Redness on the upper legs is most often seen as a rash on the thighs. This condition can be caused by contact dermatitis, or an allergic reaction from certain bugs or plants. Cellulitis can also cause a red rash on the upper thigh. Read on for more information about causes and relief options.
9 most common cause(s)
7 causes of upper leg redness
This list does not constitute medical advice and may not accurately represent what you have.
Squamous cell carcinoma
Squamous cell carcinoma (SCC) is a type of skin cancer. The most common spots for this cancer are the head (including scalp, lips, ears, and mouth), legs, and the backs of the hands and the arms. It appears on the skin as a tiny, painless bump or patch. The main risk factor for developing this condition is prolonged exposure to ultraviolet (UV) radiation. Sun exposure and tanning beds are both sources of UV radiation. People with a history of sunburns, previous skin cancer, and a weakened immune system are at higher risk for this condition.
Most cases of SCC can be easily treated because they grow slowly. However if not treated, it can spread inside the body. Your provider will do a skin exam and possibly a skin sample test, known as a biopsy. Treatment will depend on where the cancer is, its size, and your medical history. Some treatment options include cutting out the bump, freezing it, or using medicated skin cream.
Rarity: Uncommon
Top Symptoms: worsening face redness, rough skin on the face, scabbed area of the face
Urgency: Primary care doctor
Skin abscess
A skin abscess is a large pocket of pus that has formed just beneath the skin. It is caused by bacteria getting under the skin, usually through a small cut or scratch, and beginning to multiply. The body fights the invasion with white blood cells, which kill some of the infected tissue but form pus within the cavity that remains.
Symptoms include a large, red, swollen, painful lump of pus anywhere on the body beneath the skin. There may be fever, chills, and body aches from the infection.
If not treated, there is the risk of an abscess enlarging, spreading, and causing serious illness.
Diagnosis is made through physical examination.
A small abscess may heal on its own, through the body's immune system. But some will need to be drained or lanced in a medical provider's office so that the pus can be cleaned out. Antibiotics are usually prescribed.
Keeping the skin clean, and using only clean clothes and towels, will help to make sure that the abscess does not recur.
Rarity: Common
Top Symptoms: rash with bumps or blisters, red rash, red skin bump larger than 1/2 cm in diameter, pus-filled rash, rash
Symptoms that always occur with skin abscess: rash with bumps or blisters
Urgency: Primary care doctor
Non-specific thigh rash
A rash is an area of irritated or swollen skin. Often, rashes are unidentifiable and some variation of normal. For example, scratching one's arm causes it to turn red (which is caused by mast cells releasing chemicals into the local area), but that's completely normal.
At this time, you do not need treatment for this rash. If it worsens, you may need to consult a physician.
Necrotizing fasciitis of the leg
Necrotizing fasciitis is a potentially life threatening skin condition stemming from the infection of a wound or injury. If left untreated, it can spread to body parts surrounding the infection changing the color of the skin and degrading the tissue underneath. This can result in muscle, tissue, or limb loss and a severe body-wide response to the infection.
You should visit your local emergency room where blood tests can be run and a consultation can be made by a skin specialist. If caught early, antibiotics, cleaning, and a stay in the hospital can help control the infection. If serious, additional procedures may be required. It is important to get treatment due to the possibility of this becoming a serious, life-threatening condition.
Rarity: Ultra rare
Top Symptoms: nausea, diarrhea, vomiting, fever, chills
Symptoms that always occur with necrotizing fasciitis of the leg: leg skin changes
Urgency: Hospital emergency room
Molluscum contagiosum
Molluscum contagiosum, also called "water warts," is a common, benign, viral skin infection. It causes a rash of bumps that may appear anywhere on the body.
The virus spreads through direct contact with the bumps, including sexual contact. It also spreads through touching any object that an infected person has handled, such as clothing, towels, and toys.
Most susceptible are children under age 10. Other risk factors include dermatitis causing breaks in the skin; a weakened immune system; and living in warm, humid regions under crowded conditions.
Symptoms include a rash of small, pale bumps with a pit in the center. The rash is usually painless but may become reddened, itchy, and sore.
Diagnosis is made through physical examination.
In some cases, treatment is not needed and the condition will clear on its own. However, if the bumps are unsightly or are present in the genital area, lesions can be removed through minor surgical procedures or treated with oral medication or topical agents.
Irritant contact dermatitis
Irritant contact dermatitis means a skin reaction that is caused by directly touching an irritating substance, and not by an infectious agent such as a bacteria or virus.
Common causes are soap, bleach, cleaning agents, chemicals, and even water. Almost any substance can cause it with prolonged exposure.
Contact dermatitis is not contagious.
Anyone who works with an irritating substance can contract the condition. Mechanics, beauticians, housekeepers, restaurant workers, and health care providers are all susceptible.
Symptoms include skin that feels swollen, stiff, and dry, and becomes cracked and blistered with painful open sores.
A medical provider can give the best advice on how to heal the skin and avoid further irritation. Self-treatment can make the problem worse if the wrong creams or ointments are used.
