Nummular dermatitis

Editor-In-Chief: Prab R Tumpati, MD
Obesity, Sleep & Internal medicine
Founder, WikiMD Wellnesspedia &
W8MD medical weight loss NYC and sleep center NYC

Nummular dermatitis
Synonyms	Discoid eczema, nummular eczema
Pronounce	N/A
Specialty	Dermatology
Symptoms	Itchy and coin-shaped rash
Complications	N/A
Onset	Any age, more common in adults
Duration	Chronic, with periods of remission and exacerbation
Types	N/A
Causes	Unknown, possibly related to dry skin, allergies, or environmental factors
Risks	Atopic dermatitis, asthma, allergic rhinitis
Diagnosis	Clinical examination, skin biopsy
Differential diagnosis	Tinea corporis, psoriasis, contact dermatitis
Prevention	N/A
Treatment	Moisturizers, topical corticosteroids, antihistamines
Medication	N/A
Prognosis	N/A
Frequency	Relatively uncommon
Deaths	N/A

Nummular dermatitis, also known as nummular eczema, is a chronic inflammatory skin condition characterized by coin-shaped, itchy, and scaly patches. The term "nummular" is derived from the Latin word "nummus," meaning "coin," which describes the round appearance of the lesions.

Clinical Presentation

Nummular dermatitis typically presents as well-defined, round to oval erythematous plaques that are often pruritic. These lesions can appear anywhere on the body but are most commonly found on the arms, legs, and torso. The plaques may become crusted, weepy, or lichenified over time due to chronic scratching and irritation.

Pathophysiology

The exact cause of nummular dermatitis is not well understood, but it is believed to be a multifactorial condition involving genetic, environmental, and immunological factors. It is often associated with xerosis (dry skin) and may be exacerbated by environmental triggers such as cold weather, low humidity, and irritants like soaps and detergents.

Diagnosis

Diagnosis of nummular dermatitis is primarily clinical, based on the characteristic appearance of the lesions. A thorough history and physical examination are essential to differentiate it from other forms of eczema and dermatitis. In some cases, a skin biopsy may be performed to rule out other conditions such as psoriasis or tinea corporis.

Management

Management of nummular dermatitis involves a combination of lifestyle modifications, topical treatments, and, in some cases, systemic therapies. Key strategies include:

• Moisturization: Regular use of emollients to maintain skin hydration and barrier function.
• Topical Corticosteroids: Application of topical steroids to reduce inflammation and pruritus.
• Avoidance of Triggers: Identifying and avoiding potential irritants and allergens.
• Systemic Treatments: In severe cases, systemic corticosteroids or immunosuppressants may be considered.

Prognosis

Nummular dermatitis is a chronic condition with a tendency to recur. While it can be managed effectively with appropriate treatment, some individuals may experience persistent or recurrent episodes. Long-term management focuses on minimizing flare-ups and maintaining skin health.

See Also

• Eczema
• Atopic dermatitis
• Contact dermatitis
• Psoriasis