What is prickly heat?
Prickly heat is a skin rash caused by sweat trapped in the skin.
Normally, sweat travels to the surface of the skin through tiny ducts. If the ducts
become narrowed or clogged, the sweat is trapped in the skin. This can cause
redness, itching, and small blisters. The rash often appears on the torso and
thighs, especially where skin touches skin. Prickly heat tends to be more common in
hot, humid climates.
What causes prickly heat?
The condition is caused by narrowed or clogged sweat ducts. This
may be because of things that cause sweating, such as:
Hot, humid weather
A lot of physical activity
Illness with fever
Tight or warm clothing
Medicine patches that stick to the skin
Health conditions that cause extra sweating
It may also be from:
Who is at risk for prickly heat?
You are more at risk for prickly heat if you sweat a lot, but it
is more common in children.
What are the symptoms of prickly heat?
Symptoms can occur a bit differently in each person. They can
The symptoms of prickly heat can be like other health conditions.
Make sure to see your healthcare provider for a diagnosis.
How is prickly heat diagnosed?
Your healthcare provider will ask about your symptoms and health
history. He or she will give you a physical exam. The physical exam will include
looking closely at your skin.
If you have severe symptoms, your healthcare provider may do a
skin biopsy. He or she will remove a small piece of skin to send to a lab.
How is prickly heat treated?
Treatment will depend on your symptoms, your age, and your general
health. It will also depend on how severe the condition is.
The rash usually goes away on its own when sweating is prevented.
You can do this by:
Keeping your skin cool and dry
Wearing lightweight, loose clothing
Wearing fabric that lets air get to the skin, such as
Removing bandages or patches
Other treatment may include:
Using a gentle exfoliator in the bath or shower
Corticosteroid cream or lotion to help reduce itching and
Antibiotic cream or lotion if bacteria is part of the
Talk with your healthcare providers about the risks, benefits, and
possible side effects of all medicines.
What are possible complications of prickly heat?
In rare cases, blocked ducts may cause damage to sweat glands.
This is called miliaria profunda. The sweat glands stop working (anhidrosis). This
causes problems with the body cooling itself normally with sweat. You can then be
more easily overheated (hyperthermia).
Can prickly heat be prevented?
You can help prevent the problem by:
Staying in cool environments
Wearing lightweight, loose clothing
Taking other steps to prevent extra sweating
When should I call my healthcare provider?
Call the healthcare provider if you have:
Key points about prickly heat
Prickly heat is a skin rash caused by sweat trapped in the
skin. It tends to be more common in hot, humid climates.
Symptoms include redness, itching, and small blisters.
The condition is caused by narrowed or clogged sweat ducts.
This may be from things that cause sweating, such as hot, humid weather or
The rash usually goes away on its own when sweating is
prevented. You can do this by keeping your skin cool and dry.
Treatment may also include corticosteroid cream or lotion to
help reduce itching and inflammation.
Tips to help you get the most from a visit to your healthcare
Know the reason for your visit and what you want to
Before your visit, write down questions you want
Bring someone with you to help you ask questions and
remember what your provider tells you.
At the visit, write down the name of a new diagnosis, and
any new medicines, treatments, or tests. Also write down any new instructions
your provider gives you.
Know why a new medicine or treatment is prescribed, and how
it will help you. Also know what the side effects are.
Ask if your condition can be treated in other ways.
Know why a test or procedure is recommended and what the
results could mean.
Know what to expect if you do not take the medicine or have
the test or procedure.
If you have a follow-up appointment, write down the date,
time, and purpose for that visit.
Know how you can contact your provider if you have