TABLE II.

Distinguishing features of FACU, ACU and FCAS

	FACU	ACU	FCAS
Inheritance pattern	Autosomal dominant	Usually sporadic	Autosomal dominant
Known genetic mutation	Unknown	Unknown	NLRP3
Onset in early childhood	++	-	++
Lifelong duration	+++	-	+++
Atmospheric cold elicitation	++	+	++
Immediate onset after cold exposure	+++	+++	-
Onset with ingestion of cold foods	++	++	-
Pruritis	+++	+++	+
Respiratory symptoms (bronchospasm)	+	++	-
CV collapse/Syncope	+	++	-
Fever or Chills	-	-	+++
Extremity Pain	-	-	+++
Cold Stimulation Timed Test	-	+++	-
Antihistamines Effective	++	+++	+

+++ Always

++ Most

+ Some

- None

NLRP3: NLR family, pyrin domain containing 3