What is this red patch on a woman's hand?

Dermclinic
A Photo Quiz to Hone Dermatologic Skills

Case 1:
A 69-year-old woman has had a red patch on the dorsum of one hand for 5 weeks. She states that the lesion began as a pimple and has grown larger; it is occasionally pruritic but not painful. Her history includes seasonal allergies; she does not keep any pets.

Do you recognize this lesion?

A. Tinea corporis.
B. Actinic keratosis.
C. Contact dermatitis.
D. Nummular eczema.
E. Impetigo.

(Answer on next page.)

Dermclinic – Answer

Case 1: Nummular eczema

Nummular eczema, D, typically occurs on the hands of atopic patients. A potassium hydroxide examination ruled out a dermatophyte infection, which was unlikely because of the absence of pets in the patient’s household. Actinic keratoses do not arise as acutely as this lesion, and they are asymptomatic. Impetigo usually spreads more widely, is self-limited, and disappears spontaneously. Contact dermatitis is less well-defined and usually clears in 2 to 3 weeks.

Mild soaps and hand moisturizers were recommended for the patient’s sensitive skin. The nummular eczema responded quickly to a corticosteroid cream.