The risks, plainly. Every treatment described here has side effects, and some carry real risks. Topical steroids thin skin if they are used at the wrong strength on the wrong site for too long, which is why they are prescribed with a site, a strength and a stopping point rather than handed over indefinitely. Light-based and laser treatment can burn, blister and cause pigment change that lasts months, and that risk is higher on deeper skin tones and on recently tanned skin. Any procedure that breaks the skin can bleed, become infected and leave a scar; on the chest, the shoulders and the jawline, scars are more likely to thicken. Several of the medicines used in this speciality require blood tests, and some cannot be taken during pregnancy. We tell you your own risk rather than the average one, and where the honest answer is that a condition is better left alone, that is the advice you will get.
Eight risks
What can go wrong, and how likely it is
Topical steroids — the risk runs in both directions
Used at the wrong strength on the wrong site for too long without review, they thin skin, produce visible vessels and cause a rebound worse than the original problem — most commonly on faces. Used too weakly for too few days out of fear, they leave disease active for years, and chronically inflamed skin also thins and scars. Both failures are avoidable the same way: a strength, a site, a frequency and a written date to stop or come back.
Light and laser treatment — burns and pigment change
Any energy-based treatment can burn and blister, and can cause pigment change lasting months. That risk is meaningfully higher on deeper skin tones and on recently tanned skin, which is why test patches, conservative settings and longer intervals are used — and why the honest answer is sometimes that a light-based treatment is the wrong choice rather than one to be attempted carefully.
Phototherapy — the cumulative risk is the real one
Short-term, burning if the dose advances too fast or a new photosensitising medicine is started mid-course. Long-term, repeated ultraviolet exposure carries a cumulative risk of skin cancer and photoageing. That is why your lifetime number of treatments is recorded across your whole life rather than per course, and why eye protection is not optional.
Cryotherapy — a pale mark that can be permanent
Pigment cells are more sensitive to cold than the tissue around them, so freezing frequently leaves a pale spot. On pale skin this is often barely visible; on medium and deep skin tones it can be obvious and permanent. For a harmless lesion on a visible site that is a poor trade, and it is discussed before rather than after.
Anything that breaks the skin — bleeding, infection, scarring
Biopsies, excisions and cyst removals can bleed, become infected and leave a scar. On the chest, shoulders, upper back and jawline scars are more likely to thicken, and that risk is higher on deeply pigmented skin. Where it applies to you it changes whether an elective procedure is worth doing at all, and it is raised before the procedure.
Systemic medicines — monitoring, interactions and pregnancy
Several medicines in this speciality require blood tests before and during treatment, several interact substantially with common drugs, and several cannot be taken during pregnancy — with one class requiring strict contraception and regular testing throughout. Nobody here is started on one without the monitoring arranged and the pregnancy conversation had properly.
Targeted immune treatments — infection risk and screening
The injectable treatments that have changed what is achievable in severe psoriasis, eczema and hidradenitis work by blocking specific immune signals, and they carry an increased infection risk. They require screening beforehand, including for tuberculosis and hepatitis, and monitoring afterwards. Against that, severe untreated disease carries its own risks. It is a real decision with real trade-offs on both sides.
The risk of doing nothing, which is also a risk
It belongs on this page. A mark that is watched rather than sampled, an acne that is allowed to scar, a scarring alopecia diagnosed a year late, a hidradenitis left to tract — each of those is a decision with a permanent cost, and it is a cost paid entirely by the patient. Declining treatment is often right; declining it without knowing what is being risked is not.
Your half
Eight things you can tell us that reduce the risk
Most complications that are avoidable are avoided by something the patient said rather than something the clinician did.
- Tell us every medicine you take, including anything bought over a counter, any supplement, and anything started by another doctor since your last visit.
- Tell us if you are pregnant, might be, or are trying to become pregnant — it changes several treatments here.
- Tell us if you or your family form thickened or keloid scars, before any procedure rather than after one.
- Tell us if you have fainted at needles or during a procedure before. We will do it lying down and nobody will comment.
- Do not stop a prescribed blood thinner before a procedure unless the doctor who prescribed it has told you to.
- No sunbeds, and no fresh tan, in the fortnight before any light-based treatment or skin examination.
- Ask for a chaperone at any examination. You only have to say the word, and it is an entirely ordinary request.
- Telephone us if something is worse rather than better after a procedure, instead of waiting for the review appointment.
Questions
Safety — the questions we are asked most
Which is the riskiest thing you do here?
In terms of the frequency of a lasting consequence, it is probably cryotherapy on deeply pigmented skin, because a permanent pale mark on a visible site is common enough to matter and is often accepted without discussion. In terms of severity, it is a systemic medicine started without proper monitoring or without the pregnancy conversation — which is why neither happens here.
Are steroid creams safe?
At the right strength, on the right site, for a defined period, with a review — yes, and they are the treatment that gets most eczema under control. The problem we see far more often than thinning is the opposite: something far too weak, used for three days, abandoned, repeated for years while the disease stays active.
Can I have laser treatment on brown skin?
Some treatments, at appropriate settings, with test patches and longer intervals. Others are not suitable at all. Melanin absorbs the energy these devices deliver, which raises the risk of burns and lasting pigment change. Anybody who does not raise that with you before treating is not the right person to be operating the device.
What happens if something goes wrong after a procedure?
Telephone us. Increasing pain from day three onwards, spreading redness, heat, swelling, discharge or fever is how an infection presents and it wants a call rather than a wait. We would far rather see you early about something that turns out to be ordinary healing.
Do you ever decline to treat?
Regularly, and it is a normal outcome of an appointment rather than a failure of one. A harmless lesion on a keloid-prone site, a light-based treatment on skin where the risk outweighs the benefit, a systemic medicine in somebody who cannot attend for the blood tests — in each case the honest answer is no, and it costs exactly the same as yes.
This page is not medical advice, and it is not a diagnosis. Nothing on this website is medical advice for you in particular, and it is not a diagnosis. These pages describe conditions in general terms so that you arrive knowing what the questions are — they cannot tell you which condition you have, because that requires somebody to look at your skin, feel it, ask you a hundred questions and frequently take a sample of it. Two conditions on this website can look identical in a photograph and need opposite treatments. If something on your skin is new, changing, painful or not healing, the useful next step is an appointment rather than more reading.
A named diagnosis and a written plan you leave holding
Book an appointment
Pick a physician and a time from the calendar — it shows only the hours each of them genuinely has free. A new patient appointment is thirty minutes, a full skin examination forty-five, and you leave with a named diagnosis written down. If something on your skin has changed, telephone instead and say that word: it is triaged differently.