Spring is in the air....

[bsdgeek]

I took the red pill.

[Dr Mordrid]

Originally posted by The PIT
Also some people like looking for allergies and illness like some of my family.
I reckon some of the problem is doctors and the other pollution.

Don't blame the physician for being the messenger of bad news. The causes are not as simple as you presume. There are 4 types of allergic response;

1. Immediate Hypersensitivities. Most often these act quickly and are mediated by IgE class antibodies after a benign first exposure. These antibodies are found on MAST cells, which are geared to react to allergens when they're detected by the antibodies. It's the degree of this reaction that causes problems.

When the MAST cells react to an allergen histamines and leukotrienes are released, which causes a local anaphylacic response: swelling, redness, and itching in the surrounding tissues.

If the MAST cells over-react you end up with a much stronger reaction to allergens than "normal"; often leading to the swelling shut of nasal and/or bronchial airways, excessive mucous production, reddish discoloration due to increased local blood flow etc.

Examples: hay fever, asthma and hives.

2. Antibody-Mediated Cytotoxicity. This is a form of autoimmune disorder. It's a form of cell damage caused by antibodies directed against cell surface antigens.

Example: Myesthemia Gravis.

3. Immune Complex Disorders. Caused by the deposit in the tissues of antigens and their antibodies.

Example: SLE (Lupus).

4. Cell-Mediated Hypersensitivities. These reactions are mediated by CD4+ T cells, which are part of the immune system. There are two types: intrinsic and extrinsic.

Example (intrinsic): Rheumatoid arthritis, multiple sclerosis, type-1 diabetes and other auto-immune disorders.

Example (extrinsic): Catechols (the toxins in poison ivy/oak/sumac), nickle (the metal), chemical sensitivites and certain dyes.

A genetic predisposition contributes a lot to these and environmental factors can make them worse...but in the end its largely an inherited hair-trigger response of these otherwise normal functions.

Dr. Mordrid

[Tjalfe]

Did people have these kind of allergies back in the old days, or is it something which is happening only in "advanced" societies?

[Sethos]

Originally posted by Helevitia
I am the only person I know that doesn't have allergies. Usually if something is bothering my nostrils, I sneeze and the problem goes away.

Dave

Oh to be so lucky...

~Sethos

[Dr Mordrid]

Did people have these kind of allergies back in the old days, or is it something which is happening only in "advanced" societies?

Yes they did. The difference is that many of these conditions caused people be less sucessful at reproducing in the past, which limited the percentage of the populace that had the genetic predispositions that contribute strongly to allergies.

Still, environmental factors can make marginally or asymptomatic people miserable. The soot from diesel engines is one environmental factor that strongly affects the rates of asthma (25% of children in some central cities). Cell-Mediated Hypersensitivity (extrinsic) is another environmentally influenced allergy mechanism.

Another factor making things worse vs. earlier days: today most homes are carpeted and our furnishings are upholstered; both of which are a perfect breeding ground for dust mites. Their droppings (along with the fungi that grow on them) become very easily airborn, making up a very high percentage the total volume of house dust in most locales, and are among the strongest of allergens in terms of the MAST cells response to them. Once airborn they can remain suspended for 20-30 minutes.

Because of the affect of dust mite droppings on the allergic response one of the first things an allergist will tell a patient is to get rid of the carpeting in favor of tile, wood or synthetic flooring (at least in the bedroom), put on plastic matress covers and to use synthetic materials in their pillows.

What you do with your furniture is another matter since wives are usually involved

Dr. Mordrid

[Tjalfe]

Thanks for the info.. never having had allergies of any sort, I never looked into it... and damn.. those must be some serious allergies they had in the days which influenced their success in breeding!

[Dr Mordrid]

People die from MS, diabetes, MG etc. etc.....right? A lot of people also die from "anaphylaxis"....which is a strong triggering of the allergic responses. Bee stings, various food allergies (including nuts & seafoods), latex sensitivities, drug allergies etc. are perfect examples of allergies that can cause death.

Most estimates say that ~57,000 people in the US experience anaphylaxis each year, with some estimates running as high as 82,000.

Also remember that in the US alone over 5,000 people died last year from asthma alone. In years past it was much worse because of the lack of effective treatments for asthma and allergies.

Many of the past allergy related deaths were written off to other causes. One example is that those dying from asthma often had a cause of death recorded as "pneumonia", so checking the old medical records is often misleading.

Another problem is that people getting respiratory infections often have their symptoms made worse by the stress triggering their asthma. Often these deaths get reported as "flu" or "pneumonia" induced, but the asthma is very often a major contributing factor....even if it isn't recorded as such.

Dr. Mordrid

[Tjalfe]

Thanks again .. learning new stuff is always good!