The risks of certain comorbid conditions varied between the 2 groups of patients.
Patients with palmoplantar pustulosis (PPP) exhibited an overlapping comorbidity profile with patients with psoriasis vulgaris, but not with those who have pompholyx. Findings were reported recently in JAMA Dermatology.
Although the origin of PPP remains unclear, the researchers note that recent studies on its immunological and genetic pathogenesis suggest systemic involvement of the disease. PPP, which is characterized as a chronic relapsing pustular dermatosis affecting the palms and/or soles, has also been previously considered a variant of psoriasis, but several studies have found differences between the 2 conditions.
“Similar to psoriasis, PPP is occasionally accompanied by systemic conditions, including psoriatic arthritis (PsA) and autoimmune diseases,” said the study authors. “However, to our knowledge, the association of comorbidities with PPP has not