Sweet Syndrome

#med #disease

AKA Acute Febrile Neutrophilic Dermatosis

Presentation :

Fever is almost always present
- Almost all drug-induced cases will have fever
- ~80% of maligant and classical cases will have fever
Rash: typically abrupt onset, erythematous/violaceous, tender/burning, edematous, and inflamed papules/plaques (significant dermal edema causes raised lesions; may also lead to pseudovesicular or pustular appearance). May have a targetoid appearance in some cases.
- Upper extremities are most commonly involved, but can be widely distributed on trunk, lower extremities, head, and neck
Extracutaneous symptoms:
- Constitutional sx: arthralgia, myalgia, fatigue, malaise, and headache
- Occular manifestations: inflammation, especially conjunctivitis but also episcleritis, scleritis, keratitis
- Many other uncommon manifestations in other organs
Three major categories of presentations:
- Classical (majority of cases): associated with IBD, pregnancy, infections (URIs, GI infxns, and others; usually 1-3wk later), and less commonly other autoimmune diseases
- Malignancy-associated: may precede, follow, or appear concurrently with a malignancy. More commonly hematologic (AML, MPNs), but solids as well.
  - Occurrence in pts in remission may suggest disease recurrence
- Drug-induced: Many drugs have been implicated (most commonly G-CSF). Typically appears ~2wk after first exposure and will recur on re-exposure.

Not well established. Thought to be a hypersensitivity reaction to microbial, tumor, or other antigens leading to production of cytokines which recruit neutrophils

Peripheral leukocytosis with neutrophilia is present in most patients
- Non-specific inflammatory markers (ESR/CRP) are also elevated
Two separate sets of diagnostic criteria used:
- Classical or Malignancy associated (2 major + 2/4 minor criteria):
  - Major criteria:
    - Abrupt onset of painful erythematous plaques or nodules
    - Histopathologic evidence of a dense neutrophilic infiltrate without evidence of leukocytoclastic vasculitis
  - Minor criteria:
    - Fever (>38°C)
    - Association with underlying hematologic/solid malignancy, inflammatory disease or pregnancy, OR preceded by upper respiratory infection, gastrointestinal infection, or vaccination
    - Excellent response to treatment with systemic glucocorticoids or potassium iodide
    - Abnormal laboratory values at presentation (3/4 of: ESR >20 mm/hour, elevated CRP, >8000 leukocytes, >70 percent neutrophils)
- Drug-induced (all 5 criteria):
  - Abrupt onset of tender or painful erythematous plaques or nodules
  - Dense dermal neutrophilic infiltrate without leukocytoclastic vasculitis
  - Fever (>38°C)
  - Temporal relationship between drug ingestion and clinical presentation, OR temporally related recurrence after oral challenge
  - Temporally related resolution of lesions following drug withdrawal or treatment with systemic corticosteroids