Blisters are fluid-filled bumps that look
like bubbles on the skin. You may develop a
blister on your foot when you wear new shoes that rub against your skin or on
your hand when you work in the garden without wearing gloves. Home treatment is
often all that is needed for this type of blister.
Other types of
injuries to the skin that may cause a blister include:
- Burns from exposure to heat, electricity,
chemicals, radiation from the sun, or friction.
Cold injuries from being exposed to cold or freezing
- Some spider bites, such as a bite from a
brown recluse spider. Symptoms of a brown recluse spider bite include reddened
skin followed by a blister that forms at the bite site, pain and itching, and
an open sore with a breakdown of tissue (necrosis) that develops within a few
hours to 3 to 4 days following the bite. This sore may take months to heal.
- Pinching the skin forcefully, like when a finger gets caught in a
drawer. A blood blister may form if tiny blood vessels are damaged.
Infection can cause either a single blister or clusters of
(varicella) is a common
contagious illness that is caused by a type of herpes virus. Chickenpox
blisters begin as red bumps that turn into blisters and then scab over. It is
most contagious from 2 to 3 days before a rash develops until all the blisters
have crusted over.
, often seen in older adults,
is caused by the same virus that causes chickenpox. Shingles blisters look like
chickenpox, but they usually develop in a band on one side of the
Hand-foot-and-mouth disease, another type of viral infection, most often occurs in young children. Symptoms include a rash of small sores or blisters that usually appear on the hands and feet and in the mouth.
, sometimes called fever blisters, are
clusters of small blisters on the lip and outer edge of the mouth. They are
caused by the herpes simplex virus. Cold sore-type blisters that develop in the
genital area may be caused by a
genital herpes infection.
is a bacterial skin infection. Its blisters, which often occur on the face,
burst and become crusty (honey-colored crusts).
- Infected hair
follicles (folliculitis) cause red, tender areas that turn into
blisters at or near the base of strands of hair.
scabies infection, which occurs when mites burrow into
the skin, may cause tiny, itchy blisters that often occur in a thin line or
can cause tiny, itchy blisters anywhere
on the body.
Inflammation may cause skin blisters.
Occasionally a prescription or nonprescription
medicine or ointment can cause blisters. The blisters
may be small or large and usually occur with reddened, itchy skin. If the
blisters are not severe and you do not have other symptoms, stopping the use of
the medicine or ointment may be all that is needed. Blisters may
also occur as a symptom of a toxic reaction to a medicine. This reaction is
Stevens-Johnson syndrome. Blisters that occur with
other signs of illness, such as a fever or chills, may
mean a more serious problem.
Check your symptoms
to decide if and when you should see a doctor.