Localized Rashes

A localized rash is found only on one part of the body, like the left arm, the diaper area, or the mouth, and it is NOT typically symmetric (i.e. it is found on only one hand, not both, or just one cheek and not the other, etc). Sometimes it is symmetric, like heat rash on the face and neck. Localized rashes are usually due to the body’s external response to something. (If you think you have a widespread rash, follow this link instead: Widespread rashes) Here are a few of the common localized rashes in kids, and what to do:

  • Diaper rash: most diaper rashes are irritation from urine, stool, moisture, and the rubbing of the diaper. Sometimes there are yeast or bacterial infections. If most of the redness is on the exposed/visible surfaces, it’s probably irritation. If most of the redness is hidden within the creases, it’s probably yeast. Either way, start by washing the area with a gentle skin cleanser using your fingers, and then dry well. If it looks most like irritation, apply a zinc oxide cream. If it looks most like yeast, consider an over-the-counter antifungal (i.e. “jock itch cream”). Try to check and change your diaper very frequently until the problem resolves, maybe even doing some diaper-free time. And if it’s not responding to these measures or has a lot of weeping, zit-like bumps, cracks and fissures, come see me!
  • Heat rash/prickly heat: it doesn’t necessarily have to be hot out, your child could be sweating from activity or bundling. You’ll see tiny reddish bumps often around the head, neck, chest and shoulder areas. They tend to be itchy/uncomfortable. Try to reduce sweating by wearing breathable, temperature-appropriate clothing. A cool washcloth or cool bath may help.
  • Rash around the mouth (red/pink): this is a very common rash in kids, usually brought about by contact irritation from things, like food, saliva, licking, etc. This is NOT generally an allergic reaction, unless there are also hives (usually full-body), SWELLING of the lips/tongue/eyes, shortness of breath, ill appearance, etc. Common foods that irritate are acidic or messy foods and fruits, like citrus, tomato, berries, etc., but it could be any food. You’ll see this a lot in kids who get food on their face when eating, kids who lick their lips a lot, kids who suck on or chew on things a lot, or rub their face/mouth frequently - you get the picture. Best thing to do is keep it clean and protected. You don’t necessarily have to avoid those foods, just be aware and take care of the skin during those exposures. Wash carefully with gentle skin cleanser, coat with protectant prior to eating (such as vaseline, aquaphor, or food-grade coconut oil), rinse area after eating. Other considerations: cold sores, impetigo (see next two items).
  • Cold sores: these are a group of fluid-filled blisters on a bright red base on and around the lips, usually painful, then scabbing. Most cases of rash around the mouth are NOT cold sores - only think about these if you have a major CLUSTER of painful fluid-filled blisters that is not symmetric (i.e. it’s just on the right or left side of the mouth). They will typically resolve on their own, but if you want me to confirm whether or not the virus is present for future reference, you’ll need to come in to my office in the first day or two while the blisters are still fresh so I can do a lab test (lab diagnosis is not necessary, however, just optional). In severe cases, like in small infants, treatment may be warranted either for a single severe illness or for recurrent illness. Otherwise, wash hands well to prevent spread, prevent contact with the eyes, and take ibuprofen for pain if present. Some forms of hand-foot-and-mouth can be confused with this disease, but this is also a virus that generally resolves on its own and doesn’t require treatment in an otherwise well-appearing child. If you have any further questions, please set up an appointment so I can take a look and discuss this with you.
  • Lesions with a “honey-colored” crust: this may be impetigo, a superficial skin infection. It is often seen around the mouth and nose, but can be anywhere. This will need treatment but can wait to see me until the daytime unless your child is unwell or has other symptoms of concern, such as signs of a deep skin infection (see next item).
  • Red, swollen, firm, hot and painful rash: this may be a deep skin infection (cellulitis). This will require medical attention. If it seems large (i.e. tennis ball size or larger), rapidly progressive, your child is ill appearing, or it is in a vital place (i.e. on the face), this would need attention right away. If it is smaller, not spreading quickly, your child is well appearing and does not have fever, it can wait to see me until the daytime. Just don’t wait too long to be seen with this one.
  • Insect sting/bite reaction: Redness and swelling is a common reaction to the venom of insect stings and bites, and is NOT an allergic reaction unless there are full-body symptoms (hives, oral swelling, breathing trouble, etc). The swelling at the site of the bite/sting can be very impressive at times, but is usually not bothersome apart from how frightening it may look. The swelling should not be painful, it should be soft and “poofy,” not hard and leathery, and there should be no fever. Also make sure that circulation beyond the swelling is normal - pinch a fingernail and the blood should rush back to it within 3-4 seconds maximum. If everything otherwise looks good, and the swelling ceases and begins to resolve after a few days, there is not necessarily a need to bring your child in. But if it looks like it may be pretty bad or going out of control, I’d like to see them.
  • Blistery local rash in an area that had contact with something: this is a reaction to some kind of irritant (contact dermatitis). Examples include poison ivy or poison oak, or any host of different plants or chemical products. Make sure to isolate the child from the offending irritant and wash their hands. Try to prevent hand-to-eye contact. If they came in contact with a known chemical, call poison control (1-800-222-1222). Gently wash the affected area with a very mild, non-irritating cleanser, being careful not to pop the blisters. Apply a cool compress and keep your child from scratching it. Medications are not very useful for this condition. Topical hydrocortisone (over the counter) can help a little bit, particularly if applied very early on. Antihistamines are often used for the itching, but aren’t very effective for this condition. Do not apply other ointments (like antibiotic ointments) as most things will make this condition worse. In severe cases, there are some medications I can prescribe, so make an appointment if it looks very severe.
  • Dry, pink, circular patch: this is usually either ringworm (a yeast infection) or eczema. If the patch is in the form of a ring (with central clearing), you can try home treatment with an over-the-counter antifungal for a few weeks until it is completely gone. If the patch is more of a solid circle (no central clearing), and especially if there is a family history of eczema or dry skin, it may be eczema, and it’s best to see me for this so I can make the diagnosis and talk about how to prevent and treat it.
  • Bruising. Bruising on areas that get hit a lot, like the shins, is extremely common in children and is completely normal. But if they have lots of bruising in unusual places that don’t usually get bonked, they should be evaluated, sometimes urgently. If your child is completely well it can wait until the next day to see me. If they are unwell, or if the bruising is sudden and widespread, they should be evaluated emergently.



If your rash doesn’t fit any of these common descriptions, please make an appointment with me so I can take a look and figure out what it might be. And again, while most rashes are not urgent, as always, if your child has other symptoms that are concerning for something more urgent, please page me.

Because some rashes can change surprisingly quickly, take a good quality photo and bring it with you to your appointment. I cannot diagnose rashes over email because I really need to see them in person to tell what’s really going on, but sometimes a photo can help augment your visit when I see your child.

Same-day appointments

For urgent needs, same-day appointments are available Monday through Friday. Please call as early in the day as possible, the more notice we have the easier it is to fit everyone in. 

Need help outside of office hours?

Firstly, if your child has an emergency, please call 911 or go directly to the ER - they will contact us if needed once your child has been evaluated.

Urgent Care centers can also be helpful when something needs to be seen outside of office hours but it's not an emergency. 

For our list of preferred Urgent Cares and ERs, see our resources page.

And if you have something that might need urgent attention but you're not sure/don't know what to do, we can help: