Background: The occurrence of pruritic urticarial papules and plaques of pregnancy (PUPPP) was noted in four women with unusual family relationships.
Objective: The purpose of the study was to document the occurrence of PUPPP in these families and to make observations on their possible relevance.
Methods: Case reports of the four patients are detailed. Histologic and HLA studies are recorded.
Results: In both families, sisters were married to brothers. A common paternal influence is suggested.
Conclusion: We postulate that PUPPP may be a maternal response to a circulating paternal factor for which tolerance develops in subsequent pregnancies.