3. An infection of the bursa
Not all forms of bursitis are caused by injury or pressure on the knees, but in 20% of cases, irritation or pain in the bursa results from infections. This is most frequent in the summer months when the prepatellar bursa can become infected from a cut, a scratch or a bite. It isn’t only a cut or a scrape that can introduce the infection, known as septic bursitis, but an underlying condition can often cause the condition. When the immune system is not working effectively, bursitis is more likely to occur.
This can happen if someone is suffering from HIV, lupus, cardio-pulmonary disease, alcoholism or diabetes. When the system is overworked or if an illness is keeping the immune system from functioning, internal infections are more likely to happen and bursitis can result. Like all internal infections, septic bursitis must be treated immediately to prevent the infection from spreading to other areas of the body.