While some use the term 'polymorphic eruption of pregnancy' to cover these, this term is a synonym used in the UK for Pruritic urticarial papules and plaques of pregnancy, which is the commonest of these skin conditions.
These are sometimes referred to as a 'polymorphic eruption of pregnancy,' but this term is actually used in the UK to describe Pruritic urticarial papules and plaques of pregnancy, which is the most frequent of these skin conditions.