When to Worry About a Rash in Adults: 9 Signs

Key takeaways:

• A rash is not usually a sign of a serious medical condition.
• Persistent rashes or ones that are accompanied by other symptoms warrant a call to your doctor.
• Rashes and the presence of some symptoms, like vomiting or difficulty breathing, require emergency medical attention.

Developing a rash can be uncomfortable and cause anxiety for patients. Sometimes, rashes develop and disappear after one or two days. Other times, the rash may last longer or be accompanied by other symptoms. Some symptoms may indicate the presence of serious conditions and are best addressed at a hospital or emergency room.

Rashes that indicate a life-threatening illness are rare, but there are times when it is important to seek routine or emergency medical care for your rash. Knowing when to worry about a rash in adults can provide clarity on the next steps you should take to stay healthy.

When to seek immediate medical attention for a rash

Rashes representing life-threatening conditions are rare. However, it is important to know the signs and symptoms that can indicate such conditions.

1. You have a rash and a fever (temperature > 100.4 degrees Fahrenheit)

Fever and rash sometimes arise at the same time or follow one another. Some patients may have virus symptoms such as fever, fatigue, sore throat, or cough followed by a rash. This is known as viral exanthem and is often harmless.

If, however, you are experiencing a rash and a fever at the same time, you should get immediate medical attention. Some infectious diseases cause simultaneous fever and rash. Many are not life-threatening and can be observed. Others are serious and may require hospitalization.

2. You have a headache or are nauseous (with or without vomiting)

Headache is a common symptom of many viral infections. However, if you are experiencing headache, neck pain, vomiting, and a skin rash, seek emergency medical care. Those symptoms can indicate a life-threatening illness known as bacterial meningitis.

Bacterial meningitis is a rare cause of rash and headache/neck pain. The rash of bacterial meningitis looks like scattered purple/red dots or purple/red bruises. These do not disappear when you physically press on the skin.

A rash doesn’t always accompany the other symptoms of bacterial meningitis. So, if you or anybody you know is experiencing fever, headache, neck stiffness, or vomiting, please seek emergency care.

3. The rash involves your eyes, lips, mouth, or genitals

Rashes involving these parts of the body sometimes require treatment to prevent permanent damage.

Conditions such as shingles or Stevens-Johnson syndrome often involve the eyes, lips, mouth, or genitals. These are serious conditions, and patients need emergency medical care.

4. You are having trouble breathing or notice swelling of your face, tongue, or lips

Hives are a skin reaction often triggered by foods or other substances. Hives are considered an allergic reaction and can sometimes be accompanied by other serious symptoms.

These include swelling of the lips, face, or tongue and difficulty breathing. If you have trouble breathing or can feel your tongue, lips, or face swelling, seek emergency medical care.

5. The rash is spreading rapidly

A rash that spreads in a matter of hours requires medical attention immediately. This can represent a condition known as necrotizing fasciitis (flesh-eating disease).

If you are experiencing fever and a rapidly spreading painful rash, please seek emergency care. An allergic reaction (urticaria) can also cause a quickly spreading rash and should be evaluated at your local emergency department.

Read our full guides on rash symptoms and types of rashes for more.

When to schedule an appointment or see a specialist about a rash

While many rashes are not emergencies, some require input from a doctor. When in doubt, call your doctor and ask. Many times, rashes can be handled with a routine appointment.

1. Your rash lasts two days or more

Some rashes last longer than two days and then spontaneously disappear. That is not always the case, though, and it is important to determine whether your rash needs medical treatment.

Please call your doctor if your rash has been present for two days and is not showing signs of improvement.

2. The rash is covering most of your body

A rash that covers the entire body is sometimes due to more obvious causes, such as chickenpox.

Other causes include a viral infection or allergic reaction. Your doctor can help you determine the cause of the rash and initiate treatment.

3. The rash is blistering or turning into open sores

Rashes that blister or cause sores can indicate a viral infection, such as chickenpox, shingles, or genital herpes.

