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Dr. Chrysoula I. Liakou MD, PhD
- Treated online: Yes, usually. Most everyday rashes are identified from clear photos plus video and treated with the cream, antihistamine, antifungal or antiviral that matches the cause; a non-blanching rash, a rash with high fever, blistering or peeling, or facial swelling needs emergency or in-person care.
- What it is: a visible change in the skin from inflammation, infection, allergy or bleeding; in adults the commonest causes are eczema, contact dermatitis, hives, fungal infection, viral rashes, heat rash and drug reactions, each with a recognisable pattern.
- The glass test: press a clear glass firmly against the rash; spots that stay visible through the glass are not fading, which with fever, drowsiness, headache or a stiff neck can mean meningococcal infection: call 112.
- Right cream: a steroid cream helps eczema, worsens fungal infections and does nothing for hives, so naming the rash matters more than any product; a rash that has outlasted 2 weeks of pharmacy treatment is probably the wrong diagnosis.
- Darker skin: redness is harder to see on brown or black skin, where rashes look purple, grey or darker than surrounding skin; check paler areas such as the palms, soles and inside of the forearm, and photograph in daylight.
- Emergency: call 112 for a rash that does not fade under a glass, a rash with high fever and feeling very unwell, rapidly spreading painful redness, widespread blistering or peeling, or swelling of the lips, tongue or throat.
Press a clear glass firmly against the rash. If the spots stay visible through the glass instead of fading, treat it as an emergency and call 112, especially with fever, drowsiness, a severe headache, a stiff neck or dislike of bright light. Also skip the online queue for a rash with high fever and feeling very unwell, rapidly spreading painful redness, widespread blistering or peeling, or any swelling of the lips, tongue or throat.
Can an online doctor diagnose a skin rash?
Often, yes. Most everyday rashes, including eczema, hives, fungal infections, contact reactions and shingles, have recognisable patterns, so clear photographs plus a video consultation can often provide enough information to identify the cause and start treatment. Some rashes still need in-person care: anything non-blanching, any rash with high fever, and rashes that resist diagnosis after photo review.[2]
A rash is a description, not a diagnosis, and dozens of conditions produce one. What a licensed doctor on Mobi Doctor actually does is pattern work: match the rash in your photos against how it behaves, where it sits and what else is going on, then either treat it or name the place you should be instead.
How an online consultation helps with a skin rash
- Built for visual diagnosis: rashes are one of the strongest use cases for photo-based medicine, because the diagnosis usually lives in the pattern: its shape, colour, edge, scale and distribution across the body.
- Triage you can trust: the first job is safety: the doctor checks for the handful of rashes that must not be managed online, including non-blanching rashes and rash with high fever, and says so plainly.
- Treatment for the cause, not "a rash": a steroid cream helps eczema, worsens fungal infections, and does nothing for hives. Naming the rash correctly is what makes the prescription work.
- A plan when it is not obvious: when a rash is genuinely ambiguous, you get the honest version: what it most likely is, what to watch, when to send new photos and when in-person examination settles it.
📷 Before your appointment: take one wider photo showing everywhere the rash appears, plus a sharp close-up of a typical patch in daylight. Include the edge of the rash: how it borders normal skin is often diagnostic. If it changes hour to hour, photograph it at its worst.
What the doctor checks in an online skin rash consultation
The assessment runs safety first, then pattern. The doctor will typically check:
- Blanching: whether the rash fades under pressure, using the glass test on camera with you if needed; non-blanching spots change everything.[2]
- Fever and how you feel: a rash in someone well and the same rash in someone feverish and drowsy are different emergencies entirely.
- Distribution: symmetrical or one-sided, inside creases or on outer surfaces, exposed skin or covered, one band of skin or scattered everywhere: each pattern shortens the list.
- The lesions themselves: flat or raised, scaly or smooth, blistered, weeping or dry, itchy or painful, and whether individual spots move around or stay fixed.
- The timeline: hours, days or weeks; what appeared first; and whether it began after a new medicine, an infection, travel, sun or a new product on the skin.
- Contacts and context: itchy household members (scabies until proven otherwise), unwell children at school, insect exposure, and recent illnesses.
- Your background: eczema, psoriasis, allergies, immune suppression and pregnancy, which all shift both the likely causes and the safe treatments.
What is a purpuric rash?
