When to Worry About a Rash in Adults?

When you first see a rash on your skin, it’s normal to worry about whether or not it is dangerous or contagious. There are many different types of rashes, but they fall into two main categories: infectious rashes, and non-infectious rashes. Read on to learn more about how to identify rashes, and when to worry about them. 

Table of Contents

What Is a Rash?

A rash is an area of skin that is irritated, uncomfortable, itchy, swollen, and red. Rashes can have different textures. Sometimes they are raised, and sometimes bumpy or patchy. 

It’s important to note that a rash can look different depending on your skin color. If you have dark skin, a rash may look white or gray or darker than your surrounding skin usually does. On the other hand, rashes usually appear as pink, red, or even purplish for lighter skin tones.

There Are Many Reasons You May Develop a Rash. These Include:

  • Stress
  • Exposure to sun
  • Allergies
  • Underlying health conditions
  • Infectious diseases
  • Irritation from clothing
  • Reaction to medication

Most rashes are temporary, mild, and will clear up naturally on their own; however, there are certain times when it would be wise to see a professional about your rash.

What Diseases Have a Rash as a Symptom?

There are a variety of diseases that can cause a rash in adults. These include meningitis, staphylococcus infections, measles, herpes, insect bites, lupus, Lyme disease, shingles, HIV, and syphilis. Non-infectious skin disorders can also cause rashes. These include vitiligo, rosacea, eczema, and psoriasis, among others.

How Can You Tell if a Rash Is Serious?

When you have a rash, it can be itchy and uncomfortable. But the good news is that rashes are not serious or life-threatening most of the time. Rashes such as eczema, contact dermatitis, and psoriasis are uncomfortable, but they are not life-threatening or contagious.

Rashes are typically treated with over-the-counter remedies such as cortisone cream. However, some rashes are a cause for concern because they can signal a greater problem, such as a disease, infection, or allergic reaction.

When to Worry About a Rash in Adults?

  • When you have a fever with a rash: You should see a doctor right away or go to the emergency room if you have a fever and a rash simultaneously. The fever could indicate an infection such as measles, herpes, mononucleosis, shingles, or scarlet fever.
  • When the rash covers your whole body: When a rash covers a large portion of your body, it can be a sign of a severe allergic reaction or a serious infection that needs medical treatment. 
  • If you get blisters: You could be reacting to medication or having an allergic reaction if the rash consists of blisters or open sores.
  • If you are in pain: If you are in pain from a rash, it is important to get it checked out by a doctor as quickly as possible. Pain from a rash can signal an infection, such as shingles, which requires medical treatment. 
  • If the rash spreads quickly: When a rash spreads quickly, it can be a sign of an allergy. Occasionally, allergies can cause a severe reaction called anaphylaxis, which requires emergency medical treatment. If you have trouble breathing or experience swelling in your throat, call 911. Even if your rash is spreading slowly, however, it is still advisable to get it checked out by a doctor.
  • The rash has large purple patches: When you have a rash with dark bruises or large purple patches, it could signify that an infection is spreading within your body. Having large purple patches could indicate vasculitis, meaning your blood vessels are inflamed. It also could point to an issue with blood clotting.
  • You see bruises around the rash: If you have bruises surrounding a rash or within a rash, you may have been bitten by an insect.
  • Your rash is in the shape of a circle – A rash in the shape of a bullseye is a signifier that it was caused by Lyme disease, a disease carried by ticks. The sooner you get antibiotic medication for Lyme, the better your prognosis.
  • If the rash looks infected – A rash can become infected if you scratch it. Symptoms of infected rashes are green or yellow pus, warmth in the area, swelling or crusting, or red streaks. 

Types of Severe Rash in Adults

The Meningitis Rash

A rash from meningitis looks like small red “pinpricks” on the skin. However, as it develops, it turns into red or purple blotches.

Is it a meningitis rash? Try the glass test. A meningitis rash appears under the skin and is not raised, so to determine whether the rash is from meningitis, try pressing a clear drinking glass against it. If the rash marks are still visible, then it can be a good indicator that you should go to the emergency room. It’s important to note that it can be more challenging to spot a meningitis rash in those with darker skin.

