64-year-old man presented with a 3-week history of a diffuse, pruritic
rash that had started on his trunk and then spread to his entire cutaneous surface, including the palms of his hands and soles of his feet. Physical examination revealed widespread fine scaling and diffuse
erythema. Generalized
lymphadenopathy was noted. No
fever,
hair loss,
onycholysis, or nail shedding was detected. The patient had neither a personal history of skin disorders or, specifically,
atopic eczema or
psoriasis nor a family history of
eczema or
psoriasis. He also had no history of
malignancy and was taking no medications. The patient's complete blood cell count with differential was unremarkable. He was treated with moisturizers, topical
corticosteroids, and
antihistamines and was advised to avoid possible irritants. One week later, the patient returned because of a worsening of his
erythroderma. He also reported malaise and
chills. Three 4-mm biopsy specimens were obtained from representative areas (ie, back, arm, and abdomen), and a 2-week course of oral
corticosteroids was prescribed. The
erythroderma greatly improved but worsened shortly after the
steroid dose was tapered. The specimens showed psoriasiform
hyperplasia with features suggestive of
psoriasis vulgaris. The patient was treated with 25 mg of oral
acitretin once a day. His
erythroderma slowly resolved over 6 months, at which time the
acitretin dose was tapered. The patient reported no recurrence of the
erythroderma.