Common causes of lower leg rashes include diabetes, varicose eczema, and allergic reactions. Since some leg rashes signal an underlying health condition, consulting a dermatologist is recommended.
Most skin conditions can cause rashes on the lower legs, from psoriasis to eczema. For that reason, if you’re experiencing redness, itchiness, or any other rash symptoms, there are dozens of possible explanations, so it’s a good idea to consult a professional for a thorough diagnosis.
That being said, some conditions, including those linked to circulation issues or allergic reactions, are likelier than others to cause a rash. Here’s what to know.
Common Causes of Lower Leg Rashes
Circulation Issues: Poor Blood Flow and Varicose Veins
A lower leg rash may be caused by a condition called stasis dermatitis, which shows up as itchy, dry, sore or discolored skin; a heavy or achy feeling in one or both legs; swelling in the leg that stops during sleep and/or appears on the inside of the ankle.
Stasis dermatitis, also known as venous eczema, varicose eczema, or gravitational dermatitis, is a common condition. In the U.S., an estimated 15 to 20 million people over 50 experience this form of eczema.
With age, the valves in the lower extremities may weaken. When functioning as they should, these valves send blood upwards to the heart. When they’re worn down, some degree of fluid may leak and pool in the legs.
The pooled liquid then causes swelling, or a condition called venous insufficiency. This condition may also make veins bulge, itch and even hurt, also known as varicose veins. Those with a higher risk of venous insufficiency include older individuals and people with a leg injury, blood clot(s) in the leg or who’ve recently undergone surgery.
Allergic Reactions and Contact Dermatitis
A lower leg rash may also occur due to an allergic reaction or contact dermatitis, a form of eczema that occurs when your skin comes in direct contact with an irritating substance. The rash is typically itchy, red, and inflamed.
Substances that may trigger this reaction include lotions, soaps, certain fabrics like wool, and plants like poison ivy. Shaving may also cause a rash. The rash may show up within minutes to hours of exposure.
Once you avoid the triggering substance, the rash should clear in about two to four weeks. In the meantime, you can soothe your legs using a cool washcloth and a hypoallergenic cleanser and lotion.
Other Health Conditions Linked to Lower Leg Rashes
Sometimes, rashes on the lower legs signal another underlying condition, including:
- A blood clot (deep vein thrombosis) may cause redness, heat, and inflammation in the affected leg, typically in the calf or thigh. Since blood clots can cause serious, potentially life-threatening complications, you should seek immediate emergency medical attention if you suspect a blood clot.
- Diabetes. Skin issues, especially of the lower extremities, are very common in those with diabetes. Diabetes is characterized by reduced blood flow and high blood sugar, which can lead to damage to the skin’s small blood vessels and the development of lesions. One such complication of diabetes is called diabetic dermopathy, commonly called shin spots, which manifests as light brown or red, scaly patches on the lower legs.
Recognizing the Symptoms of a Lower Leg Rash
Skin Discoloration: From Brown to Purple
The signs of a rash on your lower leg can vary widely depending on the cause. For instance, if you notice any of the following, your condition may be related to blood flow issues or varicose veins:
- Swelling of the legs and/or feet
- Brownish, bluish or purplish discoloration, especially surrounding veins
- Calves that feel tender or hot to the touch
- A feeling of leg heaviness that worsens as the day goes on
Other Warning Signs: Open Sores, Scaly Patches, and More
Meanwhile, symptoms that may indicate contact dermatitis or an allergic reaction include:
- Skin that burns, stings, or itches
- Tender skin
- A rash, tiny red bumps, hives or patches of discoloration
- Blisters or lesions that may contain pus, ooze, or crust over
- Scaly, dry patches of skin that show up shortly after exposure to an irritating substance
Finally, the following symptoms may signal an underlying health condition:
- Open sores that don’t heal (this could indicate a condition like venous ulcers or diabetic ulcers)
- Dark, persistent patches (also possibly linked to diabetes)
- Sudden redness or swelling in just one leg (possibly indicating a blood clot or cellulitis, a bacterial infection)
What Happens if Lower Leg Rashes Are Left Untreated?
Long-Term Risks and Complications
If untreated, leg rashes may progress to a more serious condition, including:
- Chronic inflammation that impairs blood flow
- Permanent skin discoloration
- Open wounds that fail to heal
- Thickened or leathery skin in the affected region
In more serious cases, such as a rash due to cellulitis, the untreated bacterial infection may spread to the lymph nodes and become life-threatening.
For that reason, consulting a dermatologist — especially if your rash worsens, is painful, or persists for longer than a few weeks — is highly recommended.
Treatment Options for Lower Leg Rashes
At-Home Remedies: When and How to Try Them
Mild rashes may be soothed by applying a cool compress to itchy and inflamed areas or slathering on a thick, moisturizing emollient to scaly areas. In addition, milder rashes associated with venous issues may be soothed by elevating the legs to reduce pain and swelling and wear compression stockings as recommended by your healthcare provider.
Any contact dermatitis or allergy-related rashes can also be treated by avoiding further contact with the irritant, if known. You can also try over-the-counter hydrocortisone cream (1%) to reduce inflammation or an antihistamine cream to ease itching.
Medical Interventions for Persistent Rashes
If your rash worsens, is accompanied by a fever, spreads rapidly, is painful, and/or persists for longer than a few weeks, consulting a medical professional is advisable. Your doctor may recommend:
- Prescription-strength topical medications such as stronger corticosteroids, topical antibiotics in case of an infection, or prescription antihistamines (for more severe allergic reactions). If you’re diagnosed with eczema or psoriasis, your doctor can also recommend a topical cream specifically for your condition.
- Prescription-strength oral medications, including anticoagulants for blood clots, medications to improve blood flow, anti-inflammatory medications, or oral antibiotics in the case of infection
Treating contact dermatitis typically requires identifying the cause of the rash.
Preventing Rashes on the Legs and Feet
Lifestyle Changes to Support Healthy Skin and Circulation
For venous-related rashes, you can prevent future issues by staying active. For instance, take regular breaks from sitting to walk, which promotes blood flow. Maintaining a healthy weight and elevating your legs when resting will also help. Treating and managing underlying conditions like diabetes will also address issues.
Skincare Tips for Sensitive Areas
Avoiding the irritant that’s causing a contact dermatitis rash is clearly your best bet. So is stopping scratching (tough to do when a rash is very itchy!), as it can lead to an infection.
Moisturizing daily (especially after bathing) with a hydrating, hypoallergenic emollient is recommended, as is avoiding hot showers.
Working with a Piction Dermatologist
Since some leg rashes may worsen or signal a more serious condition, it’s always a good idea to consult a professional for diagnosis and treatment.
When in doubt about your skin condition, the experts from Piction Health can offer the prompt, professional assessment you need.