A purpuric rash is made of purple, red or brownish spots caused by blood leaking from small vessels into the skin, so the spots do not fade when pressed. Small spots are called petechiae and larger patches purpura or bruising. Because causes range from harmless to life-threatening, including meningococcal infection, blood-clotting problems and vasculitis, a new purpuric rash always needs medical assessment, and it is one rash online care does not treat.[2]
How do I do the glass test?
Press the side of a clear drinking glass firmly against the rash and watch the skin through it. An ordinary inflammatory rash fades or disappears under the pressure; a purpuric rash stays visible through the glass, because the colour is blood already outside the vessels rather than blood flowing through them. Check on a paler area of skin if the rash is hard to read, and check more than one spot. On darker skin, purpura can be subtler: look on paler areas such as palms, soles, the inside of the forearm, the conjunctivae or the roof of the mouth.[1]
What a non-blanching rash can mean
With fever, headache, stiff neck, drowsiness, cold hands and feet or dislike of light, non-blanching spots can mean meningococcal sepsis, an infection that moves in hours: call 112, and never wait for spots to spread, because in early meningococcal disease the rash may be sparse, late or absent.[1][4] Without fever, causes include vasculitis (in children, often IgA vasculitis, typically over the buttocks and legs), low platelet counts, medication effects and, in older adults, fragile-vessel bruising on the forearms. Fever or not, the route is the same: purpura is assessed in person, with blood tests where needed. This is a hard rule of ours, and a marker of any honest online service.
Rash with fever: when is it serious?
A rash plus fever usually means a viral illness that settles on its own, especially in children. It becomes urgent when specific features join it: a non-blanching rash, drowsiness or confusion, a stiff neck, dislike of bright light, breathing difficulty, cold or mottled hands and feet, severe pain, or a child who cannot be roused, will not drink or has a weak high-pitched cry. Any of those mean emergency care now, not a video call.[4][3]
Between "clearly fine" and "call 112" sits a wide middle ground: the feverish but alert child with a blanching rash, the adult with a viral-looking rash and a temperature. That middle ground is exactly where a video assessment helps (you can see a doctor over video, usually within 15 minutes): the doctor checks the danger features one by one, tells you what to actively watch for over the next hours, and books nothing you do not need. If the picture changes, non-blanching spots, worsening drowsiness, breathing trouble, you go straight to emergency care without waiting for anyone.
What is causing my rash? Common patterns
Most rashes the doctors see fall into a handful of patterns. Itchy raised wheals that move around within hours point to hives. A dry, itchy rash living in elbow and knee creases points to eczema. A slowly expanding ring with a scaly edge points to ringworm. A painful, blistering band on one side of the body points to shingles, where starting antiviral treatment early matters.[5] Hot, spreading, tender redness, usually on one lower leg, points to cellulitis, which needs antibiotics and sometimes urgent care. A rash fixed exactly where something touched the skin suggests contact dermatitis, covered on the skin allergies page, and intensely itchy burrows involving finger webs, wrists and other household members suggest scabies. Silvery scaly plaques on elbows, knees and scalp suggest psoriasis. The point of the consultation is that each of these has a different treatment, several have look-alikes, and two of them should not wait.
Which rash presentation belongs where?
This is the triage framework the doctors use, aligned with the cited guidance:[2][3]
Swipe sideways to compare →
| Presentation | Likely first step | Suitable for online care? | When referral or in-person care is needed |
|---|---|---|---|
| Non-blanching (purpuric) rash, fails the glass test | Emergency assessment; with fever or drowsiness this can be meningococcal sepsis | No | Always: call 112 with fever or feeling unwell; same-day in-person assessment even without |
| Rash with high fever, drowsiness, stiff neck or breathing difficulty | Emergency care | No | Always: call 112 |
| Itchy, blanching rash in someone otherwise well | Photo and video diagnosis, then targeted treatment: antihistamines, steroid creams or antifungals | Usually yes | If it resists diagnosis or fails treatment on schedule |
| Painful one-sided blistering band (suspected shingles) | Rapid assessment; antivirals work best started within 72 hours of the rash[5] | Usually yes | Rash near the eye, severe illness or weakened immunity: in-person, promptly |
| Hot, spreading, tender redness (suspected cellulitis) | Same-day assessment; antibiotics after review, with the edge marked and watched | Case-dependent | Fever, fast spread, red streaks, face involvement or feeling unwell: in person today |
Not sure which row is your rash? A doctor can tell you in one consultation.
