Aha, now you know how my chin feels and why I wore a beard from the learly 70's to the early 90's.

On a practical front, there are many patents issued for "razor burn" formulations and a multitude of products to treat it. For the ordinary red dots form of razor burn any number of cosmetic products offer some relief. The one's with a high Aloe content (read the contents part of the label) and/or alpha hydroxy acids (e.g. lactic acid, propionic acid) probably work best. If tiny little white superficial pimples form a benzoyl peroxide ointment (e.g. Clearasil) works best.

Razor burn is a combination of mechanical irritation of what is called the pilosebacous unit (the combination of the hair follicle and the attached sebaceous gland). When the hair is tugged, the sebaceous gland is stimulated to produce more sebum. In most cases the tunnel through which the hair shaft passes (the infundibulum) gets inflammed and because of the inflammation, super sensitive. A mild topical anti-inflammatory (like Aloe) helps releave this. In some cases, skin bacteria (staphylcocci) grow a little faster in this irritated epidermis. The benzoyl peroxide kills the staph. You may also want to minimize the number of bacteria on your razor by soaking it for 15 minutes or so after use in rubbing alcohol (one of the few things rubbing alcohol is good for). Use a shaving cream or gel designed to prevent razor burn. Afterwards, Chanel's "Allure - Homme" aftershave cream works about the best.

The best animal model for razor burn is the guinea pig which has a skin structure kind of like human chin skin.

If you have sensitive skin, absolutely avoid shaving plus depiliants (like Nare).

Yes there is "accomodation" with repeated shaving. This is due to a thickening of the outer portion of the skin (the epidermis) particularly the epidermis that lines the follicular infundibulum. However, not all people develope accomodation. My impression is that blonds have more trouble accomodating but I have seen a dozen or so dark-haired individuals who have terrible razor burn.

Why there are differences between the sides of men's faces & jowls and their chins I do not know. Why women's legs are less susceptible to razor burn than their nether regions I do not know. And why there is so much person to person variation in razor burn I also do not know.

Probably the best high Aloe content lotion on the market is "Aloe Re-leaf Body Lotion" which is sold mostly in the Rio Grande valley. Unfortunately they are not marketed nationally. They have a web site (www.aloereleaf.com) and when they have excess production you can direct purchase from them.

Also good is "Dermaide" cream manufactured by Hagstrom in Palos Hill, Ill. This is even harder to get than "Aloe Re-leaf". Unfortunately, "Dermaide" has a relatively ancient vehicle formula. This means that although it is a vanishing cream, it is formulated with lanolin and mineral oil and shorter chain alcohols. Therefore it is oilier than the "Aloe Re-leaf".

Hope this will be of help. Yours from the fascinating world of skin irritation. Don't try this on your guinea pig without a valid Animal Care and Utilization Committee approval or you may be in violation of Federal Law.