Acute Hemorrhagic Edema of Infancy: Still a Challenge for the Pediatrician.

We report a case of acute hemorrhagic edema of infancy (AHEI) occurred in an 11-month-old male infant after upper respiratory tract infection. The onset was dramatic with petechiae, ecchymosis, and annular, nummular, or targetoid purpuric plaques on the extremities, face, and ears. Acute hemorrhagic edema of infancy is a benign form of leukocytoclastic vasculitis that typically affects children between 4 and 24 months of age. The etiology remains still unknown. The potential triggers of AHEI include preceding bacterial or viral infections, immunizations, and drugs. Although the clinical picture is fearful, in the majority of cases, it involves only cutaneous small vessels. Recognizing this as a distinct clinical entity allows to establish an appropriate prognosis for this rare benign disease in children.This report could be a helpful reminder, especially for emergency physicians, to discriminate AHEI from other more severe diseases, such as meningococcal sepsis.

Toll-like receptors, immunoproteasome and regulatory T cells in children with Henoch-Schönlein purpura and primary IgA nephropathy.

BACKGROUND: Henoch-Schönlein purpura (HSP) nephritis and primary IgA nephropathy (pIgAN) present with glomerular IgA deposits, but differ with regard to clinical features. The suspected involvement of different immune system pathways is largely unknown. METHODS: This study was aimed at investigating some of the immunological features including Toll-like receptors (TLR), proteasome (PS)/immunoproteasome (iPS) switch, and the regulatory T cell system (Treg/Th17 cells) in 63 children with HSP with/without renal involvement and in 25 with pIgAN. Real-time PRC (Taqman) was used to quantify mRNA levels in peripheral blood mononuclear cells (PBMC). RESULTS: The expression of mRNAs encoding for TLR4 in both HSP and pIgAN was higher than in controls (HC) and in both diseases FoxP3mRNA and TGF-ß1mRNA expression was significantly lower than in HC. A switch from PS to iPS (LMP2/ß1) was detected only in PBMC of HSP and it correlated with the level of TLR2mRNA, which was selectively increased only in children with HSP. CONCLUSION: Children with HSP and pIgAN present with similar signs of engagement of the innate immunity and regulatory T cell depression. The increased immunoproteasome switch, which correlated with TLR2 activation, may suggest an innate immunity pathway peculiar to HSP vasculitic presentation. This research area also deserves further investigation for possible therapeutic applications.