The cause of muscle cramps isn't always known. Muscle cramps may be brought on by many conditions or activities, such as: 1  Exercising, injury, or overuse of muscles. 2  Pregnancy. 3  Cramps may occur because of decreased amounts of minerals, such as calcium and magnesium, especially in the later months of pregnancy.
Causes of Otitis externa. Causes of Otitis externa. Otitis externa is caused by a bacterial or viral infection in the external part of the ear canal. A common bacterial pathogen is Pseudomonas aeruginosa. List of causes of Otitis externa. Otitis externa Causes: Risk Factors.
Otitis externa often results when a change in the normal environment of the ear canal causes the glands lining the canal to enlarge and produce excessive wax. Gradually, the outer skin (epidermis) and the inner skin (dermis) produce excessive fibrous tissue (fibrosis) and the canal becomes narrowed.