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 is commonly caused by trapped moisture in the ear canal or by minor injury to the ear canal. Less commonly, otitis externa can occur after otitis media with a ruptured ear drum. Risk factors for otitis externa include: 1  Moisture trapped in the ear canal.2  The condition commonly called swimmer's ear can occur after swimming, bathing, or hot humid weather. 3  Bacteria that cause the infection are able to grow and multiply easily in the warm, dark, moist environment.4  Minor injury or scrape to the ear canal skin. 5  This usually ...ess commonly, otitis externa can occur after otitis media with a ruptured ear drum. Risk factors for otitis externa include: 1  Moisture trapped in the ear canal. 2  The condition commonly called swimmer's ear can occur after swimming, bathing, or hot humid weather.