House Wiki

Asthma is an autoimmune disease related to allergies, but also has a genetic component as it tends to run in families. In addition to normal allergy symptoms, asthmatic patients suffer increased histamine production in the lungs that constrict the bronchial tubes without the same complications as anaphylactic shock. However, severe asthma can be life threatening, and unlike most persons with severe allergies, asthma sufferers are usually sensitive to a large number of environmental allergens, such as pollen, dust and animal dander.

Steroid puffers are generally the treatment of choice as they prevent the buildup of histamines on an ongoing basis and prevent attacks. They are also useful when attacks become severe. In addition, it is recommended that sufferers stay away from sources of allergens whenever possible.

House's exposure to asthma patients is generally in the clinic. He has little patience for patients who ignore the seriousness of their condition or the necessity to use steroids to control it.

Asthma Mom: "I'm worried about the effect of such strong drugs on my child."
House: "Well, your doctor probably balanced the dangers of steroids against the dangers of not breathing.... Never mind, if you don't trust steroids, you shouldn't trust doctors."
— Pilot

In Joy to the World, House is attempting to be nice to patients to win a bet with Wilson when he suspects that an asthma patient is not using her inhaler properly. His suspicions are confirmed and we see the patient leaving the clinic in a huff.

Asthma at Wikipedia

Asthma at Mayo Clinic