What is the diagnosis and treatment for pustular psoriasis?

From the Guidelines

Pustular psoriasis should be treated with acitretin as the preferred agent, starting at 25-50mg daily, due to its efficacy in reducing inflammation and regulating keratinocyte maturation, as recommended by the joint American Academy of Dermatology-National Psoriasis Foundation guidelines of care for the management and treatment of psoriasis in pediatric patients 1.

Treatment Overview

Pustular psoriasis is a rare, severe form of psoriasis characterized by the development of sterile pustules on red, inflamed skin. The treatment approach typically involves a combination of topical and systemic therapies. For mild cases, topical corticosteroids like clobetasol 0.05% applied twice daily, combined with calcipotriene (a vitamin D analog), may be sufficient. However, for moderate to severe cases, systemic treatments are necessary.

Systemic Treatments

Systemic treatments for pustular psoriasis include:

• Acitretin, starting at 25-50mg daily, which is particularly effective for widespread guttate psoriasis, pustular psoriasis, and palmoplantar disease 1
• Cyclosporine, at a dose of 2.5-5mg/kg/day, which can be recommended for the treatment of erythrodermic, generalized pustular, and/or palmoplantar psoriasis 1
• Methotrexate, starting at 7.5mg weekly, potentially increasing to 25mg weekly
• Biologics like IL-17 inhibitors (secukinumab, ixekizumab) or IL-23 inhibitors (guselkumab, risankizumab) for severe or refractory cases

Management and Prevention

During acute flares, hospitalization may be required for fluid and electrolyte management, as pustular psoriasis can lead to life-threatening complications. Patients should avoid known triggers like certain medications (lithium, NSAIDs), infections, stress, and rapid corticosteroid withdrawal. Regular skin care with gentle, fragrance-free moisturizers helps maintain skin barrier function between flares.

Monitoring and Follow-up

Regular monitoring of patients on cyclosporine therapy is necessary to avoid chronic hypertension and kidney damage, with monthly checks of CBC, potassium, uric acid, lipids, magnesium, serum bilirubin, and liver enzymes 1. Blood pressure should be monitored regularly, and antihypertensive medications like calcium channel blockers or β-blockers may be necessary to control hypertension.

From the FDA Drug Label

There were 9 cases of pustular and 4 cases of erythrodermic psoriasis. Thirteen cases of transformation of chronic plaque psoriasis to more severe forms of psoriasis have been reported Patients generally show some improvement in the clinical manifestations of psoriasis in 2-weeks. Results of a dose-titration clinical trial with cyclosporine [MODIFIED] indicate that an improvement of psoriasis by 75% or more (based on PASI) was achieved in 51% of the patients after 8 weeks and in 79% of the patients after 16 weeks.

Pustular Psoriasis Treatment with Cyclosporine:

• The drug label reports 9 cases of pustular psoriasis in patients treated with cyclosporine.
• Cyclosporine can be used to treat psoriasis, with improvements seen in 2 weeks and significant improvement in 51% of patients after 8 weeks and 79% after 16 weeks.
• The initial dose of cyclosporine for psoriasis is 2.5 mg/kg/day, with possible increases up to 4 mg/kg/day.
• Treatment should be discontinued if satisfactory response cannot be achieved after 6 weeks at 4 mg/kg/day or the patient's maximum tolerated dose 2.

From the Research

Classification and Treatment of Pustular Psoriasis

• Pustular psoriasis has been classified into localized and generalized forms 3
• Treatment options for pustular psoriasis include acitretin, cyclosporine, methotrexate, and infliximab as first-line therapies for generalized pustular psoriasis 3
• Adalimumab, etanercept, and psoralen plus ultraviolet A are considered second-line modalities for generalized pustular psoriasis 3
• The choice of treatment should be governed by the extent of involvement and severity of disease, as well as patient-specific factors such as pregnancy or pediatric status 3

Systemic Monotherapy Treatments for Generalized Pustular Psoriasis

• A systematic review of 31 studies found that systemic retinoids, cyclosporine, biologics, and dapsone are possible first-line agents for generalized pustular psoriasis 4
• Retinoids are one of the best-supported treatment options, while biologics are an emerging therapeutic field with great potential requiring additional data 4
• The final choice of treatment should be considered within the unique context of each patient 4

Biologics in the Treatment of Pustular Psoriasis

• Biologics, including anti-IL-1β, anti-IL-1 R, anti-IL-36 R, anti-tumor necrosis factor-α, anti-IL-12/23, and anti-IL-17A, have demonstrated positive responses in patients with pustular psoriasis 5
• Anti-TNF-α is the most available biologic for the treatment of pustular psoriasis, and anti-IL-12/23 and anti-IL-17A may be considered as first- or second-line therapy for moderate-to-severe and refractory pustular psoriasis 5
• The therapeutic efficacy of biologics in pustular psoriasis may not be associated with IL-36 RN mutation status 5

Combination Therapy for Generalized Pustular Psoriasis

• Infliximab in combination with low-dose acitretin has been reported to be effective in treating generalized pustular psoriasis in two case studies 6
• This combination therapy may be considered for patients who have failed to respond to standard therapeutic options or have primary intolerance to them 6

Diagnosis and Management of Pustular Psoriasis

• Pustular psoriasis may present as a recurrent systemic illness (generalized pustular psoriasis) or as localized disease affecting the palms and/or soles (palmoplantar pustulosis) or the digits/nail beds (acrodermatitis continua of Hallopeau) 7
• Primary care providers should not hesitate to contact a dermatologist for advice and/or patient referral, as these conditions can be difficult to diagnose and may have severe consequences 7
• The role of corticosteroids in triggering and leading to flares of generalized pustular psoriasis should be noted, and physicians should avoid the use of systemic corticosteroids in the management of any form of psoriasis 7