Purpura fulminans: recognition, diagnosis and management

Diagnostic value of polymerase chain reaction analysis of skin biopsies in purpura fulminans

Even though prompt diagnosis and treatment of purpura fulminans (PF) is essential to reduce mortality, early administration of antibiotics may preclude identification of the causative agent by standard bacterial cultures and thus render definitive diagnosis impossible. Here we present a case of an infant with PF and negative bacterial cultures for whom polymerase chain reaction (PCR) analysis of a cutaneous biopsy specimen obtained 4 days after initiation of antibiotics identified the genomic sequence of Neisseria meningitidis genogroup C. When bacterial cultures fail to provide useful information, PCR of skin biopsy specimens can be a valuable diagnostic tool in PF.

Neonatal purpura fulminans manifestation in early-onset group B Streptococcal infection

Patient: Male, 0

Final Diagnosis: Purpura fulminans

Symptoms: Fever • letargy

Medication: —

Clinical Procedure: —

Specialty: Pediatrics and Neonatology

Protein C deficiency as the major cause of thrombophilias in childhood

Genetic predisposition of thromboembolism depends on the racial background. Factor V Leiden (G1691A) and factor II mutation (G20210A) are the leading causes of inherited thrombophilias in Caucasians, but are not found in Asian ancestries. Protein S (PS), protein C (PC) and antithrombin (AT) activity are reportedly low in 65% of adult Japanese patients with deep vein thrombosis. Approximately half of the patients with each deficiency carry the heterozygous mutation of PS (PROS1; 20%), PC (PROC; 10%), and AT genes (SERPINC1: 5%). Recently, several studies have revealed an outline of inherited thrombophilias in Japanese children. Congenital thrombophilias in 48 patients less than age 20 years consisted of 45% PC deficiency, 15% PS deficiency and 10% AT deficiency, along with other causes. All PS- and AT-deficient patients had a heterozygous mutation of the respective gene. On the other hand, PC-deficient patients were considered to carry the homozygous or compound heterozygous mutation in 50%, the heterozygous mutation in 25%, and unknown causes in the remaining 25% of patients. Half of unrelated patients with homozygous or compound heterozygous PROC mutations carried PC-nagoya (1362delG), while their parents with its heterozygous mutation were asymptomatic. Most of the PC-deficient patients developed intracranial lesion and/or purpura fulminans within 2 weeks after birth. Non-inherited PC deficiency also conveyed thromboembolic events in early infancy. The molecular epidemiology of thrombosis in Asian children would provide a clue to establish the early intervention and optimal anticoagulant therapy in pediatric PC deficiency.

The skin and hypercoagulable states

Hypercoagulable states (HS) are inherited or acquired conditions that predispose an individual to venous and/or arterial thrombosis. The dermatologist can play a vital role in diagnosing a patient's HS by recognizing the associated cutaneous manifestations, such as purpura, purpura fulminans, livedo reticularis, livedo vasculopathy (atrophie blanche), anetoderma, chronic venous ulcers, and superficial venous thrombosis. The cutaneous manifestations of HS are generally nonspecific, but identification of an abnormal finding can warrant a further workup for an underlying thrombophilic disorder. This review will focus on the basic science of hemostasis, the evaluation of HS, the skin manifestations associated with hypercoagulability, and the use of antiplatelet and anticoagulant therapy in dermatology.

Neonatal asphyxia and renal failure as the presentation of non-inherited protein C deficiency

Inherited or acquired protein C (PC) deficiency leads to thromboembolic events. Plasma PC activity in infancy is physiologically lower than in adults. We describe a case of neonatal asphyxia and acute renal failure associated with isolated PC deficiency. A full-term male infant was born to a healthy mother by caesarean section because of fetal distress. The small-for-gestational age infant showed 2 and 7 of Apgar scores at 1 and 5 minutes, respectively. Hypercoagulability required repeated infusions of fresh frozen plasma. Coagulation study revealed PC activity, 6%, protein S activity, 61%, and high D-dimer levels, along with normal factor VII activity and absent vitamin K deficiency. Anticoagulant and activated PC therapy improved coagulopathy and nephropathy. Imaging analyses indicated no visceral infarctions. Renal function and PC activity have been slowly normalized until 6 months of age. He had no PROC mutation or PC-deficient parents. Selective PC deficiency may occur as an acquired cause of hypercoagulable crisis in the stressed newborn.

Antibody SPC-54 provides acute in vivo blockage of the murine protein C system

Multiple protective effects of pharmacological activated protein C (APC) are reported in several organ pathologies. To help evaluate the endogenous murine PC system, we characterized a rat monoclonal anti-mouse PC antibody, SPC-54, which inhibited the amidolytic and anticoagulant activities of murine APC by>95%. SPC-54 blocked active site titration of purified APC using the active site titrant, biotinylated FPR-chloromethylketone, showing that SPC-54 blocks access to APC's active site to inhibit all enzymatic activity. A single injection of SPC-54 (10mg/kg) neutralized circulating PC in mice for at least 7days, and immunoblotting and immuno-precipitation with protein G-agarose confirmed that SPC-54 in vivo was bound to PC in plasma. Pre-infusion of SPC-54 in tissue factor-induced murine acute thromboembolism experiments caused a major decrease in mean survival time compared to controls (7min vs. 42.5min, P=0.0016). SPC-54 decreased lung perfusion in this model by 54% when monitored by vascular perfusion methodologies using infrared fluorescence of Evans blue dye. In LD50 endotoxemia murine models, SPC-54 infused at 7hr after endotoxin administration increased mortality from 42% to 100% (P<0.001). In summary, monoclonal antibody SPC-54 ablates in vitro and in vivo APC protective functions and enzymatic activity. The ability of SPC-54 to block the endogenous PC/APC system provides a powerful tool to understand better the role of the endogenous PC system in murine injury models and in cell bioassays and also to neutralize the enzymatic activities of murine APC in any assay system.