Diagnosis is made through patient history, to find out what substances the patient comes into contact with, and through physical examination of the damaged skin.
Treatment involves avoiding the irritating substance if possible. Otherwise, the person can use petroleum jelly on the hands underneath cotton and then rubber gloves.
Rarity: Common
Top Symptoms: rash with well-defined border, itchy rash, red or pink, rough patch of skin, painful rash, red rash
Symptoms that always occur with irritant contact dermatitis: rash with well-defined border
Symptoms that never occur with irritant contact dermatitis: fever, black-colored skin changes, brown-colored skin changes, blue-colored skin changes
Urgency: Self-treatment
Eczema (atopic dermatitis)
Atopic dermatitis, also called eczema, dermatitis, atopic eczema, or AD, is a chronic skin condition with an itchy rash.
AD is not contagious. It is caused by a genetic condition that affects the skin's ability to protect itself from bacteria and allergens.
AD is most often seen in infants and young children. Most susceptible are those with a family history of AD, asthma, or hay fever.
Infants will have a dry, scaly, itchy rash on the scalp, forehead, and cheeks. Older children will have the rash in the creases of elbows, knees, and buttocks.
Without treatment, a child may have trouble sleeping due to the intense itching. Constant scratching may cause skin infections and the skin may turn thickened and leathery.
Diagnosis is made through physical examination, patient history, and allergen skin tests.
AD cannot be cured but can be controlled through prescribed medications, skin care, stress management, and treatment of food allergies. Those with AD often have allergies to milk, nuts, and shellfish. Keeping the skin clean and moisturized helps prevent flare-ups.
Cellulitis
Cellulitis is a bacterial infection of the deep layers of the skin. It can appear anywhere on the body but is most common on the feet, lower legs, and face.
The condition can develop if Staphylococcus bacteria enter broken skin through a cut, scrape, or existing skin infection such as impetigo or eczema.
Most susceptible are those with a weakened immune system, as from corticosteroids or chemotherapy, or with impaired circulation from diabetes or any vascular disease.
Symptoms arise somewhat gradually and include sore, reddened skin.
If not treated, the infection can become severe, form pus, and destroy the tissue around it. In rare cases, the infection can cause blood poisoning or meningitis.
Symptoms of severe pain, fever, cold sweats, and fast heartbeat should be seen immediately by a medical provider.
Diagnosis is made through physical examination.
Treatment consists of antibiotics, keeping the wound clean, and sometimes surgery to remove any dead tissue. Cellulitis often recurs, so it is important to treat any underlying conditions and improve the immune system with rest and good nutrition.
Rarity: Uncommon
Top Symptoms: fever, chills, facial redness, swollen face, face pain
Symptoms that always occur with cellulitis: facial redness, area of skin redness
Urgency: Primary care doctor
Allergic reaction to poison ivy/oak/sumac
Plants of the Toxicodendron genus are found throughout the continental United States, and exposure to these plants is a leading cause of contact dermititis, a medical term used to describe irritation and itching of the skin.
Firstly, to prevent allergic reaction to poison ivy from getting worse, wash the affected area thoroughly with soap and water. Over-the-counter antihistamines such as Benadryl can help with the swelling and itching. Topical corticosteroids applied directly to the rash can also help relieve some of your symptoms
Rarity: Common
Top Symptoms: rash, itchy rash, red rash, skin changes on arm, stinging or burning rash
Symptoms that always occur with allergic reaction to poison ivy/oak/sumac: itchy rash, rash
Symptoms that never occur with allergic reaction to poison ivy/oak/sumac: fever
Urgency: Self-treatment
Allergic contact dermatitis of the thigh
Allergic contact dermatitis is a condition in which the skin becomes irritated and inflamed following physical contact with an allergen. Common products known to cause allergic dermatitis include plants, metals, soap, fragrances, and cosmetics.
Rarity: Common
Top Symptoms: upper leg itch, upper leg redness, scabbed area of the upper leg
Symptoms that always occur with allergic contact dermatitis of the thigh: upper leg redness
Urgency: Self-treatment
Questions your doctor may ask about upper leg redness
- Do you have a rash?
- Is the red area flaky and rough to the touch?
- Did your symptoms start after you were exposed to glues, fragrances, preservatives, hair dyes, soaps, detergents, or other common household chemicals?
- Did your symptoms start after you were exposed to nickel (commonly found in jean snaps, metal pens, paper clips, cigarettes, etc.)?
Self-diagnose with our free Buoy Assistant if you answer yes on any of these questions.
Upper leg redness symptom checker statistics
People who have experienced upper leg redness have also experienced:
- 7% Lower Leg Redness
- 5% Knee Redness
- 4% Foot Redness
People who have experienced upper leg redness were most often matched with:
- 66% Cellulitis
- 16% Irritant Contact Dermatitis
- 16% Allergic Contact Dermatitis Of The Thigh
People who have experienced upper leg redness had symptoms persist for:
- 46% Less than a day
- 25% Less than a week
- 12% Over a month
Source: Aggregated and anonymized results from Buoy Assistant.
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