Systemic manifestations of erythema nodosum.

The systemic manifestations accompanying erythema nodosum can be differentiated from those associated with the precipitating infectious process and from coincident disease processes. Erythema nodosum itself is characterized by (a) skin lesions at pressure sites, (b) malaise, fever and occasionally chills, (c) arthritis (70 per cent) and (d) over-reactivity of tissue. Tissue hypersensitivity is most pronounced at sites of trauma, at sites of specific skin testing, and in the lymphoid system draining infections in the pharynx and lung. Common infections of the respiratory tract most often antedate attacks of erythema nodosum. In New England, a beta-hemolytic streptococcus infection is a common causative factor, and tuberculosis is an unusual causative factor. In endemic areas, coccidioidomycosis is a common cause of erythema nodosum. The most important coincidental disease process is rheumatic heart disease. Rarely is it a sequel of erythema nodosum. Other "collagen diseases" may coexist with erythema nodosum. Erythema nodosum is its own most common complication. Follow-up studies indicate that over half of the patients have a subsequent attack, and a certain number have recurrent episodes for months to years. The management of erythema nodosum is expectant. In each case the cause should be found and treated. Steroid treatment is rarely justified, and should be used only after tuberculosis and other treatable entities have been ruled out.