Sclerema neonatorum is a rare and severe skin condition that is characterized by diffuse hardening of the subcutaneous tissue with minimal inflammation. It usually affects premature, ill newborns. Prognosis is poor. Sclerema neonatorum is a rare and severe skin condition that is characterized by diffuse hardening of the subcutaneous tissue with minimal inflammation. It usually affects premature, ill newborns. Prognosis is poor.