See available times →Treatment options for skin rashes
What you can do yourself
While a rash is mild, blanching and you are otherwise well: moisturise dry, itchy rashes with a fragrance-free emollient, cool the skin rather than scratching it, and take a pharmacy non-drowsy antihistamine if the rash behaves like hives. Stop new products, keep washing gentle and lukewarm, and photograph the rash daily so its direction of travel is documented. Avoid two common self-inflicted wounds: do not put a steroid cream on an undiagnosed rash, because it masks and worsens fungal causes, and do not restart "a cream that worked before" for a rash that looks different this time.
Prescription treatment
A prescription is never issued without a consultation, because with rashes the diagnosis is the treatment decision. Once the cause is named, the doctor prescribes for it specifically: steroid creams of the right strength and duration for eczema and contact dermatitis, antifungals for ringworm and other fungal rashes, regular antihistamines for hives, antivirals for shingles caught early, and antibiotics only when there are genuine signs of bacterial infection such as cellulitis or infected eczema; antibiotics do nothing for the viral rashes that cause many fevers.[3] The doctor sets a review date, so a rash that is not clearing gets rethought rather than re-creamed.
When a rash is treated online, and when you need in-person care
Treated online: itchy, blanching rashes in otherwise well adults, including eczema flares, hives, fungal rashes, contact reactions and scabies; suspected shingles within the treatment window, when it sits safely away from the eye; mild presumed cellulitis in well adults, case by case, with the edge marked and strict review; and any rash you have simply been worrying about, where a firm name and plan is the treatment.
In-person care: every non-blanching rash, to emergency care with fever and to same-day in-person assessment without; rash with high fever and feeling very unwell; widespread blistering, peeling or mouth and eye involvement, including suspected severe drug reactions, the same day; suspected shingles involving the eye or forehead near it; babies under three months with any rash and fever; and rashes that remain undiagnosed after good photos and a video review, because at that point skin needs to be examined, and occasionally sampled, in person. When that is you, the doctor says so at the consultation and names the right place, rather than treating blind.
When to get in-person care
Do the glass test on any new rash. If the spots do not fade under a pressed glass, call 112 when there is also fever, drowsiness, severe headache, stiff neck, dislike of light, or cold mottled hands and feet; meningococcal infection can kill within hours and the rash can be a late sign.[1][4] Even without fever, a non-blanching rash needs same-day in-person assessment. Call 112 too for a rash with breathing difficulty or facial swelling, and get same-day care for widespread blistering or peeling, or a feverish child who is drowsy, floppy or not drinking.
How Mobi Doctor works
- Book a time that suits you: open daily 7am–11pm CET. You can see a doctor over video, usually within 15 minutes. No subscription, exact price up front.
- Upload your skin photos, then speak to a licensed doctor: a private video call: you describe what you feel, the doctor asks what matters, and you agree the right plan together.
- Leave with your plan: everything agreed before you hang up: your plan, and a prescription to use at a pharmacy near you where medication is clinically right for you. If your doctor decides you need to be seen in person, you get a full refund.
No sign-up needed
A skin rash can have more than one cause. Tick every symptom you have to see each condition page that mentions it. It finds the right page, not a diagnosis: a doctor gives you that on a video call.
Tap the body — an area or a point — to browse symptoms anywhere
Similar symptoms, different condition? Skin Allergy can start the same way. Compare them, or look up any other symptom in the full symptom checker.
Frequently asked questions about skin rashes
What causes a skin rash?
Most skin rashes in adults are caused by eczema, contact with an irritant or allergen, hives, a fungal infection, a viral illness, heat and sweat, insect bites, or a reaction to a new medicine. Less often a rash signals a bacterial infection such as cellulitis or impetigo, shingles, psoriasis, an autoimmune condition, or, rarely, bleeding under the skin from a serious infection or a blood problem.
What does a serious rash look like?
A serious rash is one that does not fade when a glass is pressed against it, especially with fever, headache, a stiff neck or drowsiness; a rash with high fever and feeling very unwell; a painful, hot, rapidly spreading red area; widespread blistering or peeling skin, or sores in the mouth or eyes; a rash with swelling of the lips, tongue or throat; or a rash starting days into a new medicine and spreading fast.
What is the glass test for a rash?
The glass test checks whether a rash fades under pressure: press the side of a clear glass firmly against the rash and watch through it. Most rashes blanch, fading as blood is pushed out of the skin. Spots that stay visible are non-blanching, meaning blood has leaked into the skin, which with fever can mean meningococcal infection. A non-blanching rash is a 112 call, not a video consultation.
