Background and Aims: Altered vascular flow is known to both play a role in the pathogenesis and influence the severity of inflammatory bowel disease (IBD). This phenomenon has been described in other systemic conditions and contributes to disease progression by facilitating inflammation and thrombosis. Microvascular dysfunction may represent an early sign of generalized vascular disease (VD). It manifests by failure to achieve a normal response of vasodilation and increased blood flow following a period of vaso-occlusion. Although thromboembolic complications are well described in IBD, their pathogenesis is not fully understood. This study sought to assess microvascular responsiveness in pediatric subjects with IBD, by recording postocclusion peripheral arterial pulsatile volume changes. Patients and Methods: A total of 32 pediatric subjects were studied, including 16 with IBD and 16 age-matched controls. All patients with IBD were in clinical remission, and none had known VD. Vascular reactivity was evaluated using the Itamar Medical EndoPAT2000, a noninvasive device utilizing plethysmography to measure microvascular flow. Results were reported as the reactive hyperemia index (RHI), indicating post- to preocclusion pulsatile volume changes. Results: Baseline characteristics, including body mass index, plasma lipid levels, hemoglobin, and serum albumin, were similar in both study groups. All patients with IBD were in clinical remission, assessed by standard disease activity scoring methods. Measurements of microvascular function indicated patients with IBD exhibited a mean RHI both within the range associated with VD risk in adults (≤1.67) and significantly lower than that in controls (IBD vs control = 1.66 vs 2.02, P = 0.036). Conclusions: Microvascular plethysmography is a safe and noninvasive method for assessing microvascular function in children with IBD. Patients with IBD in clinical remission demonstrate an attenuated, postocclusion microvascular hyperemic response, compared with the normal response in controls. These findings suggest pediatric IBD subjects with a mean RHI within the VD “at risk” range should be monitored for thromboembolic phenomena. Further studies in a larger patient population and over longer periods should be conducted to validate our findings and to determine the importance of these measurements in guiding IBD management.

Pyoderma gangrenosum (PG) is a rare, necrotizing dermatologic condition associated with neoplastic and immune dysregulatory states, including adult and pediatric inflammatory bowel disease (IBD). Over the last decade, the elucidation of inflammatory mediators in PG has led to a plethora of localized and systemic corticosteroid sparing therapies including antibiotics, antiinflammatory, and immunomodulatory agents. Herein, we describe the case of a 17-year-old female with ulcerative colitis in clinical remission, who presented with a long-standing, large, deep, and painful lower extremity PG lesion. Following failed attempts both at local and at systemic therapies, her PG was successfully treated with the tumor necrosis factor-alpha (TNF-α) monoclonal antibody adalimumab, and the lesion remains in remission after four years of subcutaneous anti-TNF therapy. This case serves as the basis for our presenting a review of the pathogenesis, diagnostic criteria, differential diagnosis, therapies and treatment outcomes for pediatric IBD-associated PG. Our experience adds to earlier reports suggesting anti-TNF-α biologic therapy is most likely to achieve long-term resolution of IBD-associated PG in children and adolescents with severe lesions or who failed other treatments.