Nummular Dermatitis
Pronunciation: NUM-yoo-lar der-mah-TY-tis
A chronic eczematous condition characterised by coin-shaped (discoid) plaques of inflamed, itchy skin, most commonly on the limbs.
Full Definition
Nummular dermatitis, also called discoid eczema, is a form of chronic eczematous dermatitis presenting as discrete, coin-shaped patches that are erythematous, vesicular, and intensely pruritic. The lesions most frequently appear on the lower legs, trunk, and dorsal hands in middle-aged to older adults. The aetiology is multifactorial, involving dry skin, atopy, and environmental triggers. Editors must note that 'nummular' (from the Latin 'nummus,' meaning coin) is the preferred adjective in North American medical writing, while 'discoid eczema' prevails in UK usage; consistency within a document is essential. It should not be confused with tinea corporis, which produces annular lesions with central clearing.
Usage
Usage note: Flag 'discoid eczema' vs. 'nummular dermatitis' as a regional variant in style notes; do not treat as an error without consulting the house style guide.
In Context
- "The dermatology report referred to 'discoid eczema,' but house style required the term to be changed to 'nummular dermatitis' throughout." — Copy-editing note
- "Nummular dermatitis lesions were distributed symmetrically across the extensor surfaces of both forearms." — Clinical case report