Psoriasis: The most common skin disorder that also affects the joints, including the knees, is psoriasis. Although certainly not all patients with psoriasis will develop joint problems, psoriatic arthritis may cause knee pain and swelling. ...Read more.
Definition of accident. 1  1a : an unforeseen and unplanned event or circumstance Their meeting was an accident.b : lack of intention or necessity : chance They met by accident rather than by design.
A casualty is the damage, destruction, or loss of property resulting from an identifiable event that is sudden, unexpected, or unusual. 1  A sudden event is one that is swift, not gradual or progressive. 2  An unexpected event is one that is ordinarily unanticipated and unintended.