dermatologic disorders
Erythema Nodosum
Diagnosis of Erythema Nodosum
Clinical evaluation Excisional biopsy Diagnosis of erythema nodosum is usually by clinical appearance and can be confirmed by excisional biopsy of a nodule when necessary. A diagnosis of erythema nodosum should prompt evaluation for causes. Evaluation might include biopsy, tuberculosis skin testing (PPD or anergy panel), antinuclear antibodies, complete blood count, chest x-ray, and serial antistreptolysin O titers or a pharyngeal culture. Erythrocyte sedimentation rate is often high. 