What is Segmental Erythema?

Erythema nodosum is a common disease in young women, which is generally a complication caused by drugs. Common drugs include bromides and sulfonamides, which can cause patients to develop small red papules on the skin. These papules are arranged in clusters, forming nodules. Common sites of onset include the thighs, arms, and breasts. Additionally, patients may also experience loss of appetite and fever, and timely treatment is necessary.

1. Streptococcus infection: Some patients may develop erythema nodosum following upper respiratory infections, angina, and acute tonsillitis. According to domestic reports, approximately 68.2% of patients have rheumatic-like joint pain, 25.6% have tonsillitis, while the incidence reported in other studies is relatively low. This suggests that the disease is associated with streptococcus infection, but it is not the only causative factor.

2. Tuberculosis infection: Since Uffelmana proposed the association between erythema nodosum and tuberculosis infection in 1872, this connection has gradually garnered attention. Increasing evidence suggests a close relationship between erythema nodosum and tuberculosis infection. Domestic statistics indicate that more than 60% of patients with erythema nodosum have concurrent tuberculosis infection, old tuberculosis lesions, or positive tuberculin tests. It is believed that the disease is an allergic phenomenon of the body to tuberculosis bacteria or their toxins.

3. Other causes: Certain drugs, especially bromides and sulfonamides, are the most common causative agents of erythema nodosum. Other conditions such as coccidioidomycosis, histoplasmosis, cat-scratch disease, trichophytosis, ulcerative colitis, sarcoidosis, Behcet's disease, leprosy, and venereal granuloma may also be associated with erythema nodosum. Additionally, viral infections may be related to the disease, and rarer causes include acute vulvar ulcer, acute and chronic leukemia, which can also be accompanied by erythema nodosum.