Cigarette smoking, body mass index, and stressful life events as risk factors for psoriasis: results from an Italian case-control study.
We conducted a case-control study to analyse the association of psoriasis of recent onset with smoking habits, body mass index (BMI) and stressful life events. Cases (n=560; median age 38) were patients with a first diagnosis of psoriasis and a history of skin manifestations of no longer than two years after the reported disease onset. Patients with a new diagnosis of skin diseases other than psoriasis (n=690; median age 36) were selected as controls. The risk of psoriasis was higher in ex- and current smokers than in never-smokers, the relative risk estimates (OR) being 1.9 for ex-smokers and 1.7 for smokers. Smoking was strongly associated with pustular lesions (32 patients, OR=5.3 for smokers). The frequency of psoriasis varied significantly in relation to a family history of psoriasis in first degree relatives, BMI (OR=1.6 and 1.9 for over weighted, BMI 26-29, and obese, BMI >/= 30, respectively) and stressful life event score (compared to the lower index quartile, the OR being 2.2 for index values >/=115). Risk estimates, when taking into consideration the combined effect of these factors with smoking habits, were consistent with a multiplicative model of risk combination with no significant statistical interaction.
Centro Studi GISED, Ospedali Riuniti di Bergamo, Bergamo, Italy. luigi.naldi@gised.it
Luigi
L
Naldi
Liliane
L
Chatenoud
Dennis
D
Linder
Anna
A
Belloni Fortina
Andrea
A
Peserico
Anna Rosa
AR
Virgili
Pier Luigi
PL
Bruni
Vito
V
Ingordo
Giovanni
G
Lo Scocco
Carmen
C
Solaroli
Donatella
D
Schena
Annalisa
A
Barba
Anna
A
Di Landro
Enrico
E
Pezzarossa
Fabio
F
Arcangeli
Claudia
C
Gianni
Roberto
R
Betti
Paolo
P
Carli
Alessandro
A
Farris
Gian Franco
GF
Barabino
Carlo
C
La Vecchia
D000328:Adult; D015992:Body Mass Index; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D007558:Italy; D008297:Male; D008875:Middle Aged; D011565:Psoriasis / Q000209:etiology*; D012307:Risk Factors; D012907:Smoking / Q000009:adverse effects*; D013315:Stress, Psychological / Q000150:complications*