A skin rash on one lower leg can appear red, blotchy, or have a dry and scaly texture. Most rashes on the lower leg are caused by dermatitis, eczema, or an allergic reaction which will look like red, itchy bumps on the leg. Read below for more information on lower leg rashes and treatment options.
6 most common cause(s)
Rashes on the lower legs explained
Rashes are dermatologic conditions that can affect the color, texture, and even sensation of the skin. They can develop on the skin anywhere on the body, and rashes on the lower extremities are common and can range from benign to serious.
Common characteristics of rash on one lower leg are
The following characteristics will likely be present if you are experiencing this symptom.
- Pain/burning
- Pruritus (itching)
- Swelling
- Dryness
- Changes in skin texture (scaly, leathery, papery)
- Blisters or bumps
- Petechiae (pinpoint round spots)
Common accompanying symptoms are
Scratching is also an important symptom of a rash on the lower leg. Though scratching can be helpful in relieving any itchy sensation that may be occurring, it only offers temporary relief. Scratching can also result in breaks in the skin that can lead to bleeding or infection, further exacerbating the issue. Along with scratching, symptoms may include:
- Fever
- Joint pain
- Weight loss
- Fatigue
- Bruising
Rashes on the lower legs can be a signal of conditions that range from benign to life-threatening. It is important to make an appointment with your doctor in order to get the proper diagnosis, receive appropriate care and prevent complications.
What causes a rash on the calves, shins, or ankles?
The causes of rash on the leg are varied and range from benign to life-threatening. This can seem daunting because it may be difficult to classify the severity of your rash and any associated symptoms.
Dermatologic
The majority of rashes on the legs are dermatologic in nature. Many skin conditions such as eczema, hives, psoriasis and a variety of other illnesses that specifically affect the skin and its layers can result in a rash of the lower extremities. Often, such conditions are also associated with symptoms such as redness, blisters or flaking. On the other hand, skin that is simply dry or that seems rashy may be due to the skin naturally being more dry with old age or temperature changes.
Inflammatory
Most causes of rash are inflammatory in nature.
- Infectious: The skin is home to a bacterium known as Staphylococcus aureus. Although it is a normal component of the skin flora, it is the leading cause of human bacterial infection and can result in redness and irritation superficially on the body. This type of skin infection is called cellulitis. Staphylococcus aureus can enter the skin via small lesions or cuts and result in painful, red, swollen areas on the skin. Other types of bacteria, fungi, and viruses can also cause such infections; however, Staphylococcus aureus is the most common.
- Autoimmune: Many inflammatory diseases that result in the body attacking itself can result in chronic inflammation that commonly manifests as a rash on different parts of the body, including the lower extremities.
Systemic
Rashes in the lower legs may be a sign of an underlying, systemic condition. There are many illnesses that can also cause itching and they can be grouped into the following categories:
- Metabolic: Conditions such as diabetes and thyroid disease that affect the metabolic homeostasis of the body can result in rashes of the lower leg as well as other parts of the body.
- Hematologic: Blood conditions such as anemia and leukemia can cause specific rashes on the lower legs and be associated with symptoms such as fatigue and weight loss.
- Neurologic: Conditions that affect the nervous system such as shingles and diabetes can also result in rashes or itching of the lower extremities and other parts of the body.
Environmental
There are many environmental causes for rashes on the lower extremities and other body parts.
- Allergens: The skin works primarily as a protective barrier and is very sensitive to environmental factors that cause irritation or allergic reactions. Allergens can include drugs, topical treatments such as soaps or lotions, certain fabrics or metals, plants, foods and a variety of other substances. Itching acts as a warning or deterrent from using these irritants.
- Drug reactions: Many drugs can cause serious skin reactions that manifest as a rash on the lower legs. There are some drugs where rashes are a known side effect, but it is not always possible to predict how your body will react. If you believe you are having a rash from a medication, seek medical attention. Some drug reactions are potentially life-threatening.
