Sweet syndrome (acute febrile neutrophilic dermatosis)

Synonyms: akute febrile neutrophile Dermatose

By Dr. Pascal Bafteh · last updated 09/2026

Overview

Clinical Features & Triggers

• Triggers: Classically, infection + medications + neoplasms plus pregnancy + IBD.
• Mucosal Involvement: Sweet's Syndrome (like Behçet's disease) typically causes aphthae on the oral mucosa — from this follows the therapeutic logic Colchicine (analogous to Behçet's, inhibits neutrophil migration).
• Bullous Variant: A bullous Sweet's variant with tense blisters is typically associated with myeloproliferative disease — obligatory hematological screening.
• Associated underlying disorders: besides the para-/post-infectious forms (above all upper respiratory streptococcal infection, yersiniosis) and the paraneoplastic forms, Sweet's syndrome is associated with autoimmune diseases — first and foremost rheumatoid arthritis and inflammatory bowel disease (ulcerative colitis, Crohn's disease, often in parallel with flares); further with thyroid disease, Behçet's disease and pregnancy. Consequence: every Sweet's syndrome warrants a targeted history for joint and bowel symptoms plus haematological screening.
• Pathogenesis: Activation of neutrophilic granulocytes by dermal immune complex deposition + IL-1 + IL-17.
• Clinical Presentation: Typical are painful succulent plaques on the upper back / dorsum of hands, pseudo-vesicular appearance due to dermal edema.
• General: Typical are high fever + arthralgias plus Neutrophilia + leukocytosis.

Diagnostic Criteria (Su / Liu, Walker / Cohen)

• 2 Major + 2 Minor ⇒ Diagnosis.
• Major: Abrupt eruption + histology with dense neutrophilic infiltrate without vasculitis.
• Minor: Fever, trigger (infection / tumor / medication), excellent response to systemic corticosteroids, ESR ↑ / leukocytosis / neutrophilia.

Differential diagnoses

• Erythema nodosum
• Polyarteritis nodosa
• Abscess
• Granuloma annulare
• Urticaria
• Psoriasis vulgaris (plaque psoriasis)
• Pyoderma gangrenosum
• Leukocytoclastic vasculitis

Sources (selection)

1. Cohen 2007 Sweet syndrome

More inflammatory skin diseases

• Cheilitis granulomatosa (Miescher)
• Erythema annulare centrifugum (EAC)
• Erythema nodosum
• Graft-versus-host disease (GvHD)
• Granuloma annulare
• Cutaneous sarcoidosis
• Lichen planus
• Lichen sclerosus

Note: This page is intended for medical education and does not replace diagnosis or treatment decisions in individual cases. Treatment and follow-up content is available in the app.