What is your diagnosis for this 30-year-old woman?

She has had this tender plaques on her calves since years ago. The symptoms become more severe during the cold months of the year. Otherwise she was in good health.

Diagnosis: Erythema Induratum

Erythema induratum usually presents with recurring, tender, painful nodules on the calves, which often ulcerate and heal with scarring. It is much more common in females than in males. Bazin gave the name erythema induraturn to this disease when histologic examination revealed caseation necrosis and the lesions were associated with tuberculosis. It has been regarded as a manifestation of tuberculin hypersensitivity, a type of tuberculid occurring on the legs, whereas nodular vasculitis represents the nontuberculous counterpart. The number of reports of erythema induratum of Bazin is decreasing in most developed countries in accordance with the decreased incidence of tuberculosis.

Most authors currently consider erythema induratum of Bazin (nodular vasculitis) a multifactorial disorder with many different causes, tuberculosis being one of them.
here is no specific therapy. Most patients have remission of lesions with bed rest. Severe cases have been successfully treated with nonsteroidal anti-inflammatory drugs, dapsone, and prednisone. In the very rare case of nodular vasculitis associated with tuberculosis, appropriate antituberculous therapy is indicated.

Omid Zargari, MD

Below, you can find more details sent by our colleague Dr. Mehravaran from Hungary;

Nodular Vasculitis

Synonym: Erythema Induratum (Bazin 1861)

Epidemiology: Nodular vasculitis is an chronic disease of middle-age women (as in this case). It is more likely to affect patients with poor circulation in their legs, as manifested by erythrocyanoosis, cold pasty skin, lidedo reticularis, perforicullar erythema, or pernio. Perhaps 5-10% of cases are described in men; these patients are probably more likely to have evidence of tuberculosis.

Etilogy and pathogenesis:  Pplymerase chain reaction (PCR) reveal Mycobacterium tuberculosis in many of these lesions. In other patients, there is clear evidence of tuberculosis elsewhere, reinforcing the concept of tuberculid. Thus, to this erythema induratum as tuberculosis-related panniculitis, and nodular vasculitis as a clinically similar disorder without evidenc of M.tuberculosis infection. If tuberculosis is not identified, no other etiology is found in most instances.

Clinical findings

Nodular vasculitis usually presents as red-brown nodules on the calves rather than over the shins as in the case with erythema nodosum. The nodules may enlarge into plaques; they are painful, may liquefy, often ulcerate, and heal very slowly. New lesions tend to appear as older one heal. The disease often flares with the onset of cold weather (as in this case). Lesions can  occur anywhere on the body and be unilateral. Almost all patiens have acrocyanosis, cutis marmorata, pernio, and other sign of cold intolerance. 

Histopathology

The picture combines vasculitis with fat necrosis. Mild-sized septal arterries whos thickened walls, intramural lymphocytic infilterates, narrowed lumens, and often thrombi. The septa are thickened. In adddition, there is panlobar fat necrosis with nuclear debris and peripheral granulomas. 

Laboratory. Tuberculosis should be sought. Specimen can be evaluated with PCR to identify the DNA of the organisms. 

Differential Diagnosis. Other forms of panniculitis, especially alfa1-antitrypsin deficiency and pancreatic disease, can have silmilar appearance, likewise for cutaneous perarthritis nodosa (biopsy reveal in volvement of a larger vessel, ususally in the deep dermis, with minimal fatty change). Pernio of the calves features dense pervascular lymphocytic infilterates arranged  in onion-like layers around the deep dermal vessels without panniculitis. 

Treatment

• If M.tuberculosis is found, the patient should be treated with anti-tuberculotic agents.
• Compression stocking are also essential as well as keeping the legs warm and dry.
• Other options, when there is no evidence for tuberculosis, include systemic corticosteroids and potassium iodide.

References:

1.      Braun-Falco’s Dermatology (third edition): 2009