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.
Causes of otitis externa can include: 1  a bacterial infection â usually by bacteria called Pseudomonas aeruginosa or Staphylococcus aureus. 2  seborrhoeic dermatitis â a common skin condition where the areas of your skin that are naturally greasy become irritated and inflamed, which can sometimes affect the ears.auses of otitis externa can include: 1  a bacterial infection â usually by bacteria called Pseudomonas aeruginosa or Staphylococcus aureus. 2  seborrhoeic dermatitis â a common skin condition where the areas of your skin that are naturally greasy become irritated and inflamed, which can sometimes affect the ears.