Erythema nodosum as sign of primary tuberculosis.

Erythema nodosum is a panniculitis associated with numerous diseases such as infections, inflammatory diseases, tuberculosis or can be idiopathic. We here report a case of a woman with erythema nodosum and reactive arthritis who was subsequently diagnosed with tuberculosis. A high level of suspicion and a thorough clinical and laboratory investigation of the patient presenting with erythema nodosum is required, in order to detect a possible systemic underlying condition.