Septic bursitis typically occurs when the trauma to the knee causes an abrasion, though it is also possible for the infection to be caused by bacteria traveling through the blood from a pre-existing infection site. In approximately 80% of septic cases, the infection is caused by Staphylococcus aureus; other common infections are Streptococcus, Mycobacterium, and Brucella.: p. 359  It is highly unusual for septic bursitis to be caused by anaerobes, fungi, or Gram-negative bacteria.: p. 608  In very rare cases, the infection can be caused by tuberculosis. Diagnosis
There are several types of inflammation that can cause knee pain, including sprains, bursitis, and injuries to the meniscus. A diagnosis of prepatellar bursitis can be made based on a physical examination and the presence of risk factors in the persons medical history; swelling and tenderness at the front of the knee, combined with a profession that requires frequent kneeling, suggest prepatellar bursitis. Swelling of multiple joints along with restricted range of motion may indicate arthritis instead.: p. 608 A physical examination and medical history are generally not enough to distinguish between infectious and non-infectious bursitis; aspiration of the bursal fluid is often required for this, along with a cell culture and Gram stain of the aspirated fluid.: p. 360  Septic prepatellar bursitis may be diagnosed if the fluid is found to have a neutrophil count above 1500 per microliter,: p. 608  a threshold significantly lower than that of septic arthritis (50,000 cells per microliter).: p. 360  A tuberculosis infection can be confirmed using a radiograph of the knee and urinalysis.
Laryngospasm is an uncontrolled or involuntary muscular contraction (spasm) of the vocal folds. The condition typically lasts less than 60 seconds, but in some cases can last 20–30 minutes and causes a partial blocking of breathing in, while breathing out remains easier. It may be triggered when the vocal cords or the area of the trachea below the vocal folds detects the entry of water, mucus, blood, or other substance. It is characterized by stridor or retractions. Some people have frequent laryngospasms, whether awake or asleep. In an ear, nose, and throat practice, it is typically seen in people who have silent reflux disease. It is also a well known, infrequent, but serious perioperative complication.It is likely that more than 10% of drownings involve laryngospasm, but the evidence suggests that it is not usually effective at preventing water from entering the trachea. Signs and symptoms
The main symptom is choking and difficulty or inability to breathe or speak, a feeling of suffocation, which may be followed by hypoxia-induced loss of consciousness. As the airway reopens, breathing may cause a high-pitched sound called stridor. The episode seldom lasts over a couple of minutes before breathing is back to normal. Causes
Various stimuli including asthma, allergies, exercise, stress, and irritants such as smoke, dust, fumes, liquids, and food can trigger laryngospasm.