A useful description covers five things: where it is, what it looks like, when it started, how it has changed, and what it feels like. Describing those without offering a theory about the cause gives a clinician far more to work with than any guess you could make.
This page describes how dermatology consultations generally work in the United Kingdom. Arrangements differ from one country to another.
Most people arrive with one word, and it is usually rash. It is a reasonable word and it conveys almost nothing: it tells a clinician that something visible is happening on your skin, which they can already see.
What follows is not a script. It sets out the small number of things clinicians reach for, in the order they tend to ask, so that you can describe your skin rather than search for words while somebody waits.
Five things are worth being able to describe: where it is, what it looks like, when it started, how it feels, and what has already been done. Cover those five and a clinician has almost everything a consultation needs from you.
Where is it, and where is it not?
Location does an enormous amount of work in dermatology, and describing where something is absent matters as much as describing where it is present. A patch on both elbows suggests something different from the same patch on one forearm; something on sun-exposed skin only is a different proposition from something under clothing.
Describe the pattern rather than a single spot. Is it on both sides of the body, roughly symmetrically, or on one side? Is it in creases and folds, or on the outer surfaces? Did it start in one place and spread, and if so in which direction?
If it appeared somewhere and then somewhere else, say so, and say which came first. That sequence is frequently the most informative sentence in the whole consultation.
What does it look like?
You do not need clinical vocabulary to describe appearance, and inventing it usually goes wrong. Ordinary words work, provided they are specific.
Flat or raised is the first distinction, and clinicians make it constantly. Can you feel it with your eyes closed, or is the skin smooth where the colour has changed? Then the surface: smooth, scaly, crusted, blistered, weeping? Edges next. Are they sharp enough that you could draw round them, or does the area fade gradually into normal skin? Describe the colour too, and whether it is even or varies across the patch.
Size is best given by comparison to something ordinary rather than in units. Describe whether individual spots are separate or running together.
When did it start, and what has it done since?
Approximate is fine. What matters is anchoring it to something: after a holiday, during a cold snap, around the time you changed jobs. That kind of anchor is more reliable than a date pulled from memory and it carries context with it.
Then the trajectory. Has it grown, spread, faded, stayed the same? Does it come and go, and if so how long does a single episode last? Something that clears completely between episodes is a different animal from something that never quite goes.
Anything that preceded it belongs here too: an illness, a new medicine, a new product, an insect bite, a period of unusual stress. You are not being asked to identify the cause, only to report what happened nearby in time.
What does it feel like?
Sensation gets left out because it feels subjective, and it is one of the more discriminating things you can describe.
Itch, burning, stinging, soreness, tightness, numbness and pain are not interchangeable. Whether it is worse at night, worse after a shower, worse when you are warm, is worth mentioning. So is whether scratching relieves it or makes it worse, and whether it wakes you.
That last point carries weight beyond the symptom itself. Sleep disruption is one of the ways clinicians gauge how much a skin condition is actually costing somebody, and it correlates poorly with how dramatic the skin looks.
What have you already done about it?
Everything, including the things that seem too minor to mention and the things you would rather not admit to. A cream from a pharmacy, something a relative recommended, a product bought after reading about it, an old prescription found in a drawer.
Each of those is a small experiment, and the result matters whichever way it went. Something that helped narrows the field; something that made it worse narrows it differently. A clinician who does not know what has been tried may suggest exactly what has already failed.
Bring the actual containers rather than the names, since the label on the back is the part that carries the information.
What is worth leaving out?
Your theory, mostly, or at least your certainty about it. Mentioning a worry is useful and sensible, and clinicians would rather hear it than have it sit unspoken. Describing it as a conclusion is different, because a confident name spoken early can quietly narrow what everybody in the room is looking at.
Report what you observed. Name the worry plainly, as a worry. Then let the person who can examine your skin do the part that requires examining it.
Common questions
Why is saying 'I have a rash' not enough?
Because rash covers an enormous range of quite different things. It tells a clinician that something is visible on your skin and almost nothing else. Adding where it is, how long it has been there and whether it itches turns a word into information they can act on.
Should I try to name what I think it is?
You can mention it, but say it as a worry rather than a conclusion. A confident wrong name can anchor the conversation, and clinicians work from what they observe and what you describe. Your observations are genuinely valuable; your diagnosis is the part they can supply.
How precise do I need to be about dates?
An approximate month tied to something memorable is usually plenty. Nobody expects a diary entry. The difference that matters is between a while ago and around the end of a particular month, because the second lets a clinician relate it to other events.
What if it looks different every time I check?
That is itself worth saying, and clearly. A condition that changes hour by hour behaves quite differently from one that stays put, and clinicians ask how long an individual spot lasts for exactly that reason. Variability is information rather than an obstacle.
Does it help to describe how it feels?
Considerably. Itching, burning, stinging, soreness and numbness are different sensations that point in different directions, and people often leave them out because they seem subjective. They are part of the clinical picture, not an aside.
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