The Bright Purple Lesions That Disappear Before the Appointment
Most weeks at Clinique Alpa in Palmers Green throw up a presentation that, on paper, looks textbook and, in the room, turns out to be anything but. This was one of those. An adult patient came in to ask, half-apologetically, about three episodes of bright plum-coloured lesions on the right arm, the first a vivid purple streak running down the forearm, the second and third smaller patches that appeared overnight and faded within 48 hours. The lesions were already partly resolved by the time of the consultation. The pattern was the diagnosis, and the photographs were the evidence.
Why a self-resolving lesion is a diagnostic problem
The natural history of these lesions, on the patient’s own account, is that they appear vividly overnight and fade within 1 to 2 days. That is a problem for the standard NHS pathway. By the time a routine appointment comes around, the skin can be entirely clear, and the dermatologist is left looking at unblemished skin and a worried patient. The diagnostic picture is invisible at the appointment. The diagnostic picture is also the entire reason for the referral.
The deviation today is simple and effective. With the patient’s consent, photographs are taken in the consulting room while the lesion is still partially visible. The photographs become part of the referral. The narrative of the recurrence pattern, the timing, the colour, the satellite spots, the location on the dorsal aspect of the right wrist, are documented in writing. The dermatology team can now answer the diagnostic question even if the skin is clear at the appointment.
What the lesion looked like in clinic
Examination today found a poorly demarcated lesion on the dorsal aspect of the right wrist, plum in colour, fading. There were satellite lesions in the surrounding skin. There was no palpable purpura. There was no mucosal involvement. There were no systemic features today. Recent blood tests in the previous 2 to 3 months were satisfactory, which reduces some differentials but does not eliminate them. Photography captured the colour and the boundary at the moment of the consultation, which is the most useful clinical photograph anyone is likely to get of this presentation.
Clinical anomaly: what was almost missed
First, what was almost missed. The pattern itself is the diagnosis. A lesion that resolves before the appointment can lead to a “see how it goes” plan that misses the dermatology window for the next time, and the time after that. The deviation today is taking photographs in the consultation, in real time, while the lesion is still visible, and using them to anchor the referral. Without the photographs, the next attempt to be seen will repeat the same loop, and a recurring pattern that looks like nothing on the day of the appointment will go unstudied for months.
Second, where the standard NHS pathway would have gone. The standard pathway is to wait for the lesion to be present at the time of appointment. That standard is mismatched with the natural history of this presentation. The deviation here is to refer with photographic evidence and a clear narrative, so the dermatologist has a complete clinical picture even if the skin is clear at review. NICE NG12 frames the urgent suspected cancer dermatology referral pathway. This case does not currently meet those thresholds, but the threshold to escalate is low if the morphology evolves. Topical treatment is offered in the interim for symptomatic relief, but the diagnostic question is the priority. The dermatologist is the right next step.
Third, what differentials were ruled out. Psoriasis was suggested by the patient as a possibility but is reduced by the resolution time-course; psoriasis tends to be more persistent than 48 hours. A simple bruising or coagulation problem was reduced by the recent satisfactory blood profile, but is not formally excluded. Fixed drug eruption was reduced by the absence of any new medication. Urticarial vasculitis and small-vessel cutaneous vasculitis were kept on the differential and named explicitly in the referral letter; both can produce vivid colour, satellite morphology, and recurrence, and both are dermatology calls to make on senior review. Erythema multiforme was considered briefly; the lesions did not have the target morphology, so it was reduced.
The case for clinical photography in the consulting room
Photography of a transient skin lesion in clinic, with consent, is part of the consultation, not an extra. The reasons are practical. Photographs preserve the colour, the boundary, the size relative to a body landmark, and the time of capture. Photographs travel with the referral letter. Photographs allow the dermatologist to see something that has, in all probability, faded by the time of their appointment. Photographs allow the patient to compare future episodes against the documented baseline.
The same logic applies to the patient’s own phone. Patients with recurrent transient lesions can be coached, in clinic, to take their own photographs immediately on noticing. Hold the phone close, use natural light, capture against a plain background, include something for scale, take three or four shots from different angles. The photograph that is taken in the first ten minutes of noticing is the photograph that matters. The diagnostic question is the priority; the rest is logistics.
Differentials worth keeping open in the referral letter
A referral letter that names a single diagnosis is less useful than a referral letter that names the differentials kept open. The reasons are straightforward. The dermatologist is the senior eye, and the senior eye should be presented with the question, not the answer. Naming the differentials at the GP level invites the dermatologist to address each one, rather than confirming or rejecting a single label. The differentials kept open in this referral are urticarial vasculitis, small-vessel cutaneous vasculitis, and fixed drug eruption (despite the negative drug history, because patients sometimes forget over-the-counter or supplement use). The photographs are the anchor.
What the safety net looks like
The safety net is what the patient takes home. Any new mucosal involvement, the inside of the mouth, the eyes, the genitals, return urgently. Any new systemic features, joint pain, fever, blood in the urine, breathlessness, return urgently. Any new bleeding pattern, easy bruising, gum bleeding, return urgently. Any rapid change in the morphology of the lesion, raised, ulcerating, no longer fading within the 1 to 2 day window, return urgently. The threshold to escalate the dermatology referral to a more urgent pathway is low, and the patient should know that.
When to see a same day private GP for a skin lesion that disappears
Several thresholds should move a patient towards a same day private GP appointment rather than a wait-and-see at home. Any lesion that has appeared and disappeared more than once, even if mild. Any vivid colour, particularly purple, deep red, or grey-blue. Any satellite pattern around a main lesion. Any associated new joint, mucosal, or systemic symptoms. The point of the same day appointment is the photograph, the structured history, and the referral with evidence. Without those three things, the next appointment will look at clear skin and ask the patient to come back the next time the lesion appears, and the cycle continues.
What Clinique Alpa offers
Same day access. Live record review. Time to take photographs in the consulting room with consent. Time to write a structured dermatology referral letter that names the differentials kept open, not just a single label. Time to brief the patient on how to take their own phone photographs on the first sight of a future episode. Time to teach the safety net for systemic features. No prescription only medicine names in our public writing, by the rule. What the patient leaves with is a referral, photographs, an interim topical option for symptoms, and a clear plan.
Read more on this theme on our pillar page: Same Day Private GP, Palmers Green.
Clinique Alpa. Same day private GP, Palmers Green, North London.