Neutrophilic dermatoses

This chapter provides a brief overview of the neutrophilic dermatoses, and is set out as below. For more information refer to the related chapters.

Common features found in the neutrophilic dermatoses

• Histological features dominated by a neutrophilic vascular reaction, typically falling short of a vasculitis

• A significant proportion have a reactive or underlying systemic association - mainly haematological, gastrointestinal, rheumatological or drug-induced

• The conditions may coexist

• The neutrophilic process itself may cause systemic illness

• They may arise at the site of injury such as a needle prick, biopsy or insect bite. This reaction is known as pathergy
  

The better-known types of neutrophilic dermatoses (by no means comprehensive)

• Pyoderma gangrenosum

• Sweet's syndrome (syn. acute febrile neutrophilic dermatoses)

• Possible variants of Sweet's eg neutrophilic dermatoses of the dorsal hands

• Subcorneal pustular dermatosis

• Neutrophilic panniculitis

• Relapsing polychondritis

• Conditions overlapping with vasculitis:
• Behçet's disease
• Erythema elevatum diutinum

• Specific links with gastrointestinal disease eg pustular vasculitis/neutrophilic pustulosis (many cases represent pustular pyoderma gangrenosum), aseptic abscess in Crohn's disease, peristomal pyoderma gangrenosum

• Associated with connective tissue disease eg rheumatoid neutrophilic dermatosis

• Associated with acne eg pyogenic arthritis with pyoderma gangrenosum and acne (PAPA)

• Paraneoplastic or typically chemotherapy-associated eg paraneoplastic neutrophilic figurate erythema

• Systemic neutrophilic dermatoses eg Neuro-Sweet's syndrome, or affecting other internal organs and causing, for example, myositis, pericarditis or pulmonary complications

• Familial Mediterranean fever