[Interstitial granulomatous dermatitis with arthritis].

Interstitial granulomatous dermatitis with arthritis is a rare dermatologic disorder seen in patients suffering from diseases in which circulating immune complexes occur. The typical cutaneous signs are linear cords usually located on the lateral aspect of the trunk. The characteristic, although not specific, histology reveals a dense diffuse infiltrate composed mostly of histiocytes, accompanied by neutrophils and eosinophils, and degenerated collagen surrounded by palisades of histiocytes. We discuss this disorder and its differential diagnosis.