This list does not constitute medical advice and may not accurately represent what you have.
Non-specific dermatitis (skin inflammation)
Nonspecific dermatitis, or contact dermatitis, simply means inflammation of the skin from many different causes.
Most nonspecific dermatitis is caused by skin contact with a substance that provokes a reaction, which could be anything from plants to soap to jewelry to fabrics. Some may be due to an autoimmune condition, where the body's immune system attacks itself.
Risk factors include a family or personal history of allergies, asthma, or other condition which weakens the immune system; or constant contact with metals, plant life, or chemicals.
Symptoms commonly include red, swollen skin rash with itching, blistering, or oozing, which may become painful and infected.
Dermatitis itself is not contagious but can interfere with quality of life. A medical provider can help with managing the symptoms.
Diagnosis is made through patient history, physical examination, and sometimes skin biopsy and patch testing.
Treatment involves using protective measures if the substances cannot be avoided; making nutritional improvements to strengthen the immune system; using corticosteroid or other creams; and phototherapy.
Rarity: Common
Top Symptoms: red rash, itchy rash, painful rash
Symptoms that always occur with non-specific dermatitis (skin inflammation): red rash
Urgency: Self-treatment
Chronic hepatitis c
Chronic hepatitis C is a liver inflammation caused by Hepacivirus C.
If someone is infected with hepatitis C and gets the acute form of the disease, there is about a 50% chance of the disease becoming chronic. This means that the virus remains in the body after the acute, short-term disease is over, and may or may not cause further illness.
Some patients have no symptoms of chronic hepatitis C until years later, when liver damage has developed and the signs of cirrhosis (scarring) begin to appear. Hepatitis C can also lead to liver cancer.
Diagnosis is made through blood tests.
Treatment for chronic hepatitis C involves taking medications prescribed by the physician; avoiding alcohol; and using no supplements or prescription medications without a doctor's clearance. In some cases, a liver transplant will be needed to save the patient's life.
The best prevention is to never share needles, toothbrushes, or other personal care items, and to always practice safe sex. There is no vaccine for hepatitis C.
Rarity: Common
Top Symptoms: fatigue, nausea, muscle aches, loss of appetite, joint pain
Symptoms that never occur with chronic hepatitis c: pain in the lower right abdomen, pain in the lower left abdomen, pain in the upper left abdomen, pain around the belly button
Urgency: Primary care doctor
Allergic contact dermatitis of the lower leg
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, fragrance, and cosmetics.
Rarity: Common
Top Symptoms: lower leg redness, lower leg itch, scabbed area of the lower leg
Symptoms that always occur with allergic contact dermatitis of the lower leg: lower leg redness
Urgency: Self-treatment
Seborrheic dermatitis
Seborrheic dermatitis is a common chronic inflammatory skin condition that causes flaky, white to yellowish scales to form on oily areas such as the scalp, face or inside the ear. It can occur with or without reddened skin. The exact cause of this condition is not known, although doctors think that some common skin yeast organisms, called Malassezia, may play a role in some people.
You should go to a retail clinic to be treated. There are a variety of medicated creams that are used for this condition such as prescription or over-the-counter shampoos containing zinc pyrithione, hydrocortisone, selenium sulfide, or salicylic acid.
Rarity: Common
Top Symptoms: itchy rash, red or pink, rough patch of skin, rash with well-defined border, scalp skin changes, cheek skin changes
Symptoms that never occur with seborrheic dermatitis: fever
Urgency: Phone call or in-person visit
Pityriasis rosea
Pityriasis rosea is a common skin rash and is thought to be due to a type of herpes virus. It is not contagious and is not sexually transmitted. Most susceptible are teenagers and young adults.
Symptoms include a single large scaly patch somewhere on the body. In the next 7 to 14 days similar oval pink patches on the arms, legs, and trunk appear, sometimes in a pattern of lines.
There may also be itching, fatigue, and body aches along with the rash. Anything that raises body temperature, such as exercising or a hot bath, may worsen the rash.
