Nummular Eczema: Causes, Symptoms, and Treatments

Nummular eczema is a chronic inflammatory skin condition characterized by round, coin-shaped patches that are itchy, scaly, and prone to blistering or oozing. The Nummular affects the arms, legs, and torso, and is more common in older adults with a history of allergies or dry skin. The condition arises from a combination of skin barrier dysfunction, immune system irregularities, and exposure to environmental triggers (allergens, irritants, and cold or dry climates).

Managing nummular eczema involves identifying and avoiding flare-up triggers, maintaining consistent skin hydration, and using targeted treatments (topical corticosteroids, antihistamines, and barrier-repairing moisturizers). Phototherapy or prescription immunomodulators are recommended. Flare-ups are minimized, and skin health is improved with proper care and lifestyle adjustments.

What is Nummular Eczema?

Nummular Eczema is a chronic skin condition marked by round, coin-shaped patches that are dry, scaly, and inflamed. The term “nummular” comes from the Latin word for “coin,” describing the distinct shape of the lesions. The patches appear on the legs, forearms, hands, or torso and ooze clear fluid or develop a crusty surface. The condition is persistent, with flare-ups recurring in the same areas even after treatment. It is mistaken for ringworm due to its circular appearance, but it is non-infectious and linked to skin barrier dysfunction and environmental triggers.

Common descriptors include circular eczema, coin-shaped dermatitis, skin inflammation, dry skin patches, and chronic skin conditions. The lesions are itchy and visibly raised, contributing to discomfort and potential secondary infections if scratched. Nummular eczema is one of the recognized Type of Eczema, distinguished by its chronic nature. Explore nummular eczema pictures to understand its presentation better and differentiate it from other eczema types.

The Nummular Eczema is shown in the image below. 

Who Can Get Nummular Eczema?

Children and adults can have Nummular Eczema, but it is commonly diagnosed in adult males and patients with a history of atopic dermatitis or allergic skin disorders. Nummular Eczema is classified under chronic skin disorders and is associated with an abnormal immune response that disrupts the skin barrier. Nummular eczema tends to emerge in adults, while eczema in children is linked to atopic dermatitis and affects patients aged 50 and above. Men vs women prevalence varies by age. Adult males develop nummular eczema, while females show higher rates of eczema types. Patients with a prior diagnosis of atopic dermatitis, allergic contact dermatitis, or infected eczema are at increased risk. 

The presence of dry skin, environmental irritants, and seasonal changes triggers flare-ups. Nummular eczema is distinct in its coin-shaped presentation and chronic nature, but eczema in children evolves into other forms later in life. It is considered a type of eczema, separate from other variants (seborrheic or dyshidrotic eczema). Nummular eczema occurs in patients with compromised immunity or patients exposed to harsh climates. Living in low-humidity environments or frequently using hot water and soaps makes nummular more susceptible. Skin trauma, insect bites, or chemical exposure trigger the condition. Early recognition and treatment help prevent progression and reduce discomfort in age groups.

How Does Nummular Eczema Differ from Other Types of Eczema?

Nummular Eczema differs from other types of eczema through coin-shaped lesions, triggers, and chronic presentation. Nummular eczema forms isolated, round plaques that resemble coins, unlike atopic dermatitis, which begins in childhood and presents as widespread itchy patches in skin folds. The eczema causes lesions that are scaly, dry, and inflamed, appearing on the limbs and trunk. Contact dermatitis arises from direct exposure to irritants or allergens and is characterized by localized skin rashes that match the area of contact.

Nummular eczema is linked to environmental dryness, skin trauma, and microbial colonization, while atopic dermatitis involves genetic predisposition and immune dysregulation. Contact dermatitis is purely reactive, triggered by substances (nickel, fragrances, or harsh soaps). Nummular eczema or discoid eczema stands out for its defined circular plaques and tendency to recur in the same areas, in comparison with other eczema types comparison. It shares with Dyshidrotic Eczema, another form marked by vesicles on the hands and feet, but differs in shape and location.

Nummular eczema differs in treatment response, requiring potent topical corticosteroids, emollients, and antibiotics for infected plaques. It resists standard eczema therapies and recurs seasonally. Patients with nummular eczema benefit from skincare routines, barrier repair strategies, and trigger avoidance. Its chronic nature demands long-term management and regular dermatological follow-up to prevent complications.

What are the Common Nummular Dermatitis Symptoms?

The Common Nummular Dermatitis Symptoms are listed below. 

• Itching: Itching is persistent and intensifies at night or in dry environments. It disrupts sleep and daily comfort, leading to compulsive scratching. Repeated scratching worsens inflammation and increases the risk of skin damage.

