Nummular Dermatitis: Causes, Signs, and Treatment

Many people are aware of what dermatitis and eczema are. However, more often than not, they do not know the specific kind they have. How is nummular dermatitis different from the rest? Read on to know more about it.

What Is Nummular Dermatitis?

Nummular dermatitis is a common chronic skin condition that forms stubborn, itchy rashes in circular patches on skin. The term nummular is a Latin word pertaining to a coin. Hence, the distinct appearance. 

It can appear as a single lesion or in multiple locations throughout the body. Over time, plaques have the tendency to clear out in the center or become scaly. Thus, making the impression of resembling ring worm or psoriasis. When left untreated, it can last for weeks, months, or even years. Or, in some instances, it may reoccur at the same place where it first appeared. 

Some people also refer to this as nummular eczema, discoid eczema, or dermatitis. 

Any person at any age can develop nummular dermatitis. However, it is more likely to develop in people with:

• Atopic eczema
• Eczema as a child
• Infected eczema
• Allergic contact dermatitis

Although some studies suggest that discoid eczema is not a hereditary disease.

It may appear on the legs as a result of poor blood flow in the lower body and stasis dermatitis caused by these circulation issues.

Signs and Symptoms of Nummular Dermatitis

Signs and symptoms of nummular dermatitis may be quite similar as with other types of dermatitis or eczema such as:

• Group of small bumps or spots on the skin (or lesions in the space of a coin on the arms, legs, and/or hands)
• Burning and itching sensation
• Dry skin
• Swollen, blistered and ooze-filled patches
• Pink, red, or brown scaly and inflamed sores (patches will appear pink or red on lighter skin while it can be dark brown or paler in color on darker skin)

When the patches gets infected, some symptoms may include:

• Fluid-filled patches
• Formation of yellow crust over the patches
• Skin surrounding the patches tends to become hot, swollen, and painful
• Sick/ unwell feeling
• Warm or shivery feeling

This type of dermatitis is more distinguishable in comparison to others due to its oval or coin appearance. Your dermatologist will be able to diagnose it just by looking at the spots on your skin. There are cases wherein your dermatologist may need a skin biopsy or your family medical history. 

Causes of Nummular Dermatitis

Despite being a common skin condition. Its causes are still unknown. However, the most common feature of this condition is dry skin. 

When your skin is extremely dry, it is unable to form a strong barrier against compounds that interact with it. This could cause an otherwise harmless substance, such as soap, to inflame the skin.

This is why it is necessary to thoroughly examine the chemicals present in your cosmetics and toiletries. Contact dermatitis can play a role and cause the development of nummular dermatitis.

Other triggers worth mentioning are:

• Personal/family medical history (allergies, asthma)
• Intake of medications (statins, interferons, or ribavirin)
• Environmental irritants
• Temperature changes (most especially in colder months)
• Stress

Treatment

Although nummular dermatitis is a long-term condition, there are many medications and treatments available to address it. 

This type of dermatitis frequently occurs as a result of minor skin injuries. Thus, it is of importance to take care of the skin from such incidence. You may also want to avoid allergens and irritants that come in contact with skin. 

Emollients such as soap substitutes, bath oils, and moisturizing creams can help in relieving itching, scaling, and dryness. Thus, doctors recommend frequent use of it. 

Other anti-inflammatory treatments include:

• Topical steroids and corticosteroids for swelling, redness, and itchiness 
• Antibiotics for discoid eczema showing signs of infection

Those who are diagnosed with the severe kind may need prescribed treatments from the doctor such as:

• Oral antihistamines
• Ultraviolet radiation (UV) treatment
• Steroid injections
• Oral treatments

Learn more about Dermatitis here.