It can also indicate a severe condition such as Stevens-Johnson syndrome. This is usually a reaction to medication that starts with flu-like symptoms followed by a red rash that eventually blisters.

Because of the serious nature of these conditions, if you have a blistering rash or a rash that has turned into open sores, seek medical attention.

4. The symptoms are preventing you from completing normal daily activities

If you are experiencing severe itching or pain from your rash, please call your doctor. They may be able to prescribe medication or recommend at-home remedies that can reduce your symptoms.

As a side note, it’s important to avoid scratching your itchy rash. Scratching can further damage the skin, which often makes the itching worse.

Questions to ask your doctor about a skin rash

• Is it contagious?
• Can I do anything about the itching?
• What other signs or symptoms should I look out for?
• Is there anything I can do to prevent this from coming back?

If you're concerned about a child's rash, read our full guide on when to worry about a rash on children for more.

Frequently asked questions: when to worry about a skin rash in adults

It is normal to have questions about your symptoms. If you aren’t sure what to do about your rash, call your doctor for clarity.

How long should a rash last before seeing a doctor?

If your rash has lasted longer than two days, please contact your doctor. They may provide advice over the phone or want to see you in person.

How do you know if you need to see a doctor, go to the emergency room, or wait it out?

If you are having trouble breathing or are noticing swelling of the lips, face, or tongue, go to the emergency room. If the rash has spread over hours and is painful, go to the emergency room. If the rash involves your eyes, mouth, or genitals, go to the emergency room.

Most rashes do not require emergency care except for in the previously mentioned situations. If you call your doctor and explain your symptoms, they can usually schedule a routine appointment for you. If you are in doubt or are unsure, call anyway.

Final thoughts

Rashes are quite common, but life-threatening rashes are quite uncommon. If your rash seems to be responding to home treatment and doesn’t come with other severe symptoms, it’s likely nothing to worry about. If you are in doubt about your symptoms or are unsure what to do, call your doctor and ask.

General Medicine follows a strict editorial process, including using real experts to write our articles, vetted primary sources, fact-checking, a secondary medical review, and updates as necessary. This article was medically reviewed and fact checked by Dr. Lane Thaut, DO.

Sources

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Tsai, Jean, et al. “Skin rash in meningitis and meningoencephalitis.” Neurology vol. 80,19 (2013): 1808-11. doi:10.1212/WNL.0b013e3182918cda

Nair, Pragya A., and Bhupendra C. Patel. “Herpes Zoster (Shingles).” PubMed, StatPearls Publishing, 4 Sept. 2023, www.ncbi.nlm.nih.gov/books/NBK441824/.

Oakley, Amanda M., and Karthik Krishnamurthy. “Stevens-Johnson Syndrome (Toxic Epidermal Necrolysis).” PubMed, StatPearls Publishing, 10 Apr. 2023, www.ncbi.nlm.nih.gov/books/NBK459323/.

Kanani, Amin, Stephen D. Betschel, and Richard Warrington. "Urticaria and angioedema." Allergy, Asthma & Clinical Immunology 14 (2018): 1-13, https://aacijournal.biomedcentral.com/articles/10.1186/s13223-018-0288-z.

Wallace, Heather A, et al. “Necrotizing Fasciitis.” Nih.gov, StatPearls Publishing, 2019, www.ncbi.nlm.nih.gov/books/NBK430756/.

CDC. “Chickenpox.” Centers for Disease Control and Prevention, 2022, www.cdc.gov/chickenpox/about/index.html.

CDC. “About Genital Herpes.” Genital Herpes, 9 Apr. 2024, www.cdc.gov/herpes/about/index.html.

Zhao, Zhong-Qiu, et al. "Descending control of itch transmission by the serotonergic system via 5-HT1A-facilitated GRP-GRPR signaling." Neuron 84.4 (2014): 821-834.

“Home Remedies: What Can Relieve Itchy Eczema?” Www.aad.org, www.aad.org/public/diseases/eczema/childhood/itch-relief/home-remedies.