I've recently been noticing a strange phenomenon of skin-colored bumps, about half the size of a nickel, sometimes in a group of five or so, and sometimes solitary. They itch slightly, though not enough to scratch them to the point of skin breakage like a mosquito bite. There is no "head" nor do they exude anything, and seem also to have no point of entry, like an insect or spider bite.
They usually show up in the morning, and are gone within an hour's time. They only get red when I scratch, too. Typically they're showing up in places along my sides under the arm, behind my knees, and along my back; but the other day my upper lip swelled up with itchiness, too. Same thing, it was gone within an hour. Looked like I got punched, though. They also never seem to show up in the same place twice.
I haven't made any changes to my detergents, and haven't stayed anywhere for any length of time to pick up bugs... Though I was concerned about bed bugs, I don't think these itch enough for that, and the animals in the house don't appear any more itchy than usual. They all have flea medications.
Does this sound at all familiar? I'd like to know how to stop it, and more importantly, if it is contagious or spreadable.