Childhood psoriasis was found to be significantly associated with environmental tobacco smoke exposure, whereas intrauterine smoking exposure was not associated with an increased risk in pediatric populations.
Despite one-third of cases of psoriasis beginning in childhood–with prevalence estimated to be 128 cases per 100,000 children–researchers note that there remains limited evidence on what risk factors may increase risk of pediatric onset.
“To date, infections, family history of psoriasis, stressors, and obesity have been related to childhood psoriasis. The effects of intrauterine or childhood tobacco smoke exposure and its relationship to childhood psoriasis have previously been reported in 2 studies,” they said.
Seeking to better understand the association between intrauterine, infantile, and childhood tobacco smoke exposure and incidence of pediatric psoriasis, researchers conducted a case-control study of patients younger than 18 years of age seen in the Turkish Ankara University Dermatology Department from June 2016 to March 2020 who had a diagnosis of psoriasis as a child (n = 130; mean [SD] age, 10.19 [3.92] years; 50.8% male).
Patients with a diagnosis of childhood psoriasis were compared with age- and sex-matched controls (n = 390), in which use of 1 or more cigarettes per day for at least 1 month during pregnancy was considered intrauterine smoke exposure for children and exposure to tobacco smoke in childhood was defined as the use of 1 or more cigarettes per day for at least 1 year by at least 1 permanent member of the household.
“From the pool of children managed in our clinic during the study period, 3 sex- and age-matched children with non-inflammatory skin diseases such as tinea, candida, molluscum contagiosum, or verruca vulgaris were included in the study as controls for each child with psoriasis,” explained researchers.
For the childhood psoriasis cohort, mean [SD] age of onset of psoriasis was not found to differ between males (7.61 [4.30]) and females (7.30 [3.62]; P = .876). Notably, the rate of having a family history of psoriasis was significantly higher in the intervention group compared with the control group (27.7% vs. 4.9%) (P < .001), as was reported incidence of overweight or obesity (P = .002), intrauterine tobacco smoke exposure (11.5% vs. 5.9%), and environmental tobacco smoke exposure at home (56.9% vs. 34.6%).
After conducting a multivariate conditional logistic regression analysis that adjusted for intrauterine smoking exposure, family history of psoriasis, and obesity, environmental tobacco exposure was found to be significantly associated with incidence of childhood psoriasis (OR, 2.23; 95% CI, 1.39-3.58).
Conversely, no significant relationship was found between intrauterine smoking exposure and incidence of childhood psoriasis (OR, 1.61; 95% CI, 0.75-3.43; P = .212).
Speaking on the study findings, researchers acknowledged several limitations, including the lack of comparison with the general Turkish population, the relatively low number of cases, and the lack of information regarding parental socioeconomic status.
“Further studies investigating the relationship between childhood psoriasis and degree of smoking exposure, and the timing of the exposure in large cohorts that have been diagnosed by expert dermatologists are needed to elucidate such a relationship,” they concluded.
Atak MF, Kundakci N, Farabi B. Link between childhood tobacco exposure and childhood psoriasis: A case-control study. Pediatr Dermatol. Published online December 17, 2021. doi:10.1111/pde.14896