Leprosy mailing list – June 3rd, 2005

Ccn:     all.

Ref.:     Erythema nodosum versus erythema nodosum leprosum.

From:   T H Rea, Los Angeles, CA, USA.

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Dear Salvatore,

    I think that Ganapati and Pai (LML May 21^st, 2005) were in error to state the erythema nodosum leprosum was an example of the syndrome of erythema nodosum.  The attachment is submitted to you for consideration of dissemination on the LML.

Thank you for your attention to my request.

T. H. Rea

 

 

 

In their article, REACTIONS AND THEIR MANAGEMENT (Part 1), Ganapati and Pai make the following statement:  ENL is an example of the “Syndrome of Erythema Nodosum” which is a toxic or allergic skin reaction to a variety of infective agents and drugs.

 

The authors are correct in stating that ordinary erythema nodosum (EN) is considered to be a reaction pattern to a variety of infective agents and drugs.  EN and erythema nodosum leprosum (ENL) do have some clinical features in common, which led to the descriptive term of ENL.  However substantial evidence indicates that ENL should be considered to be distinctive entity, and not EN occurring in patients who have leprosy.  Some of the reasons supporting this view are listed.

 

1.     EN patients are predominately women, ENL patients are predominately men.  Women with LL or BL leprosy appear to be no more predisposed to develop ENL that do men with LL or BL leprosy.

 

2.      Histologically EN is a septal panniculitis, but ENL is a lobular panniculitis.

 

3.      Histologically EN is similar in all patients, whatever the underlying cause.  Also, a diagnosis of the condition causing EN cannot be made from a biopsy of the EN lesion.  In contrast, the biopsy of an ENL lesion usually has demonstrable AFB as well as foamy macrophages, suggesting a diagnosis of leprosy.

 

4.     EN is primarily a panniculitis.  In addition to panniculitis, ENL may manifest as iritis, adenitis, orchitis/epididymitis, or neuritis, structures rarely, if ever, involved in EN.

 

5.      In tuberculosis or coccidioidomycosis EN occurs in the setting of a primary infection, but ENL occurs in the setting of widely disseminated disease.