What causes red spots on legs? Related conditions and treatments

Overview: What do red spots on legs look and feel like?

Red spots can appear on any part of the body, including the legs. Most of the time, these spots are temporary and usually harmless. The spots could be small, large, flat, raised, or a nodule like a pimple. There could be one spot, a few spots, or they could be densely clustered. They might appear smooth, dry, bumpy, or scaly. Sometimes the spots may itch or burn.

What causes red spots on legs?

There are many causes of red spots on the legs. Some can be serious, but most are only temporary and usually no more than an inconvenience.

Dermatitis

The most common cause of red spots on legs is dermatitis, a non-specific term referring to any condition that causes the skin to turn red, swell, itch, or get covered in a rash. The two most common types of dermatitis that cause red spots on the legs are contact dermatitis and eczema.

Contact dermatitis

Red spots, rashes, skin redness, swelling, and itchy skin can be due to contact with an irritant, chemical, or allergen such as:

• Insect bites, flea bites, tick bites, and scabies

• Poison plants such as poison ivy or poison oak

• Chemicals or solvents

• Soaps, shaving lotion, detergents, or similar allergens

RELATED: How to treat contact dermatitis

Eczema

Eczema (atopic dermatitis) is a common skin condition that can cause skin redness, rash, and itchy skin. Eczema is associated with dry skin and is thought to have a wide variety of triggers, including:

• Skin irritants

• Hormones

• Inhaled allergens

• Stress

• Weather

• Foods

RELATED: Which eczema treatment is right for you?

Hives

Hives are very similar to contact dermatitis and can affect the skin on any part of the body. It causes itchy, red, swollen welts on the skin. Hives can be triggered by inhaled allergens, foods, medications, stress, or seemingly nothing at all. Outbreaks are usually brief—a few hours to less than a day.

RELATED: What to do when exercise triggers hives

Heat rash

Heat rash is a common reaction to hot temperatures or intense exercise. Caused by blocked sweat glands, heat rash appears as tiny, swollen red spots. It can occur anywhere on the skin, including the legs.

Infections

Red spots on the legs may be a sign of a skin infection, including:

• Folliculitis

Folliculitis occurs when hair follicles swell up and become red. It’s often due to a bacterial infection, but not always. One or several hair follicles can be involved, producing multiple brownish-red nodules.

• Ringworm

Ringworm, or tinea corporis, is not caused by a worm at all but rather is a fungal infection of the skin similar to athlete’s foot.

• Pityriasis rosea

A common viral infection of the skin, pityriasis rosea primarily affects the chest and back. It usually appears as a large patch on the trunk, eventually surrounded by other red or brownish-red patches. These patches can spread to the arms and legs.

• Cellulitis

Cellulitis is a common bacterial infection of the skin that usually appears as a large red or brown swollen area, but can also look like a dense rash in some cases. The lower legs are commonly affected.

• Chickenpox

A type of herpes infection that primarily afflicts young, unvaccinated children, chickenpox causes an itchy, red rash that mostly affects the face, trunk, and scalp. If the rash spreads to the legs, the rash in this location is usually minimal compared to the rest of the body. 

Blood vessel problems

Red spots on the legs may be due to blood vessel problems, particularly the tiniest blood vessels in the leg, called capillaries. These include:

• Vasculitis

Vasculitis is an autoimmune disorder in which the immune system attacks blood vessels and causes them to swell. One of the most common symptoms is a dense rash of red to dark red spots on the lower legs. Vasculitis can be a serious medical condition that can be life-threatening.

• Capillaritis

Capillaries are the smallest blood vessels in the body. Capillaritis occurs when they leak blood and fluid near the skin, causing harmless purple to purple-red flat spots. Capillaritis can affect any part of the body but usually affects the legs and arms.

• Angiomas

Angiomas are harmless capillary growths that appear as ruby-red to dark purple spots (cherry angiomas) or diffuse red spots with lines radiating out from the center (spider angiomas). They can appear anywhere on the skin.

• Petechiae

Petechiae are harmless tiny, cherry-red, or red dots that appear when capillaries near the surface of the skin break and bleed out. They have many causes, including heavy lifting, heavy exercise, sunburn, scrapes, aging, or side effects from medications.

Other skin problems

Other conditions that can cause red spots on the legs include:

• Keratosis pilaris

A common and harmless skin condition, keratosis pilaris causes tiny red bumps or rough patches on an entire patch of skin, usually the arms, thighs, or cheeks. 