The condition may last for a few weeks and is normally gone after three to four months. Sometimes flat brown spots are left as the rash fades.
Pityriasis rosea can resemble other conditions, so getting an accurate diagnosis is important. Diagnosis is made through blood tests and skin cultures.
Treatment involves topical medications for itching, as well as antiviral and anti-inflammatory medications by mouth to aid healing. Cool baths and reduced exercise will also help.
Rarity: Rare
Top Symptoms: rash, itchy rash, curved rash, rough patch with red spots around it
Symptoms that always occur with pityriasis rosea: rash
Symptoms that never occur with pityriasis rosea: blue-colored skin changes, black-colored skin changes, brown-colored skin changes
Urgency: Self-treatment
Non-specific skin rash
Nonspecific skin rash means any sort of unexplained outbreak on the skin.
Common causes of rash are contact dermatitis, sun damage, or allergic reaction. However, many rashes are a symptom of disease and should not be ignored.
Nonspecific rashes have widely varied symptoms:
- May be flat and smooth; slightly raised or with swollen welts; clean and dry; or blistered and oozing.
- May spread widely over the body, or be confined to one site.
- May appear after eating certain foods; or after exposure to certain plants or to insect stings or bites.
- Other symptoms may be present, including pain anywhere in the body; nausea; vomiting; fever; headache; or abdominal pain and upset.
Diagnosis is made through patient history and physical examination to determine the exact type, location, and history of the rash, along with any other symptoms that may be present.
Those symptoms will be investigated with blood tests or imaging. Skin swabs may be taken and tested. After the process has ruled out as many causes as possible, a course of treatment can be determined.
Rarity: Common
Top Symptoms: rash
Symptoms that always occur with non-specific skin rash: rash
Urgency: Wait and watch
Lower leg weakness
Any leg weakness is a sign of nerve damage, which is very worrisome and requires you to go see a doctor immediately!
Rarity: Uncommon
Top Symptoms: lower leg weakness, foot weakness, arm weakness, loss of vision, severe pelvis pain
Urgency: Hospital emergency room
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
Hives
Hives, or urticaria, are flat red welts that can appear anywhere on the skin and usually itch. The cause is an allergy, either to something eaten or to something that has touched the skin. Foods, medicines, certain plants, or even sunlight are common causes, as are stress, infections, and autoimmune illness.
Symptoms include an itchy, stinging rash of slightly swollen skin welts that may come and go continuously, so that there are always some hives visible. Acute will disappear within six weeks, but chronic last longer.
Persistent hives should be seen by a medical provider, both to ease the symptoms and to make sure the allergy is not a serious one.
Diagnosis is made through patient history, physical examination, blood tests, and sometimes allergy tests.
Hives often resolve on their own, especially in children since they may outgrow their allergies. Otherwise, treatment for acute hives involves an antihistamine medication taken by mouth to help relieve the itching and stinging. Chronic hives may additionally be treated with corticosteroids, antibiotics, and other stronger medicines.
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 flareups.
How to relieve a rash on the lower legs
At-home treatment
Many causes of rash on the lower leg and its associated symptoms can be stopped or prevented with simple lifestyle changes:
- Keep the skin adequately moisturized: Using unscented, dermatologically tested lotions and moisturizing cream on the lower leg can prevent skin dryness that can cause a rash.
- Avoid allergens: Take note of symptoms that occur after using or ingesting certain substances and try to avoid them. It may be helpful to get formal allergy testing in order to be prepared and knowledgeable about your allergic triggers.
Here’s some advice on managing this at home and when you might need to consult your doctor.
Hydrocortisone Cream: This can help alleviate itching and reduce inflammation.
Moisturizing Lotions: Keeping the area moisturized can prevent dryness and ease irritation.
Antihistamines: If the rash is itchy and you suspect an allergy, OTC antihistamines can provide relief.
