What Causes Blotchy Skin?

Most of us have experienced an uneven skin tone, known as blotchy skin, at some point. Blotchy skin appears as patches of discolored skin that can be red, purple, or blue. Many causes of blotchy skin are temporary and brought on by environmental factors or exposure to irritating substances. Others, however, are serious health conditions that need to be addressed.

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Temperature

Changes in temperature can lead to changes in blood circulation in the body. When this occurs, the skin color may be altered in response to either more or less blood flow. Our skin can also change color due to sun damage.

Sunburn

You have most likely experienced a sunburn in your life. The inflammation and redness lead to a blotchy appearance. This change in color is due to sun damage to the skin. Excessive sun exposure without ultraviolet (UV) protection damages the skin cells and leads to accelerated skin aging. The blotchy redness is a result of inflammation responding to the damage.

Heat Rash

Heat rash first appears as a fine pink rash along the neck, chest, and upper back. The rash looks like tiny pink bumps. It’s more common in children and can occur after spending time outdoors in the heat or engaging in strenuous activity. Heat rash can also cause pain, itching, and a “pins and needles” feeling. 

Exposure to Cold

When you first walk out into cold weather, the blood vessels in your skin narrow, or constrict. This happens to minimize heat loss from the body. This vasoconstriction can lead to changes in the skin’s appearance, including paleness and blue mottling. The discoloration resolves on its own once your body warms up.

While not as common, some individuals experience blotchy skin in the cold weather due to hives. Hives, also known as urticaria, are welts on the skin that can occur from an allergic reaction or as a result of cold weather. Hives appear as blotchy, red skin and can lead to itching and pain.

Is Exercise Causing Your Blotchy Skin?

Exercise is healthy for just about everyone, but in rare cases, it can cause health issues. Because exercise heats up the body, it’s possible to experience blotchy skin from heat rash during or immediately after your workout. This usually only occurs with very strenuous activities.

It’s also possible to experience exercise-induced urticaria. Symptoms include raised red welts, blotchy red skin, and itching with exercise. Rarely, life-threatening reactions such as anaphylaxis can occur. If you suspect exercise is causing your hives, talk with your allergist about using antihistamines or other medications to help. 

Allergies

Skin changes like blotchy skin are common in allergic reactions. Skin reactions can be temporary in the case of hives or chronic such as with eczema. 

Hives

About 20% of us will experience hives at some point in our lives. Hives appear as red welts and are brought on by an allergic reaction. These welts are large raised bumps on the skin. They are usually red, very itchy, and can be blanched, which means that the center turns white when you press on it.

You can get hives when your body reacts to an allergen such as specific foods, plants, medications, or infections. Most cases of urticaria are temporary, but they can become chronic. If you ever experience hives along with difficulty breathing or a feeling that your throat is closing up, seek emergency medical help. 

Contact Dermatitis

Contact dermatitis occurs when our skin reacts to being in contact with a substance that triggers a reaction. It happens in about 15%–20% of people, and results from an allergic reaction or irritation. Contact dermatitis appears as blotchy, red skin and an itchy rash. 

Contact dermatitis may be caused by a hypersensitivity to common household items like soap, laundry detergent, or perfume. The rash appears where skin is exposed to the irritant. Allergens that can cause contact dermatitis include plants like poison oak and poison ivy and certain foods and medications. 

Eczema

Eczema, also known as atopic dermatitis, is a common cause of blotchy skin and affects over 31 million Americans. It includes a group of skin conditions that cause itchy red patches of skin. Other symptoms of eczema include dry skin, inflammation, skin thickening, and oozing sores. 

Eczema is caused by an allergic response in the body, but researchers do not know why some people develop it while others do not.

Hereditary Conditions

Blotchy skin and uneven skin tone can be caused by conditions you inherit. For example, some people's skin genetically produces more melanin and becomes darker as a result of certain conditions such as Addison’s disease. It can also become lighter in conditions like vitiligo (smooth white patches of skin) and albinism (skin that has little or no pigment). If you notice the discoloration over time, see your healthcare provider.

Stress

Stress is the last thing you need when you are faced with a new health problem. Unfortunately, extreme stress can manifest in our bodies and on our skin. Stress can lead to a rash or hives that are red and itchy. Burning and pain are also possible. A rash of hives from stress can happen to anyone, but rashes are more common in those who have a history of urticaria.

It’s possible for this blotchy skin brought on by stress to last for weeks. If you can’t seem to get a handle on the symptoms, talk with your healthcare provider about treatment options and long-term stress-management techniques. 

