Skip to cookie consent Skip to main content

Urgent Care for Rashes

Contributors Joseph W. Kopp, MD and Katherine D. Rose, MD
11 minute read
Man with itchy rash

Rashes—areas of bumpy, irritated, or swollen skin—are incredibly common and can be extremely uncomfortable. You’ve probably had one at some point in your life, whether you’ve stepped in poison ivy or had a reaction to a new body wash.

“Rashes are such a broad category, and can range from something that resolves after a couple of hours to having a cause that can be extremely dangerous, and everything in between,” says Mass General Brigham emergency medicine doctor Joseph W. Kopp, MD. In this article, learn more about the different types of rashes and when you should seek medical attention.  

When should you seek medical care for a rash?

If you or a family member has a new rash, call your primary care provider (PCP). Your doctor's office can recommend next steps and assist with any urgent issues.

“It’s always a good idea to contact your PCP first. They know you the best, they know your medical and family history, and they can tease out some of those subtle details,” explains Dr. Kopp. 

It’s especially important to call your PCP if you have any of these signs or symptoms, which may indicate a more serious medical problem: 

  • A fever
  • Feeling dizzy or lightheaded
  • A racing heart rate
  • A rash that has spread to your mucus membranes (the lining of the nose or mouth)
  • A rash along your groin, your joints, or the palms of your hands
  • A rash with blistering or bleeding

If you’re having trouble breathing, or you’ve had a previous episode of a serious allergic reaction known as anaphylaxis, call 911 or go to the emergency room.

If you have a rash that’s not a medical emergency, many Mass General Brigham primary care practices for adults and children offer same-day, in-person, and virtual visits. If you don’t have a PCP or no appointments are available, you can go to urgent care.

How are rashes diagnosed?

During an in-person visit for a rash, health care providers examine your skin carefully, touching the surface of the rash. They take vital signs, like your temperature, and may order blood work. Your provider will ask questions about your lifestyle, diet, and things you may have come in contact with that may be causing the rash.

Dr. Kopp recommends that patients take photos to keep a visual record of their rash. “If you’re being seen after you’ve had the rash for a couple of days, it can be really helpful to have pictures to show how the rash might have changed,” he says. Seeing how your rash has evolved over time will help your health care provider diagnose and treat it. When it comes to diagnosing and treating rashes, it’s important that patients can identify anything new or unusual when it comes to their skin.

Rashes in patients with darker skin tones

“For people with darker skin, it can be much more difficult to see rashes in detail,” Dr. Kopp advises. “That’s when the patient’s input will be very important.”

“We teach our residents and our med students to pay more attention and ask the detailed questions so that we’re not missing any of those dangerous rashes in our patients with darker skin tones,” says Dr. Kopp. This approach to medical education is a one way that Mass General Brigham is committed to making clinical care more equitable.

Can I see a virtual doctor for a rash?

For most rashes, seeing a health care provider in person is best so they can examine and touch the rash. “There are important medical differences between a rash that’s flat, that you can’t feel, versus a rash that has bumps on the surface or is textured, which can lead you in a different direction in terms of the cause,” says Dr. Kopp.

For mild rashes, Mass General Brigham Virtual Urgent Care is also an option for care. It’s open to all patients ages 3 and up, even if they haven’t seen a Mass General Brigham provider before. Both new and current patients can schedule a virtual urgent care visit for that day or the next day on Mass General Brigham Patient Gateway. 

“It will be a more limited exam of the skin using a camera. We won’t be able to examine any sensitive areas, like the groin. But we can do an initial evaluation and recommend if patients need to get any additional testing or should be seen in person,” Dr. Kopp says.

Common causes of skin rashes

Rashes have a wide range of causes, including:

  • Infection
  • Allergens or irritants
  • Bug bites
  • Autoimmune diseases
The infectious disease rashes that we worry about, like Lyme disease, cellulitis, and shingles, need medical attention.

