Article discussed: Erythema elevatum diutinum a rare and poorly understood

cutaneous vasculitis: A single institution experience

Authors: Luis A. Sardiña, George Jour, Melissa P. Piliang, Wilma F. Bergfeld

Summary prepared by: Juanita Duran, MD; Pathology resident, PGY-3 (@JDuranMD)

Journal Club summary:

• EED is a rare and chronic vasculitis of unknown etiology with variable clinical presentation.
• The initiation of the disease is believed to occur via activation of cytokines, especially interleukin 8.
• Its pathogenesis remains unknown, but a leading theory postulates an immune complex-mediated vasculitis (type III hypersensitivity) as the underlying phenomenom (idiopathic or related to immune diseases).
• Reported associated causes: infections (viral and bacterial), rheumatologic diseases, and hematologic neoplasms.
• Typically presents as persistent red, raised nodules, and plaques distributed symmetrically on acral surfaces.
• Mostly involves extensor surfaces of the extremities as a spectrum of lesions.
• Classic histologic features (although non-specific) are those of leukocytoclastic vasculitis involving the papillary and mid-dermal vessels.
• Aging and more chronic lesions demonstrate onion skin-like fibrosis surrounding the vessels.
• Differential diagnoses: leukocytoclastic vasculitis, granuloma faciale, and Sweet syndrome.

Methods:

• Retrospective analysis of five cases of EED from a single institution retrieved over a period of 27 years (1989-2016).
• Criteria applied for inclusion/diagnosis:
• Lack of papillary dermal edema and microabscesses with negative direct immunofluorescence (DIF) for Immunoglobulin A deposits arguing against dermatitis herpetiformis.
• Chronic presentation, and lack of fever arguing against an acute Sweet’s neutrophilic dermatosis.
• Lack of small vessel deposits as well as a negative serological workup ruling out etiologies, such as mixed cryoglobulinemia and paraproteinemia.
• Negative direct immunofluorescence except for positive granular vascular deposits of Immunoglobulin M and/or C3.

Salient histopathologic findings are depicted in the image below:

Discussion:

• EED is an uncommon but treatable skin condition
• Various clinical and histologic mimickers exist, histologic ddx includes: bacillary angiomatosis, dermatofibroma, Sweet syndrome, pyoderma gangrenosum, granuloma annulare, granuloma faciale and Kaposi sarcoma.
• Often associated with HIV, Hepatitis B, E.coli and Streptococcal antigens
• In this series, women are more often affected than men.
• One patient was asymptomatic, thus the importance of considering this diagnosis in asymptomatic patients.
• Up to 40% of patients present with joint pain and arthritis.
• Can show overlapping characteristics with granulomatous dermatoses and mixed connective tissue disease.
• Associated to neoplasms (benign and malignant solid tumors)?
• Clinicopathologic correlation is vital to render a diagnosis due to its heterogeneous presentation.

Highlights from the #dermpathJC session:

Thank you so much for attending and for reading this summary. We are so excited to plan yet another journal club for you next month. Stay tuned.

Kind regards!

DermpathJC