Are you experiencing painful bumps with pus surrounded by red skin? You may be affected by a skin condition called pustular psoriasis. If you want to learn more, you are in the right place. This article will shed light on the physical and functional changes associated with the disease, focusing on pustule formation and skin inflammation.

What is Pustular psoriasis?

Pustular psoriasis is a rare type of psoriasis in which fluid-filled blisters called pustules are surrounded by inflamed or reddened skin. If the pustules break, it can be painful and sore. The skin is often flaky, itchy, and discoloured due to the condition. Pustular psoriasis is an autoimmune response in which the body attacks the skin by producing more white blood cells, neutrophils, and inflammatory molecules. The accumulation of dead cells leads to scales/flakes. Research suggests that pustular psoriasis affects persons assigned male at birth and persons assigned female at birth equally, and it usually appears in adults aged 40-50 years.¹ 

Pustular psoriasis is subdivided into:

1. Generalised pustular psoriasis (GPP): It is the rarest form, with symptoms spreading over a larger area. Fever, chills, nausea, dehydration, and fatigue accompany generalised pustular psoriasis. It is further subdivided into von Zumbusch subtype, Annular subtype, Impetigo herpetiformis, and Exanthematic
2. Localised pustular psoriasis (LPP): This has symptoms confined within a specific organ or area. It is subdivided into Palmoplantar psoriasis (pustules in palms and toes) and Acrodermatitis continua of Hallopeau (pustules in fingers, toes, and nail beds)

Most of the cases are caused by unknown factors, but certain risk factors trigger pustular psoriasis, such as:¹

• Reaction to medications
• Sudden withdrawal of steroids
• Pregnancy
• Skin infections
• Stress
• Vaccinations

Understanding what actually happens during the disease is necessary for efficient treatment. It can also help to develop targeted interventions that can improve the outcome and experience of affected persons. This calls for proper knowledge of the pathophysiology of pustular psoriasis, including pustule formation and skin inflammation.

How do pustules form?

Pustules are small, raised, pus-filled lesions on the skin. These are distinguishing features of pustular psoriasis, formed byseries of pathological processes. 

Abnormal immune response

Pustular psoriasis is caused by abnormal immune response. There are immune substances called pro-inflammatory cytokines, released in an imbalance during the response. This leads to activation of multiple pathways such as IL-1, IL-17, IL-23, and IL-36, resulting in an influx of cells called neutrophils.² Aggregation of these neutrophils in the outermost layer of skin is responsible for pustule formation.  

Keratinocyte malfunction 

Environmental triggers can have an impact on keratinocytes. Keratinocytes are the predominant cells found on the epidermis of the skin. These cells undergo abnormal proliferation and differentiation, which leads to the accumulation of cells that cannot shed properly. A damaged skin barrier develops with dead skin cells and neutrophils, leading to pustule formation. ³

Increased antimicrobial peptides

When there is an abnormal immune response or keratinocyte malfunction, the chances of inflammation are also high. Antimicrobial peptides (AMPs) are part of your immune system and are important to host defence against infections. When a high number of neutrophils and keratinocytes are involved, these AMPs are also produced in higher levels. Higher AMPs contribute to localised inflammation and enhance pustule formation.²

Skin inflammation- how does it occur?

Pustule formation is invariably associated with skin inflammation in pustular psoriasis. The process behind skin inflammation also involves an immune response with cytokines and other molecules. 

Inflammatory mediators

The immune cells, such as T-cells and dendritic cells, are activated, leading to a cascade of inflammatory responses. Pro-inflammatory cytokines such as IL-17, IL-23, and TNF-ɑ are released, causing more neutrophils and other cells to be recruited at the site. This leads to perpetuated skin damage.⁴

Genetic mutation

IL36RN, CARD14, and AP1S3 genes are involved in the pathophysiology of pustular psoriasis, which have significant roles in skin inflammation. IL-36RN encodes the cytokine IL-36, mutation of which causes enhanced inflammatory response leading to pustular lesions. CARD14 mutation leads to overproduction of cytokines, leading to increased skin inflammation. Dysregulation of the AP1S3 gene affects the neutrophils and keratinocytes, contributing to enhanced inflammation.⁴ 

