Eeuuuuw -- what are these things on my skin?

M.A. of Reader:

I was looking at a mole on my arm recently and began to wonder what they are and what causes them.

-- L.B. of Poway

Hey, Matt:

What's behind the phenomenon of skin tags? Since turning 40, these very little strange growths have been happening on my body. Can I grow another appendage? Why is it happening now? My doc says it's because I'm fat.

-- GC in LJ

Ahhh, yes, the boomers are now deep into the ugly-skin-lesion years, aren't they. You used to play softball, knit socks for third-world refugees, study Spanish in night school. Now all your time is spent in contortions in front of a mirror, trying to get a good look at those crusty brown patches, hairy lumps, scary red vein-y things that you're sure weren't there last week. Well, GC, according to my copy of Skin Lesions for Dummies, skin tags are small teardrop-shaped pouches of cells that tend to appear in midlife, serve no purpose, pose no threat, and have no known cause. People who've gained weight seem more prone to them. Why? Who knows. Losing weight won't make them go away. They tend to appear in skin folds (underarms, eyelids, groin). They can be lasered off, frozen off, or cut off if you don't like them, but you can also just ignore them. And please, GC, make sure you tell your doctor that you came to me for a second opinion and that I backed up the original diagnosis. He/She will be pleased, I'm sure.

Moles are a little more complicated. They're basically skin bumps that are with you from birth. They serve no purpose, and for the most part have no real definable origin. Some moles on the trunk or abdomen might be what's known as supernumerary nipples. At an early stage, pre-birth, we all develop what's called a milk line-- two vertical rows of rudimentary nipples like you might see on a dog or cat. Ordinarily, only two remain by the time we're born. But sometimes one or more additional nipples will be left in the form of a "mole." In the case of moles, any time spent examining them for changes is time well spent. At least that's what my lawyers tell me to say.