Pemphigus Vulgaris (PV) Rash

PV is a type of autoimmune disease. PV typically occurs with oral lesions, followed by skin lesions (Popescu et al., 2019). According to Popescu et al. (2019), PV rashes start as blisters that can rupture, causing erosions and ulcers, leading to life-threatening infections. It is essential to get treatment because this disease can cause complications such as sepsis, electrolyte imbalances, and cardiac and renal failure. 

Stevens-Johnson Syndrome (SJS) Rash

SJS is a severe adverse reaction to a medication. It typically starts with flu-like symptoms, followed by a red or purple rash. The rash is painful and develops into blisters. The top layer of the skin sheds and begins to heal after a few days. According to Johns Hopkins Medicine (n.d.), Medications that can cause this rash are those that treat epilepsy and bipolar disorder, antibacterial sulfonamides, and even pain relievers such as Tylenol or Aleve.

Toxic Epidermal Necrolysis (TEN) Rash

TEN is a more severe version of SJS. It is life-threatening and requires hospitalization. Like SJS, it can be caused by certain antibiotics or anticonvulsants (Johns Hopkins Medicine, n.d.). This rash will peel in sheets, leaving large areas of raw flesh exposed. It is easy for these areas to become infected. 

Toxic Shock Syndrome (TSS) Rash

Toxic shock syndrome is a rare, life-threatening complication of a bacterial infection. A rash is one symptom of TSS, along with flu-like symptoms. The rash associated with TSS is flat and covers most body areas; it is described as similar to sunburn (Ross & Shoff, 2021). The skin sheds in large sheets, typically over the palms and soles of the feet. The rash symptoms typically occur a week or two following the onset of other symptoms. 

When to See a Doctor?

If you have signs of infection, a rash covering the whole body, are in pain, have open sores around the eyes, mouth, or genitals; or a quickly spreading rash or one accompanied by fever, visit a doctor.

You should never ignore a rash, because some rashes can be contagious, life-threatening, or indicate that you have an underlying health problem.

Get Help From an Online Doctor

Are you tired of waiting months to see a doctor? With the DrHouse app, you don’t have to wait. The DrHouse app allows you to connect with a board-certified doctor in less than 15 minutes.

As you can see, rashes can be severe, and they do not always disappear on their own without medical treatment. This is why it is critical to reach out to a doctor as soon as possible when you have an unknown rash.

During the video call with a DrHouse board-certified clinician, the clinician will quickly and efficiently identify your rash and determine the appropriate treatment. A DrHouse clinician will also be able to tell you whether your symptoms require immediate emergency care.

Telemedicine is the wave of the future. Seeing an online doctor is convenient and cost-efficient, and can provide you with quick access to professional help when time is of the essence.

With DrHouse, you can get medical prescriptions as well as an understanding of your symptoms and treatment. With the help of the DrHouse app, you will soon be on your way to a healthier life.

Key Takeaways

Rashes can be uncomfortable and itchy, and no one likes to get them. They are also very common, and everyone is likely to develop a rash at some point. There are two main categories of rashes: infectious and non-infectious. Non-infectious rashes such as eczema and psoriasis are more prevalent.

Rashes are commonly treated with OTC medications such as cortisone cream. Still, they sometimes require prescription medications such as lidocaine, or antiviral drugs like acyclovir (Zovirax), or certain types of antibiotics.

If you have a rash that spreads quickly, covers your whole body, or is accompanied by a fever, pain, or other disturbing symptoms, it’s crucial to quickly get in touch with a doctor. This is where the help of DrHouse comes in. With DrHouse, you can see a board-certified doctor in as little as 15 minutes.


Content on the DrHouse website is written by our medical content team and reviewed by qualified MDs, PhDs, NPs, and PharmDs. We follow strict content creation guidelines to ensure accurate medical information. However, this content is for informational purposes only and not a substitute for professional medical advice, diagnosis, or treatment. For more information read our medical disclaimer.

Always consult with your physician or other qualified health providers about medical concerns. Never disregard professional medical advice or delay seeking it based on what you read on this website.

If you are experiencing high fever (>103F/39.4C), shortness of breath, difficulty breathing, chest pain, heart palpitations, abnormal bruising, abnormal bleeding, extreme fatigue, dizziness, new weakness or paralysis, difficulty with speech, confusion, extreme pain in any body part, or inability to remain hydrated or keep down fluids or feel you may have any other life-threatening condition, please go to the emergency department or call 911 immediately.



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