriasis are caused by a combination of genetic and environmental factors.

Palmoplantar pustulosis (PPP)

Researchers have identified several risk factors that may contribute to a person developing palmoplantar pustulosis:

• Smoking, or a history of smoking
Studies have shown that up to 90% of people with this condition smoked, or used to smoke
• Family history of palmoplantar pustulosis or psoriasis
• The presence of other autoimmune disorders

Common causes of flare-ups are similar to those for guttate psoriasis, and include:

• Smoking
• Infections, particularly strep throat
• Stress
• Some medications, e.g. steroids

Scientists believe that this condition has a genetic basis, too: mutations in certain genes (IL36RN, CARD14, and AP1S3) are associated with both PPP and ACH, which is discussed below.

Palmoplantar pustulosis is more common among women than it is among men, and it is rare in children.

Acropustulosis (ACH)
The causes of Acropustulosis, or ACH, are not fully understood. In the majority of cases, however, sufferers experienced a minor trauma or infection prior to developing its symptoms. In recent years, several studies have suggested genetic causes of ACH.

ACH usually appears in infants, but it can also affect adults. It often develops after a child has suffered from scabies.

Von Zumbusch psoriasis

Von Zumbusch can develop at any age but predominantly affects adults over the age of 50, and almost always requires treatment in a hospital.

With Von Zumbusch, there are certain specific triggers that can lead to flare-ups:

• Emotional stress
• The sudden discontinuation of corticosteroid drugs
• Medications, including salicylates, lithium, and penicillin
• Excessive sun exposure
• Phototherapy

Pustular psoriasis is the most serious and potentially debilitating form of psoriasis. If you are concerned that you may be suffering from this skin condition, book an appointment to see your doctor or dermatologist immediately.

Topical Therapy for Psoriasis
There is no cure for pustular psoriasis, but a range of treatments exist which can improve the symptoms and appearance of psoriatic skin patches.
The most common topical therapies for pustular psoriasis are creams and lotions containing  corticosteroids or  keratolytic agents. Moisturising products and emollients are used as adjunctive care and are beneficial during the remission and flare-up phase of Psoriasis. 

UreaRepair PLUS 10% Urea Lotion and UreaRepair Plus 5% Urea Replenishing Body Wash are both suitable for the treatment of pustular psoriasis, and can provide effective relief for the symptoms of this skin condition.

Topical treatments and keratolytic agents are essential for the treatment of psoriasis. They support the efficacy of any systemic drug therapy. During the initial keratotic phase (the name given to the phase when psoriatic plaques start to form), Keratolytic agents are most beneficial due to their exfoliating properties. They help to reduce the scales of psoriatic plaques, as they exfoliate excessive skin. These agents can be used in conjunction with moisturisers and emollients. 

Topical corticosteroids are effective at all times, but they should not be used continuously for long periods, so doctors often reserve them for flare-up phases. Topical corticosteroids have anti-inflammatory properties, reducing both the rate at which the patches form and the irritation that comes with them. Moderate strength topical corticosteroids are often used for psoriasis on the face, genitals or areas that require stretching or flexing. They are often used in combination with emollients and moisturisers.