Influenza-like illness (ILI), also known as flu-like syndrome or flu-like symptoms, is a medical diagnosis of possible influenza or other illness causing a set of common symptoms. These include fever, shivering, chills, malaise, dry cough, loss of appetite, body aches, and nausea, sneezing typically in connection with a sudden onset of illness. In most cases, the symptoms are caused by cytokines released by immune system activation, and are thus relatively non-specific. Common causes of ILI include the common cold and influenza, which tends to be less common but more severe than the common cold. Less common causes include side effects of many drugs and manifestations of many other diseases. Definition
The term ILI can be used casually, but when used in the surveillance of influenza cases, can have a strict definition. The World Health Organization defines an illness as an ILI if the patient has a fever greater than or equal to 38 C° and a cough, which began in the last 10 days. If the patient requires hospitalisation, the illness is classified instead as a severe acute respiratory infection (SARI). Other organisations may have different definitions. For instance, the CDC defines it as a 100 °F (38 °C) fever or greater, and a cough or sore throat. Causes
The causes of influenza-like illness range from benign self-limited illnesses such as gastroenteritis, rhinoviral disease, and influenza, to severe, sometimes life-threatening, diseases such as meningitis, sepsis, and leukemia. Influenza
Technically, any clinical diagnosis of influenza is a diagnosis of ILI, not of influenza.
However, it has been suggested that bone demineralization is most pronounced in young people (25–44 years of age) and one 1987 study of institutionalized people found that the rate of osteomalacia in the ones taking anticonvulsants—one out of nineteen individuals taking an anticonvulsant (vs. none among the thirty-seven people taking none) —was similar to that expected in elderly people. The authors speculated that this was due to improvements in diet, sun exposure and exercise in response to earlier findings, and/or that this was because it was sunnier in London than in the Northern European countries which had earlier reported this effect. In any case, the use of more than one anticonvulsant has been associated with an increased prevalence of bone disease in institutionalized epilepsy patients versus institutionalized people who did not have epilepsy. Likewise, postmenopausal women taking anticonvulsants have a greater risk of fracture than their drug-naive counterparts.Anticonvulsants affect the bones in many ways. They cause hypophosphatemia, hypocalcemia, low Vitamin D levels, and increased parathyroid hormone. Anticonvulsants also contribute to the increased rate of fractures by causing somnolence, ataxia, and tremor which would cause gait disturbance, further increasing the risk of fractures on top of the increase due to seizures and the restrictions on activity placed on epileptic people. Increased fracture rate has also been reported for carbamazepine, valproate and clonazepam. The risk of fractures is higher for people taking enzyme-inducing anticonvulsants than for people taking non-enzyme-inducing anticonvulsants.