Represents a form of panniculitis, or inflammation of the subcutaneous fat, which manifests as tender, raised, erythematous nodules predominantly affecting the shin area

Aetiology

• NO cause (idiopathic) - 50%
• Drugs, particularly sulfonamides and dapsone
• Oral contraceptive pill (OCP)
• Sarcoidosis
• Ulcerative colitis and Crohn's disease
• Microorganisms: tuberculosis, streptococcus, toxoplasmosis

Clinical features

• Tender, raised, red or violet nodules, usually located on the anterior surface of the legs
• Accompanied by systemic symptoms such as fever, malaise, and arthralgia in some cases

Investigations

• Clinical diagnosis
• Investigations to rule out underlying causes include: FBC, inflammatory markers, CXR, tests for IBD

Management

• Treat underlying cause
• Other treatment strategies:
  • NSAIDs to alleviate pain and inflammation
  • Rest and leg elevation
  • Potassium iodide or colchicine may be used in severe cases
  • Corticosteroids are used sparingly and typically reserved for severe, refractory cases