Rosacea

Rosacea is a common skin condition that affects about 14 million Americans. It usually starts as a tendency to blush easily. Other symptoms include redness, acne-like breakouts, irritated skin, visible blood vessels, sensitivity to the sun, and inflammation.

The exact cause of rosacea is unknown, but it seems to be related to the immune system. Individuals with fair skin and light-colored eyes and hair are more at risk for rosacea, as are people between 30 and 50 years old. A family history of rosacea and a history of acne can also put you at greater risk. 

Sun Protection for Blotchy Skin

While anyone's skin can be damaged by the sun, people with sensitive skin prone to blotchiness are at higher risk. Once your skin is already irritated, sun exposure can worsen redness, inflammation, and pain. 

Protect your skin by covering it up in the sun, staying in the shade outdoors, applying sunscreen every morning, and avoiding tanning beds.

Scarlet Fever

Scarlet fever, also known as scarlatina, is caused by group A Streptococcus bacteria and can affect the appearance of the skin. In addition to fever and chills, scarlet fever can cause a red bumpy rash about one to two days after the infection starts. The rash usually starts out as flat blotches on the skin that eventually become raised. It usually appears on the neck and in the underarms and groin area.

Shingles

Shingles is caused by the herpes zoster virus that causes chickenpox and leads to a painful rash and blotchy skin. More than 1 million Americans are diagnosed with shingles each year. Symptoms of shingles include:

  • Pain
  • Burning
  • Blisters
  • Tingling or an “electrical” sensation

Shingles can also cause a fever, headache, muscle pain, and vomiting. The virus will clear up on its own, but you can manage the pain and symptoms with treatments. Shingles can recur once it has resolved, so it’s important to talk with your healthcare provider about the shingles vaccine for older adults and if it’s right for you.

Pregnancy

It is not uncommon for pregnancy to change your skin tone. The hormones and other changes your body goes through during pregnancy can affect your skin and may lead to a common condition known as melasma. Melasma, sometimes called the mask of pregnancy, causes brown patches on your face, usually affecting the neck, bridge of the nose, forehead, and chin. It may be caused by the hormonal changes experienced during pregnancy and can worsen from sun exposure. Melasma usually fades on its own after pregnancy.

Alcohol Flush Syndrome

If you have ever felt your cheeks and neck flush after a few sips of a cocktail, you may have experienced alcohol flush syndrome. This syndrome signals an intolerance to alcohol, which is an inherited metabolic condition. Alcohol intolerance can cause skin redness, flushing, itching, and swelling. Other symptoms can include nausea and vomiting, rapid pulse, low blood pressure, headache, and diarrhea. 

Alcohol intolerance is caused by a lack of an enzyme that our bodies use to metabolize alcohol. Alcohol flush syndrome can be prevented by avoiding alcohol.

A Word From Verywell 

Blotchy skin is a change in skin color due to a reaction or condition. While most causes of blotchy skin can be managed at home, there are rare cases that signal a life-threatening emergency. When the body experiences shock, for example, blotchy, mottled skin may be the first sign. Shock includes other concerning signs such as difficulty breathing, rapid heartbeat, and weakness.

Much of the time, skin blotches are temporary, but always check with your healthcare provider if you are concerned about a new change in your skin color. If your blotchy skin is accompanied by more serious symptoms like difficulty breathing, seek emergency treatment right away.

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12 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Skin Cancer Foundation. Sunburn & Your Skin. Updated June 2019.

  2. Seattle Children’s Hospital. Heat Rash. Updated August 14, 2020.

  3. American Academy of Dermatology Association. Welts on skin due to cold temperature could be hives.

  4. Familydoctor.org. Exercise-induced Urticaria. Updated June 15, 2020.

  5. American Academy of Allergy, Asthma and Immunology. Hives (Urticaria). Updated June 11, 2018.

  6. American Academy of Allergy, Asthma and Immunology. Contact Dermatitis. Updated September 28, 2020.

  7. National Eczema Association. Eczema Symptoms & Causes. Updated 2021.

  8. Medline Plus. Skin Pigmentation Disorders. Updated November 6, 2020.

  9. American Academy of Dermatology Association. Is rosacea causing your red, irritated skin?

  10. Centers for Disease Control and Prevention. Scarlet Fever: All You Need to Know. Updated November 1, 2018.

  11. American Academy of Dermatology Association. Shingles: Diagnosis and treatment. Updated 2021. 

  12. Cleveland Clinic. Alcohol Intolerance. Updated August 24, 2020.