What is a Skin Rash?
A skin rash can be described as when the skin becomes red, swollen or irritated. In some instances red bumps or blisters can also appear.
There are multiple reasons why people experience a skin rash. Some can be brought on through contact at the surface, whereas other instances could indicate a problem inside the body.
Skin rashes are very common, most people are likely to develop one at some point during their lifetime. In fact, a rash caused by an irritant or allergen is very common. (1)
Causes
The skin is the front line of defence for the body. However, it does much more than just package up our insides. It also contains tissue tuned into the immune system for added protection. This means when irregularities are detected it will spark a chain reaction thus causing a rash.
Below are some poignant causes of skin rash:
Heat Rash (Prickly Heat)
A heat rash is caused by excessive sweating. The sweat glands become blocked and it traps moisture inside which can result in a rash. (2)
It typically appears as bumps, blotches or spots that feel itchy or prickly. This can later become red and swollen.
Eczema
Eczema is the name for a group of different skin conditions which causes inflammation.
It does normally affect younger children of which they usually outgrow it before reaching adulthood. However, to some people, eczema can become chronic.
There are many types of eczema. But the most common is atopic dermatitis.
Atopic dermatitis is a skin disease which causes the skin to become extremely itchy. When the person scratches, it causes redness and swelling which can lead to fluid filled blisters that later rupture.
Atopic dermatitis isn’t a persistent condition, it has the tendency to flare up, then symptoms will subside for a time. (3)
Contact Dermatitis
This is another type of eczema, of which there are two types: allergic contact and irritant contact.
Allergic contact is when the skin comes in contact with an allergen. For example, pets, perfumes, or nickel. (4)
An allergic rash is usually red and itchy, where sometimes small blisters or bumps can appear. It may also not show straight away after initial contact with the allergen. (5)
Irritant contact is when the skin becomes inflamed by friction or rubbing of a harsh substance.
Chickenpox
Chickenpox is an infection predominantly developed by children. It’s highly contagious and displays a classic sign of a red, itchy blister filled rash.
It usually starts with a fever and flu like symptoms then progresses into a rash. This will generally run its course within a couple of weeks. (6)
Shingles
This condition is caused by the same virus as chickenpox. After the rash subsides, the virus stays dormant in the body and can cause a relapse years later.
Shingles will cause a painful blistering rash, typically affecting one side of the body or face. The rash will usually clear up within two to four weeks.
People with a weakened immune system or who take immunosuppressive drugs are at a higher risk for shingles. (7, 8)
Psoriasis
This is considered a condition which causes areas of the skin to appear scaly and swollen which can feel painful and hot.
People with psoriasis present a higher risk of developing cardiovascular complications or psoriasis arthritis, which causes pain in the joints. (9)
Systemic Lupus Erythematosus (lupus)
Lupus is a complicated disorder, it causes the immune system to attack healthy tissues and cells instead of an infection or virus.
This condition can cause a red rash on the face along with other symptoms including: muscle ache, high temperature and joint swelling. It’s also common for the symptoms to come and go.
The disorder is not contagious, but anyone can be affected. However, women generally develop it more often than men. (10)
Measles
Measles is a viral and highly contagious condition. It’s normally seen in children, but it can also affect adults.
It brings about a red-brown color rash that starts behind the ears and then spreads to the head and neck before continuing down the body.
The rash presents alongside a fever, aching body and a cough, yet it generally resolves itself within a week. (11)
However, measles can lead to complications. It’s estimated that one out of 1000 children with the virus will die from it. (12)
Drug Rash
There are some types of medicines which can cause a ‘drug rash’. It’s basically an allergic reaction to the drug which causes the flare up.
It is very important to contact your doctor if you experience this type of symptom after commencing a new form of treatment. A rash can point towards a severe allergic reaction. (13)
Meningitis
This condition is mostly seen in children and young adults, but it can affect anyone. It causes an infection around the membranes of the brain and spinal cord.
Along with a fever, nausea and body aches, the most distinct indication of meningitis is a rash, which when pressed with a glass does not go away.
At first it will cause small red pin pricks which will spread quickly and form a blotchy rash that can appear red or purple in color. (14)
If you suspect meningitis It’s crucial to seek urgent medical attention.
Symptoms
Symptoms of a skin rash presents a multitude of signs. They come in all shapes, sizes and colors. (15, 16, 17, 18)
A skin rash can sometimes be blotchy, scaly or even spot like. It could also appear raised from the skin or completely flat to the surface.