Joseph W. Kopp, MD

Emergency Medicine Doctor

Mass General Brigham


Rashes can stem from viruses, bacteria, fungi, or parasites that cause infections like:

  • Shingles
  • Cellulitis
  • Chickenpox
  • Lyme disease
  • Ringworm
  • Hand, foot, and mouth disease
  • Fifth disease
  • Athlete’s foot
Lyme disease rash

Viruses like the common cold also can cause a mild rash. “It’s very common, especially in childhood, and usually resolves on its own,” says Dr. Kopp. “The infectious disease rashes that we worry about, like Lyme disease, cellulitis, and shingles, need medical attention.”

To prevent catching or spreading infectious skin diseases, practice good hygiene: 

  • Wash your hands regularly with soap and water.
  • Avoid contact with people who have infections.
  • Launder your bed linens and towels regularly.
  • Wear shower shoes or sandals in shared spaces like pools or locker rooms.
  • Keep feet clean and dry.

Allergens and irritants

Depending on the allergen and where you came into contact with it, you may develop a rash like hives or contact dermatitis. “If you’ve eaten an allergen, the rash tends to spread across the whole body like hives. If your skin was exposed to an irritant like poison ivy, we’ll look at the pattern to see what may have caused the rash,” Dr. Kopp says.

If you’ve developed a rash after using a new lotion, soap, or shampoo, you may have an allergy or an irritation to a chemical in the product. Other substances may not cause an initial reaction, but can cause irritation with longer exposure. “If you have sensitive skin, and you get into a pool that has strong chlorine or cleaning chemicals, it can irritate your skin. It’s important to pay attention to what your body’s telling you,” says Dr. Kopp. 

An allergy to medication also can cause rashes. This usually happens soon after taking a new medicine for the first time, though “a new rash or a new allergy to a medication you’re taking can pop up at any point in time,” Dr. Kopp clarifies.

If you suspect you have a rash caused by allergies, you may need to see an allergy specialist. Until you have a confirmation of what you’re allergic to, try to avoid consuming or having other contact with the potential allergen. “If you have an allergic reaction, every time you’re exposed the reaction can become more severe. This time, it might be a rash; next time it might be a rash and difficulty breathing. We certainly don’t want it to progress to that level,” Dr. Kopp says. “You’re going to want to see an allergist and get formal testing in a controlled environment.”  

Insect bites

You may develop a rash following an insect bite or sting if your immune system reacts to substances or venom in the insect’s saliva or stinger. At the site of the bite, you may experience: 

  • Itching
  • Swelling
  • Soreness
  • Redness
  • Pain

If you have a severe allergy to an insect’s venom, you can develop anaphylactic shock, where your throat tightens and makes it difficult to breathe. If you experience those symptoms, call 911 immediately.

Some insects can spread bacterial or viral diseases that cause rashes, including:

  • Lyme disease
  • Babesiosis
  • Chagas disease

These diseases can cause additional debilitating symptoms, so it’s important to seek medical care if you suspect you’ve been exposed.

If you scratch a bug bite, you may create an opening in the skin for bacteria to enter. This can lead to an infection like cellulitis. Try to avoid scratching a bug bite if possible. 

Eczema rash

Autoimmune diseases

An autoimmune disease occurs when your body’s immune system attacks your own healthy cells by accident. Some of these autoimmune disorders can trigger skin inflammation and rashes:

Autoimmune diseases are often chronic conditions that need to be carefully managed by your PCP. 

Treatment for rashes

Most mild rashes will clear up on their own, but consult with your health care provider about the best way to relieve your symptoms. They may recommend you:

  • Use mild, unscented, or hypoallergenic soaps, lotions, and skin products.
  • Avoid any products or allergens that have given you a reaction in the past.
  • Try not to scratch the skin.
  • Apply topical medications, like calamine lotion or Benadryl® ointment.
  • Take antihistamines or prescribed medications for allergies.
  • Be cautious in using hydrocortisone or other steroid ointments. These suppress the immune system and can make fungal rashes worse.

If you have a more serious rash that requires urgent medical attention, follow your health care provider’s instructions for treatment. 

Joseph W. Kopp, MD


Emergency Medicine Doctor


Internal Medicine Doctor