Erythema Elevatum Diutinum
Erythema elevatum diutinum (EED) is a very rare, chronic form of cutaneous small-vessel vasculitis. It presents as dark red, purple or yellow-brown papules, plaques or nodules, usually arranged symmetrically over the extensor surfaces of the joints (elbows, knees, backs of the hands and feet, heels). At its core, EED is a chronic leukocytoclastic vasculitis (LCV) driven by repeated deposition of immune complexes. Over time, lesions evolve from an acute vasculitic stage to dermal fibrosis, new vessel formation and lipoprotein deposits in the tissue, producing a xanthoma-like appearance (extracellular cholesterosis). The disease is often linked to chronic infections (particularly HIV, hepatitis and streptococcal infection), autoimmune disease, or lymphoproliferative/myeloproliferative disorders (such as IgA monoclonal gammopathy). At Haute-Derma, we combine staged histopathologic diagnosis, screening for associated systemic disease and a dedicated treatment plan built around dapsone, together with laser resurfacing of fibrotic tissue.
How the disease develops in the skin and immune system:
- Persistent Immune Complex Deposition and Complement Activation:
- Antigens that circulate over long periods (from bacteria, viruses or tumor cells) drive the formation of IgA or IgG immune complexes.
- These complexes keep settling in the postcapillary venules of the superficial and mid dermis, where the extensor skin over joints is subject to mechanical stretch and lower temperatures.
- Complement activation recruits neutrophils, producing an LCV reaction that smolders and recurs over many years.
- Fibroblast Proliferation and Dermal Fibrosis:
- Unlike acute LCV, which either resolves on its own or causes rapid necrosis, the inflammation in EED prompts endothelial cells and fibroblasts to release large amounts of growth factors (TGF-β, VEGF).
- The result is dense new vessel growth and excess coarse collagen in the dermis, which turns faint, flat hemorrhagic papules into firm nodules and plaques that stand clearly above the skin.
- Extracellular Lipoprotein Deposition (Extracellular Cholesterosis):
- Chronically leaky vessel walls allow serum lipoproteins to escape into the dermal interstitium.
- Macrophages engulf the lipoproteins and become foam cells; together with free cholesterol deposited in the long-standing dermis, this gives older EED lesions a pale yellow or dark brown color resembling a xanthoma.
Skin Findings in Erythema Elevatum Diutinum (EED)
| Clinical feature | What it looks like | Cellular and molecular mechanism |
|---|---|---|
| Symmetric plaques/nodules over extensor joints | Raised papules, plaques or nodules, firm or hyperkeratotic, purple-red, brick-brown or gray-yellow; symmetric on the elbows, knees, backs of the hands and heels. | Chronic LCV combined with collagen proliferation and new vessel formation in areas exposed to friction and movement. |
| Xanthoma-like lesions | Older plaques turn yellow-orange or dark brown, with a smooth shiny or rough surface, and feel firm like fibrous tissue. | Extracellular lipoprotein deposits and infiltration by lipid-laden macrophages (foam cells) in late-stage disease. |
| Local symptoms (pain, burning, restricted movement) | Lesions may ache or burn slightly when the joint is stretched; large nodules on the fingers or elbows can limit bending and straightening. | Dermal inflammation presses on sensory nerve endings, and bulky tissue mechanically restricts the soft tissue around the joint. |
| Vesicles / hemorrhagic bullae | Seen in the acute phase: blisters on a red plaque that rupture easily, leaving shallow erosions. | Fibrinoid necrosis and marked red blood cell extravasation in dermal venules during an acute flare. |
| Signs of associated systemic disease | Low-grade fever, small-joint pain, or signs of an underlying infection (HIV) or blood disorder (IgA monoclonal gammopathy). | A systemic autoimmune response or abnormal proliferation of IgA-secreting B cells/plasma cells. |
EED vs. Other Nodular and Fibrotic Skin Conditions
| Erythema Elevatum Diutinum (EED) | Tuberous Xanthoma | Granuloma Annulare |
|---|---|---|
| Extensor surfaces of joints, backs of hands/feet | Pressure areas: elbows, knees, buttocks | Backs of hands/feet, neck, trunk |
| Purple-red, turning yellow-brown / brick-gray | Yellow-orange or pale pink | Skin-colored, pale pink or faintly violet |
| Chronic LCV + fibrosis + lipid deposits | Predominantly foam cells, no vasculitis | Central collagen degeneration + palisading macrophages |
| Often painful or stinging during flares | Painless | Painless, occasionally mildly itchy |
| Rapid, specific response to dapsone | No response to dapsone | Poor or inconsistent response to dapsone |
Our Approach
At Haute-Derma, we work up patients with erythema elevatum diutinum systematically:
- Clinical Pattern and Lesion Distribution:
- Careful examination of the symmetric raised plaques over the extensor joints and the backs of the hands and feet.
- Staging the lesions: soft, purple-red (acute vasculitis) vs. firm, yellow-brown (established fibrosis and lipid deposition).
- Multi-Site Skin Biopsy (Histopathology):
- Punch biopsies of both a new (early) lesion and an older lesion are needed for comparison.
- Early lesions: classic LCV with fibrinoid necrosis of vessel walls, neutrophilic infiltrate and nuclear dust (leukocytoclasia).
- Late lesions: endothelial proliferation, dense collagen, foam cells and extracellular lipid (extracellular cholesterosis).
- Screening for Underlying Systemic Disease:
- Serum protein electrophoresis (SPEP) and immunofixation electrophoresis (IFE) to detect a monoclonal gammopathy (especially IgA monoclonal gammopathy).
- Serology for HIV and hepatitis B/C, plus a search for chronic infection (dental, ear-nose-throat, streptococcal – ASO titer).
- Autoimmune markers: ANA and rheumatoid factor (RF).
Treatment Options at Haute-Derma
Our EED treatment plan combines an oral drug that specifically modulates neutrophil function with local procedures aimed at the fibrotic tissue:
- Dapsone (First-Line Treatment):
- Dapsone (50–150 mg/day) is the first-line treatment for EED because it strongly inhibits neutrophil adhesion, migration and release of proteolytic enzymes. Patients usually respond quickly, with less pain and burning and flattening of inflamed lesions within days to a few weeks.
- Required before starting: G6PD testing to avoid the risk of hemolysis. Complete blood count and methemoglobin levels are monitored regularly.
- Alternatives if dapsone is not tolerated: colchicine, sulfasalazine, or a short course of oral corticosteroids during flares.
- Procedures for Fibrotic Plaques and Nodules at Haute-Derma:
- Intralesional triamcinolone acetonide: used for late fibrotic nodules that are no longer very inflamed but remain thick and hard, to soften the fibrous tissue and flatten it quickly.
- Fractional CO2 laser: gently ablates raised fibrotic, hyperkeratotic lesions and resurfaces the skin around the joints so it becomes smoother and flatter.
- Light Therapy and Joint Care:
- Red LED (630 nm) combined with near-infrared LED (830 nm) helps reduce interstitial inflammation, stimulate microcirculation and ease pain and burning on movement.
- Advice on protecting the joints and avoiding repeated friction or trauma (the Koebner phenomenon) to prevent new lesions from appearing.
