Impetigo is a common bacterial skin infection that sits in the top layer of the skin. It shows up as sores that break open and dry into a golden-yellow crust. It is very contagious, mostly affects children, and clears quickly once it is treated. Contact dermatitis is a rash caused by something that touched the skin. It comes in two forms - irritation from a substance that would bother anyone given enough exposure, and an allergic reaction to something only some people react to. Both clear once the cause is found and removed.
The same eight facts on every condition comparison.
It is a bacterial skin infection.
Staphylococcus aureus and group A streptococci are the usual causes.
It has two forms.
Nonbullous impetigo forms crusts; bullous impetigo forms blisters.
Bacteria enter broken skin.
Eczema, scratches and bites are common entry points.
Testing is selective.
Swabs help with recurrent, resistant or unusual cases.
It is eczema from contact.
A substance touching the skin provokes the rash.
There are two types.
Irritant dermatitis damages the barrier directly; allergic dermatitis is a delayed immune reaction.
Patch testing finds allergies.
It differs from skin-prick testing.
The exposure is part of treatment.
Identifying what touched the skin guides care.
Non-bullous impetigo Sores with honey-colored crusts; most common.
Bullous impetigo Larger fluid-filled blisters.
Ecthyma Deeper, punched-out ulcers.
Irritant contact dermatitis Damage from soaps, solvents or water; most common.
Allergic contact dermatitis Immune reaction to nickel, fragrance, plants and more.
Bacteria infect the superficial skin, often after a small break in the barrier. Shallow sores or blisters can release fluid that dries into a honey-colored crust.
Skin contact can cause inflammation through direct irritation or a delayed allergic reaction. These are different routes to a rash that may itch, swell, blister or scale.
Impetigo. Most common in young children, although any age can be affected.
Contact Dermatitis. Can begin at any age after irritation or sensitization to a contacting substance.
Impetigo is a skin infection caused by staph or strep bacteria entering through small breaks in the skin.
Contact dermatitis happens when something touching the skin either damages it directly or sets off an allergic reaction. The rash shows up where the contact happened.
People with eczema or a family history of allergies react more easily.
Evidence labels come from each condition’s own treatment list.
General antiseptic ointments from the shelf are not the same thing as a prescription antibiotic ointment and usually do not clear impetigo. The main cost of trying them is time: the infection keeps spreading and the child stays off school for longer than they needed to.
The mildest topical steroid, and enough for a small patch on the body once the contact has stopped. Use it twice a day for one to two weeks rather than dabbing it on now and then. It is often too weak for the hands or feet, and on the face or eyelids it should be short-term and worth asking about first.
Contact dermatitis is not driven by histamine, so antihistamines do very little for the rash itself. A sedating one at night can help you sleep through the itching instead of scratching, which is worth something. The non-drowsy daytime ones sold for hay fever will not make much difference here.
Worth naming because they are so often reached for. Neomycin and bacitracin are among the most common contact allergens there are, so an ointment used on an itchy rash can become the reason the rash will not go. Unless the skin is genuinely infected, plain petroleum jelly does the same job with none of the risk.
Plain petroleum jelly, or any thick fragrance-free ointment, rebuilds the barrier that irritation broke. Barrier repair is genuinely half the treatment in irritant hand dermatitis, and it works because it has no fragrance, preservative or botanical in it to start a second reaction. Apply after every hand wash, not once a day.
An oatmeal bath can take the edge off the itch of a widespread reaction, in cool rather than hot water. It is comfort only. Pick a plain one, because an itch product with fragrance or botanicals in it is a common way people acquire a second allergy on top of the first.
The usual first choice for a small number of patches, applied three times a day for about five days after the crust has been softened off. For a few sores it works as well as tablets and avoids their side effects. It is also the ointment used inside the nostrils when impetigo keeps coming back and long-term carriage in the nose is the reason.
An equally effective alternative ointment for a few small patches, used three times a day for five to seven days. Which of the two you are given depends mostly on local resistance patterns and what your country prescribes first. Neither is enough on its own once the infection is widespread.
Ozenoxacin cream. A newer antibiotic cream for the crusted form, used twice a day for five days. It is an option where resistance to the older ointments is a problem, and it works against some resistant staph. It is not widely stocked and is usually the more expensive choice.
