This is part of our House MD Project series.
Click here to read the connection to the episode (spoiler alert!)
Dr. Chase and Sister Augustine on the “Damned If You Do” episode
Danger level: Medium
What is it?
Allergy is an abnormal response of our body’s immune system. The immune system contains types of cells that are supposed to fight infections in our bodies. That is, it’s designed to attack germs, viruses, and other harmful critters.
When you have an allergy to something, that something is usually harmless – like pollen, mold, animal dander. Yet the body recognizes it as something bad and starts the whole attacking process.
Who gets it?
Not everyone gets allergies. The tendency to develop an allergy is tied to several factors:
- Heredity – Allergic conditions tend to run in families. If neither one of your parents has allergies, you have about 15% chances of being allergic. If one of them is allergic, your risk rises to 30%. If both – 60%.
- Environment – It’s not enough to have a tendency to allergic reactions. You have to be exposed to the material you’re allergic to.
What causes it?
When you’re exposed to something you’re allergic to (called an allergen), the body produces antibodies. These are molecules designed to attack foreign intruders. There are all sorts of antibodies. The ones in an allergic reaction are of the IgE type.
Those IgE antibodies attach to a type of cells called mast cells. They, in turn, release chemicals (like histamine) into the blood that cause the symptoms.
This video shows this nicely (although a little more elaborately) -
How does it feel?
When you’re allergic to something you inhaled or something that touches your skin, common reactions include -
- Itchy, watery eyes
- A runny nose and sneezing
- Rashes
- Feeling tired or ill
When you’re allergic to a certain food you may feel stomach cramps, vomit or have diarrhea. When you’re allergic to an insect bite, you may see local swelling, redness or pain.
Anaphylaxis is a severe reaction as part of an allergy which is also life threatening. It includes reactions in your skin, respiratory system (you may choke), digestive system, your heart and blood vessels and your nervous system. You get the picture…
On that episode of house, the nun had an anaphylaxis when staying in the clean room.
Copper allergy / IUD allergy
In the House episode, the nun had an allergy to copper, and specifically to an IUD device implanted in her.
Problem is – the device was implanted years before. So how come she wasn’t allergic till now?
Allergies can be tricky that way. People can have a first exposure to an allergen, which causes the reaction described above. From then on, there’s a period of sensitization, which can take from months to years, after which another exposure to the allergen can cause an allergic reaction.
In the House episode, the nun was first exposed to copper in her IUD, but a reaction didn’t happen until she was exposed to copper again – this time through contact with copper cookware she washed.
How is it discovered?
When the doctor suspects you have an allergy, they can run a skin test. In it, an extract of an allergen is applied to your skin (after scratching your skin or pricking it to expose it to the material. That’s why it’s called a prick test). If your skin reacts to the allergen it will show as an inflammation in that area.
Skin prick test. Photo by Lindspetrol
Another option is a blood test – which can identify IgE’s specific to certain allergens.
How is it treated?
There’s no cure for allergies, but there are medications that can ease the symptoms. Covering all of them is beyond the scope of this article. Their names contain antihistamines, corticosteroids, and others.
Besides that, the treatment for anaphylaxis (see above) is epinephrine, which can save your life. Sometimes people with tendencies to severe reactions find themselves with no hospital in their vicinity. For that matter an epinephrine pen was invented, which you carry with you in your pocket and can save your life.
The bottom line – How do I avoid it?
Once you know you’re allergic to something, avoiding that allergen can prevent the symptoms.
What next?
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Related posts:
- Colchicine Overdose (As Seen on House MD)
- Ornithine Transcarbamylase Deficiency– What If You Couldn’t Eat Steaks? (As Seen on House MD)
- Common Variable Immunodeficiency (CVID)–When a Cold Can Threaten Your Life (As Seen on House MD)
- Wilson Disease – The Return (As Seen on House MD)
- Naphthalene Poisoning – When Mothballs Kill More Than Just Moths (As Seen on House MD)
April 27th, 2010 at 7:36 pm
This is the great blog, I'm reading them for a while, thanks for the new posts!