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Vascular Disorders
Published in Genesio Murano, Rodger L. Bick, Basic Concepts of Hemostasis and Thrombosis, 2019
Osteogenesis imperfecta (brittle bones and blue sclerae) is one of the more common hereditary collagen vascular diseases and is inherited as an autosomal dominant trait.6 The disorder is characterized by a patchy lack of bone matrix. However, the matrix that does exist undergoes normal calcification. Osteogenesis imperfecta is clinically manifest as deformed and brittle bones that fracture easily. In addition, skin and subcutaneous hemorrhages are characteristic. Death commonly occurs at childbirth due to intracranial hemorrhage caused by an abnormal calvarium coupled with a vascular hemorrhagic diathesis. Easy and spontaneous bruisability, hemoptysis, epistaxis, and intracranial bleeding are common in osteogenesis imperfecta. An abnormal bleeding time and a positive tourniquet test are characteristic.7 In addition, many cases have been described with abnormal platelet function, as defined by adhesion and aggregation studies. The basic pathophysiology of osteogenesis imperfecta appears to be related to the inability of reticulin to mature into collagen. In addition, the collagen present demonstrates an abnormal amino acid composition.4
The arteries, veins and lymphatics
Published in Kevin G Burnand, John Black, Steven A Corbett, William EG Thomas, Norman L Browse, Browse’s Introduction to the Symptoms & Signs of Surgical Disease, 2014
Kevin G Burnand, John Black, Steven A Corbett, William EG Thomas, Norman L Browse
A modification of the tourniquet test is to empty the limb as described above and apply direct digital pressure over the upper end of the long saphenous vein while the patient stands up to see if this prevents retrograde filling. This is called the Trendelenburg (tourniquet) test.
Nerve and Root Lesions
Published in John W. Scadding, Nicholas A. Losseff, Clinical Neurology, 2011
Tim Fowler, Nick Losseff, John Scadding
There are sometimes no abnormal signs, although with more severe lesions the thenar muscles are wasted and weak, particularly the abductor pollicis brevis, and some sensory changes may appear in the tips of the thumb, index, middle and ring fingers (Figure 7.1). A tourniquet test may be positive in patients with no signs, when inflation of the cuff around the upper arm rapidly produces similar sensory symptoms in the affected fingers within minutes. In Phalen’s test, forced wrist flexion may provoke similar sensory symptoms.
Beyond thrombocytopaenia, haemorrhage and shock: the expanded dengue syndrome
Published in Pathogens and Global Health, 2018
Senaka Rajapakse, Milanka Wattegama, Praveen Weeratunga, P. Chathurani Sigera, Sumadhya Deepika Fernando
Dengue is caused by a flavivirus transmitted by Aedes mosquitoes. It is prevalent in tropical and subtropical countries, and is currently endemic in South East Asia and the Asia-Pacific Regions. Almost 4 billion people are at risk, and 50–100 million people are infected with dengue each year [1,2]. There are four serotypes of dengue virus, DEN 1–4. Dengue infection has varied presentations, ranging from undifferentiated fever to life threatening haemorrhagic fever (DHF), characterised by plasma leakage and shock syndrome (DSS). Dengue must be considered as a probable diagnosis in patients who live in or recently travelled to a dengue endemic area, presenting with fever and at least two of the following: nausea, vomiting, rash, aches and pains, positive tourniquet test, leukopaenia, or any of a set of defined warning signs (abdominal pain or tenderness, persistent vomiting, clinical fluid accumulation, mucosal bleeding, lethargy, restlessness, hepatomegaly, increase in haematocrit with rapid decrease in platelet count). The latter warning signs may herald the onset of severe dengue, characterised by severe plasma leakage resulting in shock and other manifestations of third space fluid accumulation, and severe bleeding [3].
Dengue: a growing threat requiring vaccine development for disease prevention
Published in Pathogens and Global Health, 2018
Sandra Bos, Gilles Gadea, Philippe Despres
For greater clarity on distinctions between classic dengue fever and dengue hemorrhagic fever or severe dengue, a World Health Organization (WHO) committee developed case classification guidelines in 1974 (WHO 1975), based on studies of disease patterns in children in Thailand in the 1960s, which were subsequently modified and published a number of times. The 1997 guidelines (2nd edition) classified dengue into Dengue Fever (DF), Dengue Hemorrhagic Fever (DHF Grades 1 and 2) and Dengue Severe Syndrome (DHF Grades 3 and 4) (WHO 1997). The case diagnosis for DF emphasized the need for laboratory confirmation. The experience of this classification system has highlighted a number of limitations. This classification is based in particular on clinical data collected from Thai children, which may not be universally representative of dengue fever after its expansion into other tropical regions and older age groups. A range of clinical trials requiring repetition is also needed, which may be difficult for countries with limited resources to implement. The tourniquet test, a measure of capillary fragility and thrombocytopenia for the diagnosis of DHF, is an integral part of the 1997 case definitions. However, the test does not have sufficient sensitivity and specificity to effectively differentiate cases of DF and DHF, and dengue fever from other febrile diseases. For all these reasons, a new classification was established in 2009 by WHO.
Dengue: current state one year before WHO 2010–2020 goals
Published in Acta Clinica Belgica, 2022
K Wellekens, A Betrains, P De Munter, W Peetermans
The clinical course of dengue is broadly divided into three phases: the febrile phase, critical phase, and recovery phase [3]. After the incubation period, the febrile phase starts classically with a sudden onset of high (often saddleback) temperature (≥38.5°C) and shivers. This may be accompanied by malaise, headache, sore throat, conjunctival injection, abdominal pain, vomiting, diarrhea, myalgia, and arthralgia. Some patients develop flushing or a transient rash. Mild hemorrhagic symptoms such as petechiae or mucosal bleeding may occur [3,10–12]. A positive tourniquet test increases the likelihood of dengue [18]. Clinical examination may indicate an enlarged liver. The febrile phase takes about 2–7 days [3].