• Round Eczema Patches: The condition presents as sharply defined, coin-shaped plaques. The patches are dry, scaly, and inflamed, appearing on the limbs or trunk. The circular shape differentiates nummular eczema from other eczema types.

• Blistering: The lesions develop small blisters filled with clear fluid. Blistering indicates acute inflammation and precedes crust formation. Ruptured blisters expose raw skin and heighten infection risk.

• Scaling: Affected areas show visible flaking and dryness due to impaired skin barrier function. Scaling reflects chronic inflammation and epidermal turnover. It contributes to the rough texture of the lesions.

• Inflamed Skin: Inflammation manifests as redness, swelling, and warmth around the lesions. It results from immune system overactivity and external irritants. Inflamed skin feels tender or painful to touch.

• Skin Lesions: Lesions vary from dry plaques to moist, crusted eruptions depending on severity. Chronic scratching causes thickening or lichenification. Lesions are prone to recurrence in the same anatomical sites.

• Redness: Erythema surrounds the plaques, signaling active inflammation. The redness deepens with scratching or exposure to allergens. It is a visible marker of immune response in the skin.

• Eczema Flare-Ups: Symptoms worsen due to environmental or internal triggers. Flare-ups last for weeks and recur in previously affected areas. Management requires consistent skin care and trigger avoidance.

• Bleeding: Excessive scratching or ruptured blisters lead to minor bleeding. Open wounds compromise the skin barrier and invite microbial invasion. Bleeding lesions require prompt care to prevent complications.

• Secondary Infection: Infected plaques ooze, crust, or emit odor, indicating bacterial colonization. Staphylococcus aureus is commonly involved in eczema-related infections. Antibiotic treatment is required for resolution.

Who is Most at Risk for Developing Nummular Eczema?

The patients who are at risk of developing Nummular Eczema are listed below. 

• Older Adults (Age 50 and Above): Adults over 50 are more prone to nummular eczema due to age-related skin thinning and reduced moisture retention. Dry skin becomes more common with aging, increasing susceptibility to coin-shaped lesions. Cold climates and indoor heating aggravate skin dryness.

• Adult Males: Men are more affected than women in middle and late adulthood. Occupational exposure to irritants and reduced skincare routines contribute to flare-ups. Environmental factors (harsh soaps or chemicals) are common triggers.

• Patients with a History of Allergies: Patients diagnosed with allergic rhinitis, asthma, or food allergies are at higher risk. Allergic reactions compromise the skin barrier and provoke immune system responses. It reflects broader sensitivity to environmental triggers.

• Atopic Dermatitis or Eczema History: A personal or family history of atopic dermatitis increases the risk of developing nummular eczema. Genetic predisposition affects immune regulation and skin barrier integrity. Flare-ups resemble other eczema types but are distinct in shape.

• Living in Cold or Dry Climates: Regions with low humidity and cold temperatures contribute to chronic skin dryness. Seasonal changes (winter) lead to increased flare-ups. Indoor heating systems dehydrate the skin.

• Chronic Dry Skin (Xerosis): Persistent dry skin weakens the epidermal barrier, making it vulnerable to inflammation. Lack of moisture allows irritants to penetrate more easily. The condition is common in older adults and patients with poor hydration habits.

• Exposed to Harsh Chemicals or Irritants: Workers in cleaning, construction, or healthcare frequently contact soaps, solvents, and disinfectants. The substances strip natural oils and trigger skin inflammation. Repeated exposure increases the risk of lesion development.

• Immune System Dysregulation: Abnormal immune responses play a role in nummular eczema. The body overreacts to minor irritants, leading to chronic inflammation. The mechanism overlaps with other inflammatory skin disorders.

• Skin Injuries or Frequent Abrasions: Minor trauma (scratches, insect bites, or friction) initiates lesions. Damaged skin is more susceptible to microbial colonization and flare-ups. Healing is slower, especially in dry or aged skin.

• Under High Emotional Stress: Stress influences immune function and skin health, contributing to flare frequency. Psychological strain worsens existing lesions or triggers new ones. Stress management is essential in long-term eczema care.

The immune system dysfunction in nummular eczema causes exaggerated reactions to minor triggers, resulting in chronic inflammation. Eczema triggers vary by patients but include physical trauma, microbial colonization, and emotional strain. The causes distinguish nummular eczema from other chronic skin conditions. Genetic predisposition plays a role in patients with a family history of atopic diseases. Skin injuries (insect bites, abrasions, or burns) initiate lesion formation. Medications, including interferon or isotretinoin, worsen symptoms. Hormonal changes and aging affect skin resilience, making older adults more susceptible. Identifying and minimizing the triggers is essential for long-term management.

How is Nummular Eczema Diagnosed?

