What Is Generalized Pustular Psoriasis?

Pustules that appear in a wave-like fashion on psoriatic or normal skin are the most common sign of generalized pustular psoriasis. These pinhead-sized, sterile pustules are often found at the borders of growing, severely inflammatory plaques or over inflamed skin. The type and severity of GPP signs and symptoms vary among afflicted individuals.

Common signs and symptoms of GPP include:

• Reddish discoloration of the skin
• Pus-filled blisters (pustules) over the body
• Fever and chills
• Headache
• Rapid heartbeat
• Nausea and loss of appetite
• Muscle weakness
• Furrowed tongue
• Nail abnormalities

Initially, red and painful areas of skin may be seen. Within a few hours, 1- to 2-mm pustules appear. After a day or so, the pustules consolidate to create blisters that dry up and peel away, leaving a glazed, smooth appearance to the skin.

In many cases, the exact cause of generalized pustular psoriasis is unknown. GPP often occurs in people who already have psoriasis. However, many cases of GPP occur even without a history of psoriasis.

Common causes of GPP include:

• Genetic mutations:
  • Mutations in the IL-36RN gene
  • Mutations in the CARD14 gene
  • Mutations in AP1S3 genes
• Use or withdrawal of certain drugs:
  • Lithium
  • Methotrexate
  • Corticosteroids
  • Aspirin
  • Salicylates
  • Progesterone
  • Psoriasis medications 
  • Some beta-blockers
  • Iodide-containing medicines
  • Nonsteroidal anti-inflammatory drugs, such as indomethacin
• Infections:
  • Dental infections
  • Upper respiratory tract infections

Risk factors for GPP include:

• History of or existing psoriasis
• Pregnancy
• Sunburn
• Irritation from topical coal tar and anthralin therapy
• Age (GPP can present at any age but is rarer in young children)

Research on dermatology has proposed a classification for two conditions that include:

• Pso+:
  • Represents patients with a personal history of psoriasis
  • The most common precipitating factor is corticosteroid withdrawal
• Pso-:
  • Represents patients with no history of psoriasis
  • The most common precipitating factor is infection

A triggering factor causes the illness in the vast majority of cases.

Treatment for generalized pustular psoriasis varies widely, and several different medications have been shown to be effective. The goal of treatment is to:

• Reduce fluid loss
• Restore electrolyte balance
• Limit secondary infections.

GPP may even require hospitalization in severe cases or when there are systemic complications such as electrolyte imbalances.

Treatment options for GPP include:

• Application of low-potency corticosteroids
• Immunosuppressant drugs
• Oral retinoid medications
• Antibiotics
• Tumor necrosis factor blockers
• Interleukin or interleukin receptor antagonists
• Colchicine
• Chemotherapeutic agents 
• Phototherapy, which uses ultraviolet B light to treat affected areas of skin
• Regular medical screening 

Treatment methods are determined by the extent of body surface area affected:

• Topical therapy with steroid creams or ointments are usually sufficient for limited skin involvement.
• Systemic treatment, which can include either oral medicine or injectable biologic therapies, is usually necessary for more extensive illness.
• Treatment of more severe GPP may involve electrolyte monitoring, which is why hospitalization is required.
• Many of the most effective GPP therapies are fast-acting, such as cyclosporine or infliximab.
• Interestingly, some patients with GPP have a mutation in a protein called interleukin-36; future treatments for these individuals may include more focused medications targeting interleukin-36-related biological pathways.
• Experts advise individuals with GPP to contact a dermatologist as soon as possible. A multi-pronged strategy is often required to restore quality of life.

If a person already has psoriasis and develops early signs and symptoms of GPP, receiving quick medical assistance may help stop the illness from progressing.

Similarly, patients who are taking medications that have the potential to cause GPP may benefit from learning how to detect triggers so that they can detect the signs as soon as possible.

Proper nutrition, fluid intake, and timely treatment of infections with antibiotics is recommended.

Complications of GPP may include:

• Anemia
• Electrolyte imbalance 
• Malabsorption of nutrients and drugs
• Kidney and liver malfunction
• Secondary bacterial infections
• Erythroderma (reddening of skin) following remission
• Relapse
• Dehydration
• Hypoalbuminemia
• Septicemia

In addition to general care of complications, specific therapy may include systemic steroids, methotrexate, oral retinoids, or cyclosporin-A.

Severity of symptoms and any related problems determine the prognosis of GPP. Remission occurs in most cases within a few days or weeks. However, the disease may recur. 

GPP can be fatal, and hospitalization is usually required to save the patient.