How to Photograph a Skin Problem for an Online GP

Skin is one of the things remote consultations do genuinely well — provided the photographs are usable. A clear set of images can settle a diagnosis in minutes. A dark, blurred close-up taken at arm's length in a bathroom can make an experienced dermatologist useless.

The difference between the two is not equipment. Every modern phone camera is more than good enough. It is technique, and it takes about ninety seconds to get right.

The three shots that matter

Send three photographs of the same area, not fifteen of slightly different bits. Volume is not the same as information.

1. The context shot

Taken from roughly a metre away, showing the whole body part — the entire forearm, the whole back, the full leg. This tells me where the problem is and how it is distributed, which is often more diagnostic than what an individual spot looks like.

Distribution is genuinely how skin diagnosis works. A rash on the extensor surfaces of the elbows and knees suggests something quite different from the same-looking rash in the creases. A rash that stops abruptly at a sock line suggests contact. One that follows a single band around one side of the trunk suggests shingles, and that changes the urgency entirely.

This is the shot most people skip, and it is the most useful one.

2. The close-up

From about 20–30cm away, filling the frame with the affected area. This shows the individual lesions — whether they are flat or raised, blistered or scaly, uniform or varied.

Do not go closer than your phone can focus. Nearly every unusable close-up I receive is a photo taken from 5cm, where the camera has given up and focused on nothing at all. If the image looks soft on your screen, it is worse on mine.

3. The scale shot

The same close-up, with something of known size beside the lesion. A ruler if you have one; otherwise a coin, and tell me which. A 5p and a 2p are very different sizes, and "a coin" is not scale.

Size matters more than people expect — for moles especially, where the threshold for concern is often quoted at 6mm, and where a photograph without scale is genuinely uninterpretable.

Light: the single biggest factor

Use daylight. Stand by a window, facing it, with the light falling on the area. Indirect daylight is close to ideal and free.

What to avoid:

• Flash. It flattens texture, blows out redness and creates a bright hotspot exactly where the lesion is. Redness is a diagnostic feature and flash destroys it
• Overhead ceiling light alone. It casts your own shadow onto the area you are photographing
• Bathroom lighting. Warm-tinted bulbs make everything look more inflamed than it is, and fluorescent tubes push colour the other way
• Direct sun. The contrast is too harsh and the shadows too deep

If it is dark outside and cannot wait, use a second light source held to the side rather than the phone's own flash — another phone's torch works well and gives a texture that flash flattens.

Focus, steadiness and the background

Tap the screen on the lesion before you take the picture. Phones focus on whatever is in the middle by default, which is frequently not the thing you care about.

Brace your hand — against a wall, a table edge, your other arm. Slight blur is invisible on a phone screen and obvious on a laptop.

Where you can, put a plain background behind the area: a white towel or a plain sheet. Patterned bedding and busy backgrounds make it noticeably harder to judge colour.

The details people leave out

A photograph tells me what the skin looks like now. It cannot tell me any of the following, and these often matter more:

• How long it has been there, and whether it is spreading, static or fading
• Whether it itches, hurts, burns or feels like nothing at all. Itch versus pain narrows the list substantially
• What it looked like when it started — send an older photo if you have one. Evolution is diagnostic, particularly for moles
• What you have already put on it. This is important and frequently omitted. Steroid creams change the appearance dramatically; so does an antifungal used on something that is not fungal
• Whether you feel unwell with it — fever, aches, feeling generally rough. A rash with systemic symptoms is a different problem from a rash alone
• Any new medication in the preceding weeks, new detergent, new cosmetic, or recent travel

Specific situations

Moles

Include the scale shot without exception, and if you have any older photograph of the same mole — even an incidental holiday snap — send it. Change over time is the most important single feature, and no single image can show it.

Rashes that come and go

Hives in particular can disappear within hours. Photograph it when it is present, even if your appointment is days away. A patient arriving with photographs of a rash that has since gone is in a far stronger position than one describing it from memory.

Anything on the face

Take one photograph straight on and one from each side. Facial conditions are often asymmetric, and asymmetry is informative.

Scalp and hair

Part the hair and hold it apart, and get someone else to take the photo. Self-taken scalp photographs are almost never usable.

Genital and intimate areas

These are legitimate medical photographs and we assess them routinely. Take them in the same way, upload them through the secure system rather than by email or text, and know that they are stored in your medical record under the same confidentiality as everything else.

When a photograph is not enough

I would rather say this plainly than have you pay for a consultation that cannot help.

Some things need to be seen and felt in person. A lesion needing dermoscopy, a lump needing palpation, or anything requiring a biopsy cannot be resolved by photograph, however good. In those cases my job is to recognise it quickly and get you referred, not to guess.

And some things need urgent care rather than a photograph at all. A rash that does not fade when pressed with a glass, particularly with fever or a headache; rapidly spreading redness with severe pain; blistering involving the mouth, eyes or genitals; or any rash with breathing difficulty or facial swelling. Those need 999 or A&E now, not an upload.

The short version

1. Daylight, no flash
2. Three shots: whole area, close-up, close-up with a ruler
3. Tap to focus, brace your hand
4. Plain background
5. Send the history with the images — duration, symptoms, treatments tried
6. Include any older photograph you have

Skin problems are assessed in a standard dermatology consultation, with treatment and a prescription in the same appointment where appropriate.