Amebic colitis simulating ulcerative colitis.

Henoch-Schönlein purpura (HSP) is a form of systemic vasculitis characterized by vascular wall deposits of predominantly IgA, typically involving small vessels in skin, gut, and glomeruli and associated with purpura, intestinal colic, hematuria, and arthralgia or arthritis. HSP nephritis leads to chronic renal failure in up to 20% of pediatric patients after 20 years of follow-up in selected series. The risk is related to the initial clinical presentation and is maximal (more than 50%) when initial signs are a combination of nephrotic and nephritic syndromes. Although less important, the risk persists for mild renal symptoms or when the patient has apparently completely recovered from the renal disease. Other types of non-IgA-related leukocytoclastic vasculitis may be difficult to discriminate from HSP, thus confounding the diagnosis. The clinical picture of HSP is often incomplete and renal signs can become manifest years after initial signs. When based on clinical signs only, the diagnosis of HSP can therefore be missed, and some patients risk developing silent chronic renal failure after decades without appropriate treatment. Patients can also be overdiagnosed as HSP and thus submitted to unnecessary follow-up. It is therefore important that HSP should be correctly diagnosed from the initial signs. As the finding of IgA deposits in vessel walls associated with the characteristic signs of small-vessel vasculitis is a sine qua non in the diagnosis, a skin biopsy should be performed for histological and immunofluorescence studies in cases of clinical suspicion of HSP. The systematic diagnostic use of a cutaneous biopsy should not only improve the follow-up of patients with HSP but will also allow a reliable epidemiological study of vasculitis in children and a better knowledge of the disease.

Biopsy↗

PubMed2003

New insights into diabetic polyneuropathy.

Patients with complaints of numbness, tingling, and dysesthesias in the toes and feet are frequently referred to neurologists. Often, the only objective evidence for peripheral nerve dysfunction in these patients is limited to small-caliber sensory nerve fibers. On examination these patients may have reduced distal pinprick sensation, and distal leg skin biopsies show loss of small-caliber nerve fibers. Studies focusing on small-caliber nerve fibers have led to a growing impression that neuropathy can be associated with early diabetes or impaired glucose tolerance (IGT). Often, neuropathy can be the presenting symptom of either diabetes or IGT. Furthermore, the oral glucose tolerance test appears to be a more sensitive measure of glucose dysmetabolism in these patients than levels of fasting blood glucose or glycated hemoglobin. Patients with IGT-associated neuropathy may represent an attractive target population for future regenerative studies given that their neuropathy is less severe and presumably more easily reversed than neuropathy occurring in patients with diabetes.Historically, small-caliber fibers have not been extensively evaluated due to a lack of objective measures. Several measures to evaluate these fibers are emerging, including skin biopsy with visualization of epidermal nerve fibers. The accessibility of epidermal nerve fibers makes them an attractive target for nerve injury models, which have potential for development as novel outcome measures. Such approaches may address some of the challenges of past diabetic polyneuropathy trials.

Biopsy↗