How long does it take for a red spot to go away?
Well, it depends on what kind of spot, where it is, whether it's been picked at, and so on. But just because there's no straight answer doesn't stop patients from providing one themselves, and then drawing inferences that don't do any good for their prospects or peace of mind.
Many people use the rate at which red spots fade as an index of their overall health, and slow fading means poor healing. The two commonest states for which this is supposed to be a feature are diabetes and old age. Once someone is diagnosed with the former or assigned (by himself or someone else) to the latter, he takes note of a red spot (a scratch, a surgical scar), decides that it's taking too long to go away (has he ever looked before?), and concludes, "I don't heal as well as I used to."
Physicians sometimes reinforce this by telling him that diabetics have "poor healing," from which he deduces, not unreasonably, that any innocent nick can be just around the corner from gangrene. (Most of my diabetic patients seem to heal just as fast as anybody else.)
In this way, persistent redness can imply something about overall state of health. Besides that, redness—which lies right out there on the skin, our territory—can take on specific meaning in several situations we meet every day.
▸ "My acne is starting to scar." Departed inflammatory acne lesions often leave red marks that take some time to fade. How long depends on their depth, state of excoriation, and/or no apparent reason. Some acne patients think of comedones and small papules as more or less normal and don't even come in for treatment until they notice that their spots are taking too long to go away. They refer to this as scarring, by which they don't necessarily mean what we mean by this term, namely permanence.
Acne treatment may fail for many reasons, but one common cause—left out by the promulgators of those accursed algorithms—is despair. The patient sees marks that stay reddish for weeks and picks at them in frustration (which of course perpetuates them). Confronted every day in the mirror with the same two dozen livid marks, she decides that our treatment is a waste of time. Why wouldn't she?
Unless we supplement our treatment, whatever it is, with constant hand holding and reassurance that yes, Virginia, those red spots really do fade over months if they're left utterly alone, and makeup is really okay to use because it won't clog your pores, she'll never get better.
▸ How about some leg makeup? For some reason, red marks take longer to fade the lower down on the body they are. Even when psoriatic plaques flatten, ugly purple splotches persist. These hang around for months, and they may not look improved to patients who aren't explicitly told that indeed they are. Then, of course, there are those with stasis dermatitis who fail to respond to antibiotic therapy for "bilateral cellulitis." After all, the legs still look just as red. …
▸ Red scrotums in the sunset. I often encounter patients, in the office or in online chat rooms, who are convinced that their penises and scrotums are tingly, sensitive, and altogether "too red." One common scenario is this: The patient had balanitis, dermatitis, or perhaps a marathon evening of passion in Bangkok's red-light district. Beset by fear or guilt, he consults a physician, who diagnoses it as (what else?) a fungus.
An endless treatment sequence ensues: antifungal creams, antibacterials, and cortisones. This helps the patient focus on his nether regions and therefore feel all kinds of sensations and notice redness he's quite sure "wasn't there before." Needless to say, he's never stared down there before with this kind of focus until he thought he had an STD or a fungus.
The approach I've found most useful in such cases, once it's clear that there is no active disease, is to tell him to stop absolutely all active remedies, to use only unmedicated moisture lotions, to ignore any tingling as irrelevant, and to look unfailingly up, not down. Eventually, either the redness finally goes away or the patient does, having concluded that whatever the color is really belongs there after all.