Common questions
Contact Dermatitis:How do I figure out what caused it?
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.
Contact Dermatitis:How long does it take to clear up?
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.
Contact Dermatitis:Is it contagious?
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.
Contact Dermatitis:Will the allergy ever go away?
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.
Contact Dermatitis:Why did this appear on my eyelids when I never put anything there?
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.
Contact Dermatitis:Can I just use hydrocortisone from the pharmacy?
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.
Ringworm:Is there actually a worm?
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.
Ringworm:How long am I contagious?
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.
Ringworm:Did my cat give it to me?
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.
Ringworm:Can I use athlete's foot cream on my body?
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.
Ringworm:Why does it keep coming back?
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.
Ringworm:Do I need tablets?
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.