My child has a rash and a fever. Should I book online or go in?
Mobi Doctor consultations are for adults aged 18 and over, so a child cannot be assessed online. Go straight to emergency care if the rash does not fade under a glass, or your child is drowsy, floppy, breathing fast, has a stiff neck or dislikes light, or is under three months with any fever. For a well, playful child with a mild rash and fever, a local doctor or pharmacist is the right route.
Can a doctor really diagnose a rash from a photo?
Very often, yes, because most rash diagnoses rest on pattern: shape, edge, scale, colour and where the rash sits on the body, all of which photograph well in daylight. The video call adds the story, the itch, the timeline, new products or medicines and your health background. Where a rash cannot be named from a photo, the doctor says so and arranges in-person examination or tests.
Can an online doctor prescribe treatment for a skin rash in Europe?
Yes, after a consultation. A prescription is never issued without one: the doctor identifies the rash from your photos and video first, then prescribes the treatment that matches the cause, whether that is a steroid cream, an antifungal, an antihistamine or an antiviral, with the prescription sent to a pharmacy near you. A rash that needs tests or emergency care is directed there instead.
Why is my rash not going away?
The usual reasons a rash persists: it is being treated as the wrong thing, a trigger such as a product, a detergent or a medicine is still present, treatment stopped too early, or a steroid cream is masking a fungal rash while it spreads. A rash that has lasted more than two weeks despite treatment needs a fresh look, photos in daylight, and sometimes a skin scraping or blood tests.
How long does a rash last?
It depends on the cause: hives fade within hours to days, heat rash within days of cooling, viral rashes in one to two weeks, contact dermatitis in one to three weeks once the trigger stops, a fungal rash in two to four weeks of antifungal, and shingles in two to four weeks. Eczema and psoriasis are long-term and controlled rather than cured. A rash outlasting its expected course needs review.
What can I do at home for an itchy rash?
At home, stop every new product on the area, wash with lukewarm water and a soap substitute, pat dry, apply a fragrance-free emollient, use a cool compress or a cooling menthol or calamine lotion for itch, wear loose cotton, keep rooms cool, cut nails short, and take a non-sedating antihistamine if the rash is hives. Photograph the rash daily in daylight, and do not put a steroid cream on an undiagnosed rash.
How can I prevent rashes?
Prevent recurrent rashes by moisturising daily if your skin is dry, using fragrance-free products, rinsing after swimming and sweating, wearing breathable fabrics in heat, drying skin folds, avoiding known triggers and allergens, treating athlete's foot before it spreads, protecting skin from sun, washing new clothes before wearing, and keeping a note of what preceded each rash so the pattern becomes clear.
Is it eczema, a fungal rash, hives or a viral rash?
Eczema is dry, itchy and poorly defined, in creases and on hands. A fungal rash is one or a few scaly rings with an active edge and clearer centre. Hives are smooth raised weals that move and fade within a day. A viral rash is widespread, flat or slightly raised pink spots on the trunk with a sore throat, cold or fever. Contact dermatitis maps exactly to what touched the skin.
Which rashes cannot be treated online?
Any non-blanching rash, any rash with high fever and feeling very unwell, widespread blistering or peeling, suspected severe drug reactions, rashes with breathing difficulty or facial swelling, shingles threatening the eye, and rashes in children. These need in-person or emergency care, and an online consultation is the wrong first step; the triage box on this page says where to go.
Is a rash different in pregnancy or in older people?
In pregnancy, itchy rashes are common and mostly harmless, but a rash starting in the stretch marks late in pregnancy, or intense itch of palms and soles without a rash, needs the maternity team. In older people, rashes more often come from medicines, dry skin, shingles or scabies in care settings, and a persistent scaly patch that will not heal should be examined for skin cancer.
- Meningitis (bacterial) and meningococcal disease: recognition, diagnosis and management (NG240), NICE, National Institute for Health and Care Excellence, 2024.
- Purpura, DermNet New Zealand Trust, reviewed 2023.
- Fever in under 5s: assessment and initial management (NG143), NICE, National Institute for Health and Care Excellence, 2019 (updated 2021).
- Meningitis: fact sheet, World Health Organization, 2025.
- Herpes zoster (shingles), DermNet New Zealand Trust, 2024.
- Meningitis: symptoms, NHS, National Health Service (UK), reviewed June 2026.
This page is for information only and is not a substitute for a medical consultation. Guideline links are provided for transparency; treatment decisions are made with your doctor.
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