Wikipedia:Reference desk/Archives/Science/2020 July 23

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July 23

Biochemistry of allergies

Why is it that life threatening allergies involving the respiratory or cardiovascular system is rare compared to Reactions involving the skin and/or digestive tract? Is it just because these areas are more exposed to allergens or is there more protecting the respiratory and cardiovascular systems? Why do many food allergies for example show skin and digestive symptoms but rarely the more life threatening symptoms as an example? Clover345 (talk) 11:43, 23 July 2020 (UTC)

Anaphylaxis, a potentially life-threatening allergic reaction if not timely and appropriately treated, often involves serious respiratory or cardiovascular symptoms. Together these account for most of the lethal cases.  --Lambiam 12:59, 23 July 2020 (UTC)

Also, don't confuse the popular term "allergy", meaning "any adverse reaction to something" and an actual allergy, which is a much more restrictive process in the body. To be an actual honest-to-god allergy, it must be initiated by an immune system response to something. Some things we call allergies may be more properly called things like Irritant contact dermatitis and Food intolerance. Secondly, MANY allergies cause respiratory problems; especially when the mode of the intaking the allergan involves breathing it in. Atopy, a medical term for a specific class of allergic reactions, includes asthma as a common symptom; indeed of the three main components of atopy (eczema, rhinitis, and asthma); two of them are respiratory related (rhinitis is inflammation of the upper respiratory system (nose and sinuses) and asthma is inflammation of the lower respiratory system (lungs)). --Jayron32 15:34, 23 July 2020 (UTC)

But I thought anaphylaxis is quite rare even amongst people with allergies? Clover345 (talk) 16:19, 23 July 2020 (UTC)

The Wikipedia article on anaphylaxis has prevalence figures right in the lead. You're allowed to draw your own conclusions as to the tolerances of a concept like "rareness", but the information necessary to do so is already in the article you were referred to by Lambiam, and rather prominently. --Jayron32 16:21, 23 July 2020 (UTC)

Yes but the article doesn’t answer my original question. Clover345 (talk) 17:10, 23 July 2020 (UTC)

Your original question contains a presupposition that is not currently shown to be true. That is, when you state "Why is it that life threatening allergies involving the respiratory or cardiovascular system is rare compared to Reactions involving the skin and/or digestive tract?" you have not yet established that "life threatening allergies involving the respiratory or cardiovascular system is rare compared to Reactions involving the skin and/or digestive tract.". We can't answer "why" on a concept that is not yet itself shown to be commonly shown to be true. What is even your reason for supposing that? --Jayron32 17:15, 23 July 2020 (UTC)

Ok I shall rephrase the question then - why are cardiovascular and respiratory symptoms less common than symptoms involving other organ systems in people with allergies? Clover345 (talk) 17:34, 23 July 2020 (UTC)

OK, I shall rephrase my question then - Are they? --Jayron32 17:53, 23 July 2020 (UTC)

And before you go digging, Allergic rhinitis is the most common allergy symptom, bar none. Unless you're prepared to argue that respiration doesn't involve the upper respiratory tract, I can't see how an actual honest-to-god respiratory symptom being the most prevalent allergy symptom can do anything but refute your assertion that respiratory symptoms are somehow less prevalent than other symptoms. --Jayron32 17:56, 23 July 2020 (UTC)

That seems to be true which deepens my curiosity. It seems upper respiratory symptoms are more common than lower respiratory symptoms or cardiovascular symptoms. Why is this? Clover345 (talk) 20:40, 23 July 2020 (UTC)

If I were to speculate, it's because allergans have to actually get into the body, so I would suspect the most prevalent allergan responses would be those at the modes of entry to the body: upper respiratory, skin, and digestion. Thus, rhinitis, eczema, and food allergies being among the three most common allergic reactions. --Jayron32 10:35, 24 July 2020 (UTC)

Interesting and that would be my speculation too. Then this raises the question of why people get skin reactions (for examples hives on the body) with food allergies without necessarily getting symptoms elsewhere. In the case of food, mode of entry is the digestive system. Clover345 (talk) 11:32, 24 July 2020 (UTC)

Allergic reactions are type II immune responses. The affected tissues will be a result of the properties of the activated immune cells. Different tissues have different sensitivities in part due to a differing resident immune population, the non immune cells controlled or affected by the immune response and differing innervation by nociceptors. The full answer to your question is scientifically unknown however. PainProf (talk) 14:50, 24 July 2020 (UTC) - This made me realise for reasons unknown we don't describe type 1 immunity vs type 2 in any of the major immunity articles. PainProf (talk) 15:13, 24 July 2020 (UTC)

Inselberges and monadnocks are may not the same thing

I learned from a school textbook of geography that inselberges and monadnocks are not the same thing. I am greatly suprised to see the WP article of inselberg, which says that they are the same thing. Let me illustrate the comparison between inselberges and monadnocks according to the textbook:

Subject	Inselberg	Monadnock
Definition	Hill-looking object located in a desert.	Hill-looking object located in a plain.
Origin	Aerial erosion.	River erosion.
Shape	Slightly circular and steep sides.	Almost circular and not-so-steep sides.

Can someone look into this inselberg–monadnock problem? --Soumya-8974 ^talk _contribs ^subpages 15:28, 23 July 2020 (UTC)

This is one of the many terms that are used somewhat differently in the US compared with UK (and the rest of Europe). A quick glance through the available books on Google Books shows that some works recognise distinct differences, while others view them as synonyms. The place to raise this is at Talk:Inselberg, where you could open a discussion, but read through all the other discussions that look at this particular issue before doing that. Mikenorton (talk) 16:28, 23 July 2020 (UTC)

Coutesy link inselbergs and monadnocks — Preceding unsigned comment added by 31.53.187.190 (talk) 08:32, 24 July 2020 (UTC)

Although "monadnock" redirects to "inselberg", which is the point of the question. Mikenorton (talk) 10:41, 24 July 2020 (UTC)