You might find it concentrated in one specific area, like the elbows or it could spread over the entire body.
The intense desire to scratch or itch the skin rash is a common symptom.
The skin often becomes dry and irritated in the early stages of a skin rash and this will often be a cause of the sensation.
However, scratching the rash can lead to further implications, resulting in blisters, redness, swelling, cracking or scaling.
If persistent scratching continues the blisters will rupture and leak fluid causing the skin to be left exposed. If not handled properly it could lead to further inflammation or infection.
A skin rash accompanied with fever like symptoms could be a sign of an infectious disease. (19)
Furthermore, anyone experiencing hair loss with a skin rash could indicate a sign of the more serious conditions such as psoriasis and lupus. (20,21)
Diagnosis
Because a skin rash is typically a symptom of other conditions, doctors generally start by asking a few questions, followed by an examination.
If there is reason to believe allergies are involved, they may even expose a small area of the skin to tiny amounts of allergens to determine the cause.
If an obvious diagnosis is not apparent, your doctor may refer you to a dermatologist or allergist who specializes in skin conditions.
Below are some common questions a doctor might ask you.
History
Your doctor will most likely start out by asking you a series of questions about your family medical history. (22)
Questions may include: any allergies or any diseases which can cause a rash, for example hay fever or asthma.
Exposure to Irritants
Next your doctor might ask if any recent exposure to the following as taken place: wool or synthetic fibers, new detergents or soaps, maybe a special perfume, dust or sand, even cigarette smoke. Lastly, whether exposure to chemicals have taken place. (23)
Diet
Some people are allergic to certain types of food without knowing it. A rash following a new ingredient in your diet might help pinpoint the cause.
Present Medication
Your doctor might check to see if you’ve had prior treatments for skin related symptoms or if you’re currently on any steroids or other medication. (24)
Prick Test
If your doctor suspects an allergy, a prick test might be used. (25)
In the prick test your doctor will expose an area of your skin to a tiny amount of different allergens. Any which create a reaction indicates what you’re allergic to.
Further Diagnosis
In case your doctor suspects an underlying issue, a sample from your rash might be taken to a lab for further analysis. (26)
If an infection is suspected, blood samples might be done to secure the right treatment.
FAQ
What is a skin rash? A skin rash is an inflammation of the skin which can cause redness, irritation or swelling, blisters or sores.
What causes a skin rash? Skin rashes can have many different causes. The most common include, eczema or allergies.
How do doctors test for skin rash? If it’s a possible allergic reaction the doctor might do a prick test, in other cases a sample from the rash could be taken for further tests.
When should you go to the doctors with a skin rash? If the rash hasn’t gone away after a few days or causes persistent discomfort. If it appears to be spreading, especially to the face or if it looks infected or coincides with a new form of medication. (27)
Can you prevent skin rash? Yes by keeping your skin healthy, using sunscreen and avoiding triggers like allergens and foods that you are sensitive towards. However, some rashes which accompany certain illnesses cannot be prevented.
What can relieve a skin rash? Moisturizing creams or lipid-replenishing treatments will usually relieve a rash. You can also obtain soaps, cleansers and shampoos which are designed for those with sensitive skin. They are milder or unperfumed and shouldn’t dry out the skin causing irritation. Medicines such as antihistamines can help relieve itching. (28)
Will the skin return to normal after a skin rash? In most cases the skin should return to normal after the rash has subsided. However, scratching the rash is the biggest cause of scarring. Therefore it’s important to try and refrain from this action no matter how much irritation is caused.
Are steroid creams safe to use? Yes steroid creams are typically safe to use, unless your doctor tells you otherwise. Steroid creams can help relieve itchiness and inflammation surrounding the rash. (29)
Summary
A skin rash is an area of skin which has become inflamed and likely to become red, itchy or irritated.
It’s clear a skin rash can be a telltale sign of a number of different medical situations from the mild to the extreme.
A rash can be a classic sign of too much sun or heat exposure, which in itself can be avoided. The same could be said for allergic reactions and irritants.
However we have also seen a skin rash is a sign of illnesses like chicken pox, measles and shingles or chronic skin conditions.
A skin rash may seem like an minor irritation to many, yet in the case of meningitis a rash is a main indicator something is very wrong. Therefore, early detection could save your life.