Adhesion of Neisseria meningitidis to dermal vessels leads to local vascular damage and purpura in a humanized mouse model

Septic shock caused by Neisseria meningitidis is typically rapidly evolving and often fatal despite antibiotic therapy. Further understanding of the mechanisms underlying the disease is necessary to reduce fatality rates. Postmortem samples from the characteristic purpuric rashes of the infection show bacterial aggregates in close association with microvessel endothelium but the species specificity of N. meningitidis has previously hindered the development of an in vivo model to study the role of adhesion on disease progression. Here we introduced human dermal microvessels into SCID/Beige mice by xenografting human skin. Bacteria injected intravenously exclusively associated with the human vessel endothelium in the skin graft. Infection was accompanied by a potent inflammatory response with the secretion of human inflammatory cytokines and recruitment of inflammatory cells. Importantly, infection also led to local vascular damage with hemostasis, thrombosis, vascular leakage and finally purpura in the grafted skin, replicating the clinical presentation for the first time in an animal model. The adhesive properties of the type IV pili of N. meningitidis were found to be the main mediator of association with the dermal microvessels in vivo. Bacterial mutants with altered type IV pili function also did not trigger inflammation or lead to vascular damage. This work demonstrates that local type IV pili mediated adhesion of N. meningitidis to the vascular wall, as opposed to circulating bacteria, determines vascular dysfunction in meningococcemia.

Plastic surgical treatment of purpura fulminans: Long-term follow-up of two patients

Purpura fulminans (PF) is a rapidly progressing, potentially life-threatening condition characterised by disseminated intravascular coagulation (DIC) and haemorrhagic infarction of the skin. Plastic surgical treatment of PF has never been reported in Scandinavia. The aim of this report was to review plastic surgical treatment of PF and the long-term results of two patients treated in our department. Both patients presented to a community hospital with skin lesions looking like simple traumatic skin bleeds a period after a Varicella infection. They were initially treated at the community hospitals with broad-spectrum antibiotics and adjunctive therapies. When their condition permitted, they were transferred to the department of paediatrics of Skåne University Hospital where their DIC was treated further. The patients were transferred to the department of plastic and reconstructive surgery, when medically stable, and operated on with debridement, and amputation of a toe in one patient, and the application of autologous skin grafts. The children made an excellent recovery and were discharged home after 1.5 months and 3 weeks, respectively. At follow-up, 14 years and 8 years later, respectively, the patients were fully recovered and no secondary corrections were indicated. In conclusion, debridement of necrotic tissue should be performed in a department of plastic and reconstructive surgery as soon as the child is clinically stable, and skin grafting when the wound bed permits it. Follow-up should be performed in the same fashion as for full-thickness burns.

Protein C anticoagulant and cytoprotective pathways

Plasma protein C is a serine protease zymogen that is transformed into the active, trypsin-like protease, activated protein C (APC), which can exert multiple activities. For its anticoagulant action, APC causes inactivation of the procoagulant cofactors, factors Va and VIIIa, by limited proteolysis, and APC's anticoagulant activity is promoted by protein S, various lipids, high-density lipoprotein, and factor V. Hereditary heterozygous deficiency of protein C or protein S is linked to moderately increased risk for venous thrombosis, while a severe or total deficiency of either protein is linked to neonatal purpura fulminans. In recent years, the beneficial direct effects of APC on cells which are mediated by several specific receptors have become the focus of much attention. APC-induced signaling can promote multiple cytoprotective actions which can minimize injuries in various preclinical animal injury models. Remarkably, pharmacologic therapy using APC demonstrates substantial neuroprotective effects in various murine injury models, including ischemic stroke. This review summarizes the molecules that are central to the protein C pathways, the relationship of pathway deficiencies to venous thrombosis risk, and mechanisms for the beneficial effects of APC.

[Hemorrhagic skin lesions associated with infections]

Eine Vielzahl von bakteriellen, viralen oder parasitären Infektionserkrankungen kann mit hämorrhagischen Effloreszenzen einhergehen. Die Symptomkonstellation Fieber und Petechien kann Vorbote einer fulminanten bakteriellen Sepsis sein, die einer sofortigen intensiven Therapie zugeführt werden muss. Viel häufiger liegt der Symptomatik aber ein harmloser selbstlimitierender Virusinfekt zugrund, sodass man in Bezug auf das Ausmaß der notwendigen Diagnostik vor einem Dilemma steht. Der vorliegende Beitrag gibt eine Übersicht über die Differenzialdiagnosen und Pathophysiologie infektionsassoziierter Hautblutungen, und es wird ein differenzialdiagnostischer Algorithmus für die Diagnosefindung bei der Konstellation Fieber plus Petechien vorgeschlagen.