When should I consider referring a patient with erythema nodosum to a specialist?

Consider referring a patient with erythema nodosum to a specialist if:

• There is diagnostic uncertainty requiring specialist assessment or skin biopsy.
• The erythema nodosum is severe, persistent, or not responding to initial management in primary care.
• There are systemic symptoms or signs suggestive of an underlying serious condition (e.g., infection, malignancy, or inflammatory disease) that require further investigation.
• The patient has significant impact on quality of life or complications that need specialist input.

Referral is typically to dermatology or relevant specialties depending on suspected underlying cause (e.g., rheumatology if associated with arthritis, respiratory medicine if linked to sarcoidosis or tuberculosis).