A mid-strength steroid cream or ointment, the usual prescription for contact dermatitis on the body, arms or legs. Two weeks of it will clear most reactions once the contact has stopped. It is too strong for the eyelids and the folds, and it is a treatment for the inflammation, not for the cause.
Clobetasol Propionate. A potent steroid ointment for hands and feet, where the skin is thick enough that milder creams barely register. It is used in short bursts of two to three weeks with breaks in between, not continuously. Nothing above the neck, and remember that hand dermatitis takes six weeks or more to settle even when the steroid is doing its job.
A non-steroid ointment for the eyelids, face and skin folds, where repeated steroid use thins the skin. It calms the same immune reaction without that risk, which makes it useful for eyelid dermatitis that keeps returning while the trigger is being tracked down. It stings for the first few days, and that usually passes.
A mild steroid stronger than over-the-counter hydrocortisone but gentle enough for the face and eyelids in short courses. It is the usual first prescription when a reaction has landed above the neck. Use it for the days it is prescribed for, not as something kept in the drawer.
A gentler alternative to tacrolimus for the face and eyelids, and easier to tolerate for people who cannot get past the initial burning. It is not strong enough for hand dermatitis. Like tacrolimus, it buys comfort while the actual trigger is being identified.
The usual tablets or liquid when the infection is widespread, spreading fast, blistering, or the person feels unwell. A course runs about seven days, and the contagious period ends after roughly the first day of it. Finish the course even once the crusts have gone, because stopping early is one of the common reasons it comes straight back.
Used when there is a penicillin allergy, or when a swab shows resistant staph. It works well against the bacteria that cause impetigo. It upsets the stomach more than the first-choice options and, uncommonly, can cause a serious bowel infection, so any diarrhoea during or shortly after a course is worth reporting.
Reserved for adults and older children when a swab shows resistant staph, and not used in young children or in pregnancy — ask your doctor if either applies. It is a reasonable option for the age group that fits it, but for the usual patient with impetigo, a small child, it is not the drug.
Steroid tablets for a widespread, blistering reaction, most often poison ivy covering large areas or a rash on the face that is closing an eye. The course has to run two to three weeks with a taper; the short packs are the usual reason the rash rebounds a few days after finishing. It is for the big reactions only, not for a patch on one arm.
A short specialist course for severe hand dermatitis that has not responded to strong steroids and proper avoidance. It works quickly and reliably, which is exactly why it is used for a few months rather than long term — blood pressure and kidney function have to be watched throughout. It is a bridge, not an answer.
A weekly tablet sometimes used for chronic hand dermatitis when avoidance and creams have genuinely failed. The evidence in contact dermatitis specifically is thin, mostly borrowed from eczema. It needs regular blood tests, and it is a specialist decision rather than a next step.
Used only when bacteria have moved into the broken skin — spreading warmth and pain, pus, or fever. They treat the infection sitting on top and do nothing to the dermatitis underneath, so the steroid and the avoidance carry on alongside them.
An injected biologic increasingly asked about for chronic hand dermatitis. Reports are encouraging for the eczema-like cases, but it is not approved for allergic contact dermatitis and some allergens appear not to respond to it. It does not replace finding and removing the trigger, and it is a specialist conversation.
Impetigo moves fast - it appears over days and, treated, clears in about a week. Untreated it usually resolves in around 2 to 3 weeks, but it spreads much further meanwhile, stays contagious throughout, and carries more risk of complications. Ecthyma, the deeper form, takes several weeks and does scar.
Timing is the best clue to which form you have. The rash is temporary; the allergy is not - sensitization is generally lifelong, so avoidance is permanent. Once the substance is named and avoided, most people stay clear.
Cellulitis
Occasionally the bacteria get past the top layer and into the deeper tissue. The area around the sores becomes swollen, hot and increasingly painful, with redness or darkening spreading outward into normal skin, and the person often feels unwell with it. It is uncommon and it is treatable, but it needs antibiotic tablets rather than a cream, and it is a same-day problem rather than one to watch overnight.
Ecthyma — the deeper form
When the infection punches through into the layer below, it forms a punched-out ulcer under a thick, hard crust, most often on the lower legs. It is the one form of impetigo that heals slowly and does leave a scar. It is more likely where sores have been picked at, where treatment was delayed, and in people with diabetes or a weakened immune system. It needs antibiotic tablets, not an ointment.
Days off school and spread at home
Most settings ask for about 24 hours of antibiotic treatment before a child returns, with any remaining sores covered, so treating early is what gets them back soonest. The bigger cost is usually at home: without separate towels, bedding and hot washing, it works its way through the other children and sometimes the adults, and each new person starts the clock again.
Infection in the broken skin
Weeping, cracked or scratched skin gives bacteria an opening, most often on the hands. The signs are honey-colored crusts, pus, increasing pain, or redness and warmth spreading outward. It is common and it is treatable, but it needs antibiotics rather than more steroid cream, so it is worth being seen rather than waiting it out.
Chronic hand dermatitis
When the exposure carries on, hand dermatitis stops settling between flares. The skin thickens, the normal lines deepen, and painful cracks open across the fingertips and knuckles that catch on everything and are slow to close. It is the reason contact dermatitis is a leading work-related skin problem, and it is largely preventable by naming the cause early instead of treating the rash for months.
Time off work
Hand dermatitis is one of the leading work-related health problems, and for people in wet or chemical work it can mean weeks of light duties, a change of role, or leaving a trade. It is also the part most often left out of the conversation. Naming the cause early, and getting the right gloves and routine in place, is what keeps the job.
Seek treatment for suspected impetigo. Spreading redness, fever, marked pain or a newborn with blisters needs prompt assessment.
Seek help for persistent or recurrent rash; patch testing may identify contact allergy. Pain, spreading warmth, pus or fever require prompt assessment.
Until about 24 hours after antibiotics start, or until the sores have fully dried and crusted if untreated, which takes far longer. That is why treatment is offered even though it would clear on its own - it cuts the contagious period from a week or more to about a day.
Most settings ask for around 24 hours of antibiotic treatment first, with remaining sores covered. Rules vary between countries, schools and nurseries, so check the policy.
Ordinary impetigo almost never scars, because it sits in the top layer of skin. Flat pink, brown or pale marks fade over weeks to months, more slowly on deeper skin tones. Ecthyma, the deeper ulcerating form, does scar, and picking raises the risk in any form.
Usually eczema that is not fully controlled, which keeps supplying broken skin. Other reasons are scratching from bites or scabies, shared towels and bedding, or long-term Staphylococcus aureus in the nose. Look at those rather than repeat the antibiotic.
Yes, though it is much less common in adults with healthy skin. The risk rises with eczema, a cut, a graze or any other break. Separate towels, handwashing after applying the ointment, and hot washing of bedding reduce the chance.
It depends how much skin is involved. A prescription ointment works as well as tablets for a few patches and avoids the side effects of oral antibiotics. Tablets or liquid are for widespread infection, rapid spread, large blisters, or an unwell child. Make that call with a doctor.
Start with location and shape, not a list of products. Photograph the rash, note where its edges are, and look for an object or habit that matches that outline. An allergic reaction shows up one to three days after contact, so look at what happened two days before, not that morning. Include things you have used for years - those are the likeliest candidates, not the least. If a few weeks of attention does not settle it, patch testing ends the guessing.
An irritant reaction improves within days of contact stopping. An allergic reaction takes two to four weeks to settle even with treatment, because the immune cells doing the damage take that long to stand down. Hands are slowest, often six weeks or more, because the skin there is used and washed constantly. Judging it at day three tells you very little.
No. This is your own skin reacting to a substance, not an infection. You cannot pass it on by touch. If two people in a household get the same rash, they were both exposed to the same thing.
Generally no. Once your immune system has learned a substance, that memory is permanent, and tiny amounts can trigger a reaction years later. In practice it is less grim than it sounds - people who know their allergen and avoid it stay clear indefinitely, and the avoidance is usually narrower than they feared.
Eyelid skin is the thinnest on your body, so it reacts to amounts the rest of your skin ignores. Nail polish, hair products, face creams and airborne particles reach the eyelids from your hands or from your scalp. When a rash is on the eyelids alone, the cause is usually somewhere else.
For a small, mild patch on the body, often yes, alongside stopping the contact. Over-the-counter hydrocortisone is a mild strength and rarely clears thicker skin on hands or feet. On the face and eyelids keep it short-term, and ask first. It treats the inflammation, not the cause - if the rash returns each time you stop, find the trigger.
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