Acquired C1 esterase inhibitor deficiency

Acquired C1 esterase inhibitor deficiency presents with symptoms indistinguishable from hereditary angioedema, but generally with onset after the fourth decade of life.:153peripheral: Purine nucleoside phosphorylase deficiency Acquired C1 esterase inhibitor deficiency presents with symptoms indistinguishable from hereditary angioedema, but generally with onset after the fourth decade of life.:153 C4 levels are low and C3 levels are normal.