Derm Dx: Scaling hyperkeratosis of one hand and both feet

A 58-year-old man requests evaluation for dermatitis that has been affecting his right hand for more than 1 year. He works in maintenance and frequently is in contact with detergents. Examination reveals hyperkeratosis and scaling of the right palm; the left palm is clear. Examination elsewhere is unremarkable, except for diffuse scaling and erythema of both feet, accompanied by nail ...