• Psoriasis

Psoriasis is an autoimmune condition in which the immune system primarily attacks the skin and other tissues. During flare-ups, people commonly experience scaly, swollen rashes that can affect any area of the body, including the legs. 

• Lichen planus

Lichen planus is an immune system reaction that can cause itchy skin rashes composed of tiny purple papules. These rashes usually break out on the wrists, hands, and lower legs but can appear anywhere on the skin. Half of people with lichen planus also get rashes of white spots inside of their mouth and tongue during a flare-up.

• Skin cancer

Skin cancers may appear as a red or dark spot or nodule on the skin. They can appear flat, raised, or bumpy. Skin cancers can develop anywhere on the body. 

• Dermatofibroma

A dermatofibroma is a harmless skin tumor that can be easily mistaken for a more serious skin cancer. It usually appears as a single dark red or purple nodule on the skin. A dermatofibroma can appear anywhere on the skin.

RELATED: What are the early signs of psoriasis?

Should I be worried about red spots on the legs?

In most cases, red spots on the legs are not a cause for worry. Many causes of red spots are benign, temporary, or both. Many causes of red spots on legs, such as bug bites, heat rash, or cherry angiomas, don’t require any medical treatment. Others only require symptomatic treatment, like poison ivy, eczema, lichen planus, or pytiriasis rosea. 

Some causes may be potentially serious, like allergic reactions or hives, because they could evolve into a more serious allergic reaction. Get urgent medical care if you notice symptoms such as trouble breathing, trouble swallowing, throat swelling, lightheadedness, or low blood pressure.

Some causes of red spots are serious conditions such as cellulitis, vasculitis, and skin cancer. Both cellulitis and vasculitis will have other symptoms and are usually marked by either dense rashes or discoloration of an entire area of skin. They will most likely have other symptoms as well, such as fever, trouble breathing, coughing, and fatigue. Skin cancer appears as a single red, brown, or dark lesion. You should bring any new growth on the skin to the attention of a healthcare provider.

How are the causes of red spots on legs diagnosed?

A healthcare provider will typically diagnose red spots by examining the skin, taking a medical history, and maybe conducting a more complete physical exam or skin exam. Depending on the cause, the clinician may refer the case to a dermatologist, allergist, or rheumatologist. In many cases, however, a primary care provider can diagnose the cause and send people home with medical advice or prescription medications. For allergic reactions, an allergist may use a series of allergy tests to discover specific allergies.

More serious conditions, such as autoimmune diseases or cancer, will require more diagnostic tests by a specialist. This could involve blood tests and taking a skin sample for biopsy.

Are red spots on legs contagious? 

If red spots or rashes are caused by a fungal infection, that infection can be spread by skin-to-skin contact or contaminated surfaces, clothing, or towels.

How long do red spots on legs last?

Depending on the causes, red spots on the legs can last a few hours or a few days or be a recurrent or chronic problem. Some red spots, like cherry angiomas, are lifelong but harmless blemishes unless they’re surgically removed. 

How to stop red spots on legs

Red spots on legs treatments will vary depending on the underlying cause. Treatment options for the most common causes of red spots are mostly home remedies:

• Contact dermatitis is usually treated at home with anti-itch medications, steroid creams, calamine lotion, and sometimes oral antihistamines.

• Eczema can also be treated at home with gentle skincare, gentle cleaning, moisturizing lotions, and anti-itch creams—in some cases, prescription medications may be needed.

• Heat rash can be treated at home with cold compresses, calamine lotion, ointments, or anti-itch creams.

• Hives are usually treated with oral antihistamines and anti-itch creams, usually containing a corticosteroid. Medical treatment may be necessary for a more serious allergic reaction. Prescription immune suppressants may be used to manage chronic hives.

• Keratosis pilaris can also be treated at home with moisturizers, anti-itch medications, and keratolytics (medicines that strip away dead skin).

• Folliculitis is usually managed with home treatments like warm compresses, anti-itch creams, and keeping the affected area clean. In severe cases, a healthcare professional may use prescription medications.

What’s next? Additional resources for people with red spots on legs

Test and diagnostics

• Atopic dermatitis: diagnosis and treatment, American Family Physician

• Contact urticaria, StatPearls

• Diagnosis and management of contact dermatitis, American Family Physician

• Lichen planus, Cleveland Clinic

• Rashes affecting the lower legs, DermNet