Altered microbiome

Following the inflammatory response, the skin is prone to infection as the skin barrier is compromised. Pathogenic bacteria such as Staphylococcus aureus often proliferate in such instances, aggravating the inflammation. This can further activate the immune system, enhancing prolonged inflammatory responses.⁶

Management and treatment

Pustular psoriasis is a chronic condition that can recur, and its management is a long-term process. Though there is no cure, it can be managed with medications. Depending on the type of pustular psoriasis and its severity, healthcare providers follow different strategies for treatment. The treatment aims to clear the pustules, alleviate symptoms of pain and itching, and prevent further infection. They may include:

• Topicals — Topical retinoids and corticosteroids such as calcipotriol, tacrolimus, and triamcinolone are given in cases of localised pustular psoriasis
• Biologics — These are targeted cytokine inhibitors of IL-17, IL-21, and IL-36 such as spesolimab, brodalumab, and guselkumab. They reduce skin lesions by modulating immune responses
• Oral treatments — Oral retinoids such as acitretin, isotretinoin are often used as first-line therapies
• Phototherapy — This method uses UVA/B radiation on your skin to minimise itchiness and reduce inflammation

In some cases, an integrated therapy is done by combining one or more treatments. Novel therapeutic approaches are being explored and many drugs are in clinical trials for better treatment of pustular psoriasis. An example is the use of Tofacitinib, a first-generation Janus kinase inhibitor which has been used for the treatment of a severe GPP case.⁷

FAQs

How is pustular psoriasis diagnosed?

The healthcare provider completes a physical examination followed by the patient’s medical history. Further tests, such as blood tests and a biopsy, may also be required to confirm the diagnosis. 

Is pustular psoriasis curable?

No, there is no cure for pustular psoriasis yet. However, it can be managed by avoiding triggers and following proper medications and treatment. 

Are there any home remedies for pustular psoriasis?

You can always find online articles with home remedies. Natural substances such as aloe vera, turmeric, tea-tree oil, and apple cider vinegar are popular remedies. It is always recommended to consult with your healthcare practitioner before you try and adopt any of these.

Are there any complications associated with pustular psoriasis?

In rare GPP cases, complications such as cardiorespiratory failure, kidney and liver failure, and sepsis may occur. It can be fatal in severe cases.

What are the side effects of pustular psoriasis treatment?

Side effects of medications vary and can range from hair loss and mucosal dryness to high blood pressure and kidney problems.

Is pustular psoriasis contagious?

No, pustular psoriasis is not contagious. It does not spread from one infected person to another upon direct contact. 

How can I control the flare-up symptoms of pustular psoriasis?

Flare-up symptoms can be prevented by managing stress levels, washing skin with gentle cleansers, moisturizing often, and trying your best to avoid triggers, causing inflammation. 

Can diet and lifestyle modifications help manage pustular psoriasis?

Diet and lifestyle modifications cannot cure pustular psoriasis, but they can help reduce the severity of symptoms. Mindful eating with a diet rich in fruits, vegetables, and grains can help. Maintaining a healthy weight, minimizing smoking, and alcohol consumption also contribute to better results. 

How expensive is the treatment for pustular psoriasis?

The biologic drugs involved in the treatment of pustular psoriasis are generally expensive and range from around $10,000 to $30,000 a year.

Do I need support during my treatment?

Treatment can sometimes be long-term and exhausting in pustular psoriasis. It is always good to have someone to lean on when things are tough. Make sure to reach out to that one close friend, or someone in your family who understands what you are going through and can be there when you need them.

Summary

Pustular psoriasis is a type of psoriasis with pus-filled blisters surrounded by inflamed skin. It can be either localized or generalized, and subdivided into different types. Immune system dysregulation and risk factors trigger a series of immune responses leading to pustular psoriasis. It is a chronic condition with remission and can require long-term care. Although there is no cure for pustular psoriasis currently, it can be treated by multiple strategies including oral pills, topicals, biologics, and phototherapy. Specific treatment coupled with proper diet and lifestyle modifications can help manage pustular psoriasis and increase the quality of life.