Nummular eczema is diagnosed through visual skin examination, patch testing for allergens, and biopsy procedures to exclude other skin conditions. Dermatologists begin by assessing the shape, distribution, and texture of the lesions (round, scaly, and inflamed plaques) on the limbs or trunk. The clinical evaluation helps differentiate nummular eczema from similar conditions (ringworm, psoriasis, or contact dermatitis).

Patch tests are performed to identify allergic triggers in cases where the diagnosis is unclear or symptoms are resistant to treatment. Patients with nummular eczema react positively to contact allergens, indicating a link between environmental exposure and flare-ups. A skin biopsy is conducted to rule out other chronic skin disorders (cutaneous T-cell lymphoma or fixed drug eruptions).

The diagnostic process relies on recognizing hallmark features, coin-shaped lesions, chronic recurrence, and absence of fungal infection. Dermatologists use magnification tools and review patient history, including prior eczema types and immune-related conditions. Accurate diagnosis ensures appropriate treatment for nummular eczema.

What Treatment Options Are Available for Nummular Eczema?

Can you Prevent Flare-Ups of Nummular Eczema?

Yes, you can prevent flare-ups of nummular eczema by maintaining consistent skin hydration, avoiding known triggers, and protecting the skin from environmental stressors. Daily use of fragrance-free moisturizers containing ceramides or colloidal oatmeal helps reinforce the skin barrier and reduce sensitivity. Avoiding irritants (harsh soaps, synthetic fabrics, and chemical exposure) is essential in cold or dry climates where flare-ups are more frequent.

Stress management plays a role, as emotional strain disrupts immune regulation and worsens symptoms. Wearing breathable, protective clothing and using hypoallergenic skin-care products minimizes contact with allergens and irritants. Gentle cleansing routines, lukewarm baths, and post-shower moisturization help preserve skin integrity. Tracking flare-up patterns, using wet wrap therapy in acute episodes, and consulting a dermatologist for tailored treatment plans reduce recurrence and severity.

Does Weather Affect Nummular Eczema?

Yes, weather affects nummular eczema. Cold, dry winters deplete skin moisture, weakening the epidermal barrier and triggering coin-shaped lesions. Low humidity intensifies dryness, making the skin more reactive to irritants. Hot and humid summers increase sweat and oil production, which clog pores and aggravate inflammation. Sudden temperature shifts and indoor heating disrupt skin balance in patients with preexisting eczema.

Apply moisturizers immediately after bathing to retain hydration and protect the skin in varying climates. Use a humidifier during dry seasons to maintain indoor moisture. Avoid prolonged hot showers that strip natural oils. Wear breathable fabrics and cleanse gently to remove sweat in warm weather. Apply fragrance-free emollients and barrier creams regularly, and shield exposed skin from harsh winds or direct sunlight.

When should you see a Doctor About Nummular Eczema?

You should see a doctor about Nummular Eczema when symptoms worsen, do not improve with over-the-counter treatments, or show signs of secondary infection (pus, increased pain, or fever). Persistent itching, expanding lesions, or bleeding from cracked skin indicate that the condition is beyond self-care. Medical evaluation is essential when flare-ups interfere with sleep, work, or daily activities, or when the diagnosis is uncertain.

Professional help ensures accurate identification of triggers and access to prescription-strength treatments like topical corticosteroids, immunomodulators, or antibiotics for infected lesions. Dermatologists perform patch testing to rule out contact allergies or recommend phototherapy for chronic cases. Early intervention prevents complications such as scarring, skin thickening, or emotional distress. Timely care improves long-term outcomes and helps adapt a management plan suited to the patient’s skin type and lifestyle.

Is Eczema Bacterial?

No, Eczema is not bacterial. Eczema is a non-infectious inflammatory skin condition caused by immune system dysfunction, genetic predisposition, and environmental triggers, not by bacteria. It does not originate from bacterial infections or involve transmissible pathogens. Eczema becomes complicated by secondary bacterial infections when the skin barrier is broken due to scratching or severe dryness.

Staphylococcus aureus is the most common bacterium found on infected eczema lesions. The presence worsens inflammation, delays healing, and increases the risk of infected eczema. Signs of bacterial involvement include oozing, crusting, increased redness, warmth, and pain. Patients require topical or oral antibiotics, antiseptic washes, and strict hygiene practices to manage the complications. Preventing bacterial eczema triggers involves moisturizing regularly, avoiding skin trauma, and treating flare-ups promptly to maintain barrier integrity.

Disclaimer: This content is for informational purposes only and is not intended as medical advice. Always consult with a healthcare professional before starting any new skincare routine or supplement. These statements have not been evaluated by the Food and Drug Administration.