Erythema multiforme (EM) is a skin reaction that comes from an infection or another trigger. EM is a type of allergic reaction. In most cases, it occurs in response to an infection. In rare cases, it is caused by certain medicines or body-wide (systemic) illness. Infections that may lead to EM include:
The most common causes of sudden (acute) aortic valve regurgitation include: 1  Endocarditis, which is an infection in the heart. 2  Aortic dissection, which means that the inner layer of the aorta separates from the middle layer. 3  Problems with a replacement (artificial) aortic valve.  Trauma to the heart valve or aorta.
Tricuspid regurgitation may also be caused or made worse by problems with the valves on the left side of the heart (mitral or aortic valve) or the left ventricle (which pumps blood from the heart to the rest of the body). It may also be due to any cause of pulmonary hypertension (high pressure in the lung circulation).