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.
Other less common causes of chronic ear discharge include 1  : Cancer of the ear canal or tumour in the middle ear. 2  Mastoiditis which is an infection of the mastoid process of the skull which is located behind the external ear. This infection may occur due to otitis media where the infection spreads to the mastoid process.