Unstable Psoriasis: Clinical Entity and Management

Definition and Clinical Context

• The American Academy of Dermatology guidelines describe unstable psoriasis as acute, rapidly progressive, or severe variants of psoriasis, particularly pustular and erythrodermic forms, that represent medical emergencies requiring urgent intervention 1
• Unstable psoriasis refers to psoriasis that has become acutely severe or is rapidly deteriorating, encompassing pustular and erythrodermic forms that are medical emergencies 1

Triggers and Destabilizing Factors

• Lithium can cause severe, even life-threatening deterioration of psoriasis in patients with pre-existing disease 2
• Antimalarials, such as chloroquine and hydroxychloroquine, can severely worsen psoriasis 2
• Beta-blockers can exacerbate pre-existing psoriasis, particularly with long-term use 2
• Alcohol can precipitate or worsen psoriasis 2
• NSAIDs can worsen existing disease 2

Severity Assessment and Management

• Psoriasis can be severe irrespective of body surface area when it has serious emotional consequences, occurs in selected locations, or causes intractable pruritus 1
• The Psoriasis Area Severity Index (PASI) ranges from 0 to 72 and accounts for body surface area, redness, scaling, and plaque thickness 1