When to see a doctor
If your lower leg rash persists despite the home remedies above, make an appointment with your doctor. If your itching is caused by an underlying metabolic, hematologic or neurologic condition, your doctor will focus on treating that condition first. If your symptoms are due to another cause, he or she may suggest the following treatments that may help relieve your itchy skin:
- Corticosteroid creams: If your itching is due to a rash or skin disorder such as eczema or dermatitis, corticosteroids are helpful given their anti-inflammatory effect in addition to their immunosuppressive role.
- Antihistamines: If your itching is due to an allergic reaction, your doctor may prescribe medications that fight the immunologic response causing your inflammation and itching.
- Light therapy (phototherapy): This treatment involves exposing the skin to specific wavelengths of ultraviolet light in order to help get the itching sensation under control.
When it is an emergency
Most causes of rashes on the lower extremity are benign. However, be very concerned if you notice the following symptoms in addition to your rash:
- Changes in color of the skin (more than redness or irritation)
- Pus or oozing from the affected area
- High fever
- Altered mental status
- Nausea/vomiting
- Neck pain
- Lethargy
These may be signs of serious life-threatening conditions such as meningitis or necrotizing fasciitis that require immediate attention.
FAQs about rash on one lower leg
Why is the rash only on one of my lower legs?
The lower extremities are particularly sensitive to changes in temperature and become easily dry and itchy, especially in low humidity conditions. The skin overlying the shin is the thinnest and often the first to be affected in many dermatologic conditions, especially skin dryness. One leg may simply be drying out more than the other if it is not adequately protected or moisturized. It is important to see your physician if the rash worsens or persists.
Will the rash spread from my lower leg to the rest of my body?
Depending on the specific cause of your lower leg rash, there is a possibility that the rash and irritation can spread from the lower leg to the rest of the body. For example, in many systemic diseases, itching may result in multiple extremities while in the case of an insect bite, the rash will not likely spread.
What are the complications of lower leg rash?
Complications of lower leg rash are usually the result of constant itchiness and persistent scratching. Scratching can cause breaks in the skin that lead to infection or other skin injury. Furthermore, scratching can lead to scarring and thickening of the skin.
Is lower leg rash a temporary or chronic condition?
Lower leg rash can be either temporary or chronic depending on the underlying cause. Usually, lower leg rash associated with allergens resolves after discontinuing the offending agent. However, lower leg rash associated with chronic conditions such as diabetes or liver disease can persist especially if adequate treatment is not obtained.
What are petechiae/what is a petechial rash?
Petechiae are small pinpoint spots that coalesce into a rash and do not disappear after applying pressure to the area (non-blanching). They happen and appear because of bleeding into the skin from broken capillaries. They can be caused by a variety of conditions (infectious, traumatic, systemic) and usually signal a more serious problem that requires medical follow-up.
Questions your doctor may ask about rash on one lower leg
- Any fever today or during the last week?
- What color is the skin change?
- Are there bumps on your rash?
- Does the rash have a clearly defined border?
Self-diagnose with our free Buoy Assistant if you answer yes on any of these questions.
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References
- McGrath A, Barrett MJ. Petechiae. [Updated 2018 Oct 27]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2018 Jan-. NCBI Link
- What’s the difference between eczema and psoriasis? American Academy of Dermatology. AAD Link
- Aly R. Microbial Infections of Skin and Nails. In: Baron S, editor. Medical Microbiology. 4th edition. Galveston (TX): University of Texas Medical Branch at Galveston; 1996. Chapter 98. NCBI Link
- Signs and Symptoms of Acute Myeloid Leukemia (AML). American Cancer Society. Updated Aug. 21, 2018. American Cancer Society Link
- Necrotizing Fasciitis: All You Need to Know. Centers for Disease Control and Prevention. Updated Oct. 18, 2018. CDC Link
- Hersi K, Kondamudi NP. Meningitis. [Updated 2018 Oct 27]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2018 Jan-. NCBI Link