Clinical cases
Erythema Nodosum Migrans with a chronic course
In the special litarature have been described several clinical variants of erythema nodosum. These are erythema nodosum migrans, subacute nodular migratory panniculitis Vilanova-Pinol and chronic erythema nodosum.

Clinical case
A 56-year-old male patient presented with a 3-year history of gradually enlarging, tender, erythematous to brownish nodular plaques and placards on his lower limbs, with prominent serpiginous margins and a sclerodermiform white center. Histopathological examination showed thickening of the septa of subcutaneous fat, with prominent leukocytic infiltrate mainly composed of lymphocytes in a perivascular disposition. Treatment with potassium iodide 600-900 mg/day was made.

Erythema nodosum migrans was first described by Bafverstedt in 1954 as an entity clinically different from classic erythema nodosum, but with identical histopathologic findings. Subacute nodular migratory panniculitis and chronic erythema nodosum are also considered by some authors as different entities of erythema nodosum. Histologically, erythema nodosum migrans shows greater septal thickening, with an abundant number of granulomas containing frequent multinucleated giant cells. Erythema nodosum migrans, subacute nodular migratory panniculitis, and chronic erythema nodosum are clinical variants that may all be included within the spectrum of erythema nodosum.

Our patient showed typical clinical features of erythema nodosum migrans, with a chronic course due to repeated relapses, without any aetiological factors that could be identified.