Which clinical type of psoriasis is characterized by sudden onset of tiny pustules on erythematous base, often triggered by systemic infection or drug withdrawal?

Explanation

## Types of Psoriasis: Clinical Classification ### Pustular Psoriasis (Generalized Acute Type) **Key Point:** Generalized acute pustular psoriasis (von Zumbusch type) presents with: - **Sudden onset** of innumerable tiny pustules on an erythematous base - **Systemic symptoms**: fever, malaise, arthralgia - **Common triggers**: systemic infection, abrupt withdrawal of systemic corticosteroids, pregnancy, certain drugs (lithium, beta-blockers) - **High-risk condition**: can progress to erythroderma and sepsis ### Comparison of Psoriasis Types | Type | Onset | Morphology | Trigger | Severity | |------|-------|-----------|---------|----------| | **Plaque** | Insidious | Well-demarcated plaques | Trauma, stress | Chronic, stable | | **Guttate** | Acute | Tiny (1–10 mm) droplet-like papules | URTI, streptococcal infection | Self-limited, may resolve | | **Pustular (acute)** | Sudden | Tiny pustules on erythema | Infection, drug withdrawal, pregnancy | Severe, systemic | | **Erythrodermic** | Variable | Diffuse erythema >90% BSA | Trigger in pre-existing psoriasis | Life-threatening | **High-Yield:** The **hallmark of acute pustular psoriasis** is the **sudden onset of pustules with systemic toxicity** — this is the most severe and acute form, requiring urgent hospitalization and management. **Clinical Pearl:** Unlike guttate psoriasis (which is triggered by streptococcal pharyngitis and self-limited), pustular psoriasis is triggered by **drug withdrawal** (especially corticosteroids) and can be life-threatening. This is a critical distinction in exams. **Mnemonic — SPURT:** **S**udden onset, **P**ustules, **U**rgent/systemic symptoms, **R**ecent trigger (infection/drug withdrawal), **T**oxic appearance. ### Pathophysiology The sudden shift from plaque to pustular morphology reflects acute mobilization of neutrophils into the epidermis (subcorneal and intraepidermal pustules), often triggered by removal of immunosuppressive therapy or acute systemic stress.