Nummular eczema is characterized by an erythematous, edematous, vesicular, and crusted plaque. These commonly present on the upper and lower extremities. The lesions enlarge by forming satellite papulovesicles that coalesce with the original lesion. Pruritus is the dominant symptom.
Xerotic eczema (also called winter itch, eczema craquele, and asteatotic eczema) presents on the anterior shins, extensor arms, and flanks. The lesions are erythematous patches with fine, cracked fissures and adherent scaling. The edema and exudate present in nummular eczema is absent. Pruritus can be severe. This is a common finding in the winter and in the elderly.
Management and Disposition
Treatment consists of mid- to high-potency topical steroid. Prevention of secondary infection is important as patients frequently cannot resist scratching. Difficult to control, recurrent, and chronic cases should be referred to a dermatologist for advanced treatment. Xerotic eczema is treated with topical emollients (petrolatum), three to four applications per day. Topical steroids may be required for areas with inflammation.
Eczema. Nummular eczema of the wrist. Note the satellite lesions on the periphery. (Photo contributor: J. Matthew Hardin, MD.)
Nummular eczema should be considered with lesions unresponsive to antibiotic and antifungal medications.
Both entities are associated with significant pruritus and secondary infections, especially in the young and elderly.
Eczema. Nummular eczema on the extensor surface of the forearms and elbows. Thickened, scaly lesions resemble psoriatic plaques. A biopsy was performed to confirm the diagnosis. (Photo contributor: Richard P. Usatine, MD. Used with permission. From Usatine RP, Smith MA, Mayeaux EJ, Chumley HS. The Color Atlas of Family Medicine. 2nd ed. New York, NY: McGraw Hill; 2013: Fig. 148-6.)