Nummulær

Nummulær is a medical term used in Danish (and also found in Norwegian and Swedish medical literature) to describe a lesion or morphology that is coin-shaped: circular or oval plaques with a relatively well-defined border. The size can vary from a few millimeters to several centimeters, and the lesion surface may be erythematous, scaly, crusted, or in some cases relatively flat.

In dermatology, the term is most commonly encountered in relation to nummulært eksem, or nummular eczema, a chronic dermatitis characterized by discrete, round or oval plaques that are typically itchy and may become crusted or pigmented. Other conditions can produce coin-shaped lesions, including tinea corporis (ringworm), granuloma annulare, and discoid lupus erythematosus. Because several diseases can present with similar circular lesions, clinical evaluation is important and may be supplemented by skin scrapings, cultures, or biopsy to establish an accurate diagnosis. The descriptor nummulær communicates lesion morphology rather than pinpointing a single disease.

Etymology: the word derives from Latin numulus for a small coin, adapted into Scandinavian medical terminology with the adjectival ending. In English-language dermatology, the cognate term is nummular, as in nummular eczema.