Endocrine Abstracts

JOINT406

Introduction and Background: The coexistence of multiple autoimmune diseases either systemic or organ-specific has been described in the literature. Here, we report a case of Latent Autoimmune Diabetes in Adults (LADA) associated with cutaneous systemic scleroderma (SSc), a rare and scarcely documented entity.

Case Report: A 41-year-old man, diagnosed with LADA two years prior, was treated with a basal-bolus insulin regimen. Concurrently, the patient developed symptoms of malabsorption, including chronic non-bloody watery diarrhea, abdominal pain, weight loss, iron deficiency anemia, hypoalbuminemia, and significant glycemic instability. Auto immune Adrenal insufficiency, thyroidis, and celiac disease were excluded. Colonoscopy with biopsy confirmed the diagnosis of microscopic colitis, collagenous subtype. Two years later, the patient presented with progressive diffuse thickening and hardening of the skin, accompanied by limited joint mobility, particularly in the lower limbs.A cutaneous biopsy revealed sclerodermiform features, with significant fibrosis and no evidence of malignancy, consistent with systemic sclerosis.

Discussion: Collagenous colitis, one of the primary subtypes of microscopic colitis (MC), is a chronic inflammatory condition of the colon characterized by watery diarrhea. Although the exact etiology remains unclear, autoimmune dysfunction has been strongly involved, as evidenced by its association with various autoimmune comorbidities. Auto-immune diabetes caracterized by the destruction of pancreatic β-cells, has also been linked to MC. A nationwide matched case–control study in Sweden reported an 80% increased prevalence of Type 1 Diabetes in MC patients compared to the general population, with a stronger association observed for collagenous colitis than lymphocytic colitis. Systemic sclerosis (SSc) is an autoimmune connective tissue disorder marked by fibrosis and commonly presenting with skin involvement. Cases of coexistence between autoimmune diabetes and SSc are rare, and the underlying mechanisms remain poorly understood. Interferons are believed to play a significant role as immunomodulators and inhibitors of collagen production. In this case, the histopathology was characteristic of systemic sclerosis. However, distinguishing between diffuse skin hardening caused by systemic sclerosis and other conditions, such as scleroderma-like syndrome or diabetic scleroderma, can be challenging. Diabetic scleroderma is attributed to the non-enzymatic glycation of collagen. Chronic hyperglycemia may stimulate fibroblast proliferation and extracellular matrix production, contributing to skin hardening.

Conclusion: This case highlights the need to recognize rare autoimmune associations and integrate routine screening for comorbidities in patients with autoimmune backgrounds. Further research is needed to elucidate underlying mechanisms and improve therapeutic approaches.