Before getting into the details, let us first name all possible causes of this disease: bacterial infections, fungal infections, enteropathies, drugs, Behçet disease, sarcoidosis. Doctors name a streptococcal infection the most widespread source of the problem. This sort of infection hurts kids. At the same time, grown-ups suffer from the similar problem, known as sarcoidosis supported by the same infection which attacks childish organism.  Tuberculosis is another famous predecessor of erythema nodosum. Other bacteria are responsible for the developing disease as well. As for the fungal infections, it is important to recall Coccidioidomycosis.