Pemphigus herpetiformis (PH) is characterized by grouped vesicular or papular pruritic lesions with histologic and immunopathologic features of pemphigus. PH can manifest at any age, and paraneoplastic cases have been reported. We describe a healthy boy born with acral crateriform erosions of the hands and feet whose 35-year-old mother had similar lesions. Biopsies from both patients were most consistent with PH. The mother was diagnosed with high-grade B-cell non-Hodgkin lymphoma and began chemotherapy with dexamethasone, and her lesions quickly improved. The infant had no additional lesions after 3 weeks of age and his acral erosions healed. To our knowledge, this is the first report of a diagnosis of PH in an infant and the first case of transplacental transmission of PH. This is also the first report of paraneoplastic PH in lymphoma. This case adds to the growing differential diagnosis of skin disease in postpartum women and their neonates.