There are many potential causes of ear blisters, which are fluid-filled sores that can occur on a person's outer ear or inside his ear. Among the most common causes are infections, which can develop because of viruses or bacteria, and skin cancer. A person could also develop ear blisters, particularly those on the outer ear, when he has a severe sunburn. These blisters also sometimes form because of a skin condition such as eczema or psoriasis. Additionally, a nerve condition called Ramsey Hunt syndrome is often first diagnosed because of the presence of blisters on or in a person's ears.
When a person develops blisters on the ears, there is a range of medical conditions that could be causing them. One potential cause is an ear infection. In some cases, the virus or bacterium that caused the ear infection may also cause blisters in the ear. Individuals who are prone to ear infections and suffer from reoccurring bouts may be more likely to develop blisters, but anyone can develop them.
Sometimes a severe sunburn is the cause of an ear blister. Many people fail to apply sunscreen to less noticeable parts of their bodies when they plan to spend time out in the sun, and this includes the ears. Forgetting to apply sunscreen to the ears can prove a mistake, however, as the skin in this area can prove just as susceptible to the sun. When sunburn is the culprit, a person may develop the same redness, discomfort, and blistering he would expect from a sunburn on another part of his body.
Certain skin conditions can also cause blisters to form on or in a person's ears. One of the most common is eczema, which is a skin condition marked by dry, irritated, itchy patches of skin that sometimes bleed. Psoriasis, a skin condition marked by overactive skin cells that cause lesions, can cause this type of blister as well. Additionally, skin cancer is sometimes the problem when a person develops ear blisters.
A condition called Ramsey Hunt syndrome may also cause ear blisters. This syndrome stems from the effects of shingles — a condition that develops because of the same virus that causes chicken pox — on a nerve near a person's ear. It can cause not only blisters in the ear, but also hearing loss. This condition even has the potential to paralyze part of a person's face.