Table 1.

Clinical data of the patients.

Patient	Age at lower extremities involvement (y)	Age at upper extremities involvement (y)	Age at visit (y)	Other involved sites	Persistent pain	Seasonality	Triggering factors	SCNA9 mutation	Erythromelalgia crisis frequency	Disease control
1	7	7	18		yes		heat, humidity, emotional stress	c.2572C>T(e) (p.Leu858Phe) (pathogenetic); c.58C>T(e) (p.Leu20Phe) (VUS)	every day	not sufficient
2	8	12	43			yes, summer	sun exposure	c.3734A>G (p.Asn1245Ser) (benign)	once or twice weekly during summer months	good
3	10	43	43				heat, evening, alcohol	c.1999G<A (p.Asp678Asn) (VUS)	every day in the evening	good
4	15	21	21		yes		heat, humidity, physical activity	none	every day	good
5	4	4	42	knees, face		yes, summer	sun exposure	none	once or twice weekly in summer months	discrete
6	42	42	44	knees, ears, diffuse heat over the entire body	no, but persistent erythrosis		heat, humidity, emotional stress	none	once or twice weekly	discrete
7	24	24	37		no, but persistent erythrosis	yes, winter	heat	none	every day in winter months	poor
8	12	12	16	face, ears, knees			emotional stress, evening	none	every day	poor
9	39	37	39	occasionally burning sensation in other body sites		yes, summer	heat, evening	none	once or twice weekly in summer months	discrete
10	7	14	57			yes, summer	heat, sun exposure	none	once or twice weekly, every day in summer months	discrete
11	37	39	39		yes, with persistent edema		heat	c.4067G>A (p.Arg1356His) (benign)	every day	poor

VUS = variant of uncertain significance.