Although psoriasis has a familial incidence of about 40%1,2 and there are abundant data indicating that genetic factors are operative in the cause of psoriasis,3,4 the mode of inheritance remains controversial. Attempts to ascertain the mode of inheritance have focused on studies of
See also editorial p 657.听
twins affected with psoriasis.5 However, such studies are often biased owing to the tendency to report only concordant twin pairs.6 In this article, we report an unusual pedigree of a family with psoriasis that includes dizygotic twins and trizygotic triplets.
Report of a Case听
A 19-year-old man was referred to the University of Chicago Hospitals for treatment of a recent exacerbation of his psoriasis. The patient's condition was first diagnosed as psoriasis at the age of 6 years, and he had subsequently experienced several severe exacerbations, one requiring hospitalization. Clinical examination demonstrated well-circumscribed, erythematous plaques covered by a