Examples
| Generic Name | Brand Name |
|---|
| diphenhydramine | Benadryl |
| hydroxyzine | Vistaril |
Antihistamines can be taken by mouth or applied directly to the
skin.
How It Works
Antihistamines block histamines—chemicals that cause itching and
other responses to allergic substances.
Why It Is Used
Antihistamines can reduce itching and scratching from
chickenpox (varicella) blisters. Scratching of
blisters can cause skin infection and scars. Some skin infections can be
serious.
How Well It Works
Antihistamines taken by mouth may help prevent you or your child
from scratching the rash and blisters, especially during sleep.
Side Effects
Side effects of antihistamines include:
- Irritability and restlessness (particularly in
children).
- Feeling sleepy and weak.
- Blurred
vision.
- Difficulty passing urine.
- Stomach
pains.
- Dry nose, mouth, and throat.
In very rare cases, antihistamines may cause a person to see and
hear things that are not there (hallucinations), have tremors, or go into a
coma.
See Drug Reference for a full list of side effects. (Drug Reference
is not available in all systems.)
What To Think About
Some experts believe that the chemical histamine is not responsible
for the itching of chickenpox and that the sedating effect of antihistamines is
really what helps the itching.
Some antihistamines, such as Benadryl, can be purchased without a
prescription.
For children, avoid using antihistamines that are applied directly
to the skin, such as diphenhydramine in Caladryl. It is difficult to know how
much of the medicine is being absorbed into their bodies. You may accidentally
apply too much medicine, which can be harmful.
Check with a child's health professional before giving the child
oral antihistamines. Antihistamines have side effects that can cover up signs
of serious complications of chickenpox. Some of these side effects include
feeling sleepy and having hallucinations.
Complete the
new medication information form (PDF)
(What is a PDF document?)
to help you understand this medication.