Diseases & Conditions
A raised oval or round collection of ﬂuid within or beneath the outer layer of the skin. Blisters larger than a half inch in diameter are sometimes called “bullae”; small blisters are also called vesicles. Blisters that have been inadvertently pierced may be susceptible to infection, which is indicated by redness, swelling, an odor, or cloudy ﬂuid.
A blister appears after minor skin damage when serum leaks from blood vessels in underlying skin. The serum is usually sterile, and the blister provides valuable protection to the damaged tissue. Blisters often appear after BURNS, SUNBURN, or friction (such as damage to the heel from wearing a poorly ﬁtting shoe).
In addition, small blisters develop in the early stages of many viral infections, including CHICKEN POX, SHINGLES, and HERPES simplex; these blisters contain infectious particles capable of spreading the infection.
A blister should not be disturbed but should be left to heal on its own. It may be pierced at the edge using a sterile needle, allowing the ﬂuid to slowly seep out. However, a blister should never be unroofed, as the top ﬂap of skin protects against infection. Children with large, troublesome, or unexplained blisters should be seen by a doctor.
To protect the blister, a moleskin pad (available at drug stores) can be cut to resemble a doughnut, with the blister in the middle; the moleskin will absorb the friction of daily activity.
If a blister inadvertently bursts or gets pierced, the skin should not be removed over the top. Left intact even after the blister has drained, this skin ﬂap will act as a type of bandage; it will eventually harden and fall off by itself.
Triple topical antibiotics (such as Neosporin) may eliminate bacterial contamination, but iodine or camphor-phenol will slow down healing.
Children should always wear socks with shoes, and gloves on hands when using tools. Feet should be powdered when wearing new shoes. Children at risk for getting a blister on the foot should try coating blister-prone areas with petroleum jelly or diaper rash ointment (such as A&D ointment) to cut down friction.
Experts do not agree on the type of sock that best protects against blisters, but current research suggests that acrylic spun ﬁbers may be better than cotton in the presence of water. Wearing two sets of different sock materials on each foot with properly ﬁtted shoes helps prevent blistering.