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 common causes include a foreign body (like a grass seed), parasites like ear mites or ticks, excess hair or mats in or around the ears, allergies, or excess wax production. Most cases are confined to the external portion of the ear canal and/or the ear flap (pinna) âand are termed otitis externa. Otitis externa occasionally advances into the middle ear (otitis media), and even more rarely into the inner ear (otitis interna).