Erythema Nodosum

Idiopathic Granulomatous Mastitis (IGM) is mostly described as an autoimmune disease with high prevalence among Middle Eastern childbearing-age women. The current study aimed to evaluate the best treatment of choice in patients with resistant or recurrent IGM.

Patients with established recurrent or resistant IGM who were referred to the breast cancer research center from 2017 to 2020 were randomly assigned to either one of the following treatment groups: A (Best supportive care), B (corticosteroids: prednisolone), and C (methotrexate and low dose corticosteroids). This adaptive clinical trial evaluated radiological and clinical responses, as well as the possible side effects, on a regular basis in each group, with patients followed up for a minimum of 2 years.

A total of 318 participants, with a mean age of 33.52 ± 6.77 years, were divided into groups A (10 patients), B (78 patients), and C (230 patients). In group A, no therapeutic response was observed; group B exhibited a mixed response, with 14.1% experiencing complete or partial responses, 7.7% maintaining stability, and 78.2% experiencing disease progression. Accordingly, groups A and B were terminated due to inadequate response. In group C, 94.3% achieved complete response, 3% partial remission, and 2.7% no response. Among the entire patient cohort, 11.6% tested positive for anti-nuclear antibodies (ANA), 3.5% for angiotensin-converting enzyme (ACE), and 12.3% for erythema nodosum (EN). Notably, hypothyroidism was a prevalent condition among the patients, affecting 7.2% of the cohort. Furthermore, the incidence of common side effects was consistent across all groups.

The most effective treatment option for patients with recurrent or resistant idiopathic granulomatous mastitis is a combination therapy involving steroids and disease-modifying antirheumatic drugs such as methotrexate.

Previous studies have demonstrated the coexistence of erythema nodosum (EN) and inflammatory bowel disease (IBD), while the exact etiology of the co-occurrence of the two disorders remains uncertain.

A bidirectional two-sample Mendelian randomization (MR) design was employed to determine the causal link between EN and IBD. Genetic variations associated with Crohn's disease (CD) and ulcerative colitis (UC) were derived from accessible genome-wide association studies pertaining to European ancestry. The FinnGen database was used to find the genetic variations containing EN. In the forward model, IBD was identified as the exposure, whereas in the reverse model, EN was identified as the exposure. The causal link between IBD and EN was examined using a range of different analysis techniques, the primary one being the inverse variance weighted (IVW) method, including inverse variance weighted-fixed effects (IVW-FE) and inverse-variance weighted-multiplicative random effects (IVW-MRE). To strengthen the results, assessments of sensitivity, heterogeneity, and pleiotropy were also conducted.

MR results showed that IBD increased the risk of EN (IVW-MRE: OR = 1.242, 95% CI = 1.068-1.443, p = 0.005). Furthermore, there was a strong correlation found between CD and a higher risk of EN (IVW-FE: OR = 1.250, 95% CI = 1.119-1.396, p = 8.036 × 10^-5 ). However, UC did not appear to be linked to EN (IVW-FE: OR = 1.104, 95% CI = 0.868-1.405, p = 0.421). The reverse MR analysis findings did not imply that EN was linked to IBD. Horizontal pleiotropy did not appear to exist, and the robustness of these findings was confirmed.

The current investigation found that in European populations, IBD and its subtype CD could raise the incidence of EN.