The common psoriasis pattern with persistent well-defined thick scaly plaques. Ringworm is a common fungal skin infection that spreads outward in a scaly ring with a raised edge. There is no worm involved. It clears with antifungal treatment, as long as the treatment is used for long enough and steroid creams are kept away from it.
The same eight facts on every condition comparison.
Plaque Psoriasis Two distinct pink plaques have a dry, scaly surface.
Tinea corporis (body ringworm) Rings on the body and limbs.
Tinea capitis (scalp ringworm) Generated illustration. Scaly patches with hair loss.
Tinea cruris (jock itch) Jock itch in the inner thighs.
Tinea pedis (athlete’s foot) Athlete's foot.
Immune signals speed up the production of skin cells. The cells accumulate in thickened, inflamed plaques with surface scale.
Dermatophyte fungi grow in the keratin of the outer skin and spread outward. Inflammation and scale often concentrate at an expanding border, while the center may look clearer.
Plaque Psoriasis. Can start at any age, with different patterns at different life stages.
Ringworm. Can occur at any age after exposure to an infected person, animal or contaminated material.
Immune inflammation speeds skin-cell turnover; psoriasis is not contagious.
Ringworm is a fungal infection of the skin's outer layer. It isn't caused by a worm; the name comes from the ring-shaped rash.
Evidence labels come from each condition’s own treatment list.
The most effective cream you can buy for ringworm on the body, and it kills the fungus rather than just stopping it growing, so the course is shorter — often one to two weeks. Take it a couple of centimetres past the visible edge. It does not work on the scalp or the nails, where the fungus sits out of reach.
The familiar azole creams, sold everywhere and cheap. They work well on body ringworm, but they stop the fungus growing rather than killing it, so they are used twice a day for two to four weeks and for one to two weeks after the skin looks clear. Stopping at the point it looks better is the usual reason it returns.
An older antifungal, most often sold as a powder or spray. It works on body and foot ringworm but more slowly than terbinafine, and it is weaker on stubborn patches. Its real use is keeping the feet and shoes dry after treatment, since untreated feet are what reseed the rest of the skin.
It does have some antifungal activity, and it is the home remedy people ask about most. The trouble is that it clears ringworm far less reliably than a pharmacy cream, it commonly irritates the skin, and weeks spent on it are weeks the patch keeps spreading. There is no reason to choose it over a proven cream that costs about the same.
Common options for localised plaques; selection depends on site and thickness.
Ketoconazole 2% cream. The prescription strength of a familiar antifungal, used for body ringworm that has not cleared on an over-the-counter cream, and for larger patches. It is applied once or twice a day for two to four weeks. Like every cream, it is the wrong tool for the scalp and nails.
Ciclopirox cream. A broad antifungal that also settles inflammation a little, which suits an angry, very itchy patch. It is a reasonable choice when azole creams have not worked or have irritated the skin. It still needs the full course and the same treating past the edge.
Econazole cream. A prescription azole cream used much like clotrimazole, applied once daily for two to four weeks. It has some activity against bacteria as well, which is occasionally useful in a moist fold or between the toes where both are present.
Terbinafine tablets. The usual tablet for ringworm that cream cannot reach — scalp infections, nails, widespread patches and stubborn cases. Typically two to four weeks for the scalp and several months for nails, because the nail has to grow out. Liver blood tests are checked for longer courses, and it interacts with a number of other medicines.
An equally effective alternative, often used for nails, for widespread infection and for cases that have not responded to terbinafine. It is sometimes given in pulses of one week a month. It interacts with a long list of common medicines, including statins and some heart drugs, so bring your full list to the appointment.
The oldest scalp treatment and still a first choice in children for some species of fungus. It needs six to twelve weeks, and it is absorbed much better when taken with a fatty meal. Newer tablets work faster, so which one is used depends on the species the lab identifies.
A once-weekly tablet, used mainly when terbinafine and itraconazole do not suit. It clears dermatophyte infections less reliably than either, so it is a second-line option here rather than a first choice, even though it is the antifungal most people have heard of.
Plaque psoriasis often alternates between flares and quieter periods. Treatment can achieve good control, but maintenance is commonly needed and the tendency to psoriasis remains.
Untreated, ringworm expands slowly rather than resolving. Treated, it is predictable. Scalp and nail infections run much longer and need tablets — weeks for the scalp, months for nails, which have to grow out.
Psoriasis can accompany inflammatory joint disease. Report persistent joint stiffness or swelling.
Kerion and permanent hair loss
Scalp ringworm can turn into a kerion — a boggy, tender, pus-oozing swelling where the immune reaction has gone deep around the hair follicles. It happens mostly in children, and it can destroy follicles and leave a permanently bald scar. Oral antifungal tablets started early are what prevent it, which is why scalp involvement is never treated with cream.
Ringworm hidden by steroid cream
Steroid cream calms the itch and flattens the edge while the fungus keeps spreading underneath. What comes back is larger, shapeless and much harder to recognize, and it is often treated as eczema for months. If a rash improved on a steroid and then grew, say so at the appointment — it changes both the diagnosis and the test.
Nail Fungus
Ringworm that reaches the nails thickens and discolors them and lifts the nail from its bed. It matters twice over: creams cannot reach fungus under a nail, so it needs months of tablets, and until it is treated it acts as a reservoir that reseeds the feet, groin and body again and again. This is one of the most common reasons ringworm keeps coming back.
Seek care for painful cracks, widespread flares, joint symptoms or uncertain diagnosis.
Seek care for widespread, recurrent or uncertain rash, or scalp involvement. Steroid cream alone can disguise and worsen a fungal infection.
The common psoriasis pattern with persistent well-defined thick scaly plaques.
Use bland moisturizer, avoid rubbing and follow a site-appropriate treatment plan.
Seek care for painful cracks, widespread flares, joint symptoms or uncertain diagnosis.
No. Ringworm is a fungal infection of the outer layer of skin, related to athlete's foot. The name describes the rash, named long before the cause was understood.
For most body infections, much less so after a day or two of treatment. Contact sports set their own rules — wrestling commonly requires around 72 hours of treatment and the area covered. Check with your club or school rather than guessing.
Possibly. Kittens and puppies are common sources, often with only a small patch of thin or crusty fur, or nothing. If a new pet arrived shortly before the rash, ask a vet to check it. Treating people and not the animal is a common reason it keeps returning.
Yes. Same medicines — terbinafine, clotrimazole, miconazole — and the same infection elsewhere. The exception is the scalp and nails, where creams do not work whatever the tube says.
Usually one of three reasons: treatment stopped as soon as the skin looked clear, an untreated reservoir such as athlete's foot or fungal toenails, or a steroid cream somewhere in the routine. Occasionally an infection really is resistant, which needs testing and a prescription.
Not for a small patch on the body, which almost always responds to cream. Tablets are needed for scalp and nail infections, and widespread, deep or stubborn cases. That needs a doctor, partly because some oral antifungals interact with other medicines.
Sources
