Erythema Nodosum....and a word on Sarcoid

This is a good example of Erythema Nodosum [from Nature Clinical Practice Gastroenterology and Hepatology (2008) 5, 278-281] .

Remember that EN is an immunologic response, and presents as painful nodules, classically on the extensor surfaces, more on the shins but can also be seen on the arms. They are often dark purple or red in colour. This is a panniculitis - an inflammation of the subcutaneous fat. Imagine if somebody repeatedly hit your legs with a bat.....that is how EN looks and feels.

Causes:

• Infectious: TB, Streptococcal pharyngitis, fungal infections (histoplasmosis, blastomycosis, coccidiomycosis), Leprosy, Syphilis, and gastroenteritis from bacterial sources (eg Yersinia, Campylobacter) are the more common infectious causes.


• Autoimmune: Inflammatory Bowel Disease, Behcet's disease, and Lupus.


• Malignancy: lymphoma


• Sarcoid: See below


• Pregnancy and OCPs may be associated


• Medications: sulfa drugs have been implicated.

A word on sarcoid - we touched on the two acute manifestations of this condition:

1. Lofgren's Syndrome: this represents migratory arthralgias, erythema nodosum, and hilar adenopathy, often accompanied by fevers. Here is a cool article looking at prognostic variables in disease.


2. Uveoparotid Fever: This is exactly as advertised. Patients present with 1. uveitis, 2. parotitis, and 3. fever. This is also referred to as Heerford's syndrome, or Heerfort-Waldenstrom syndrome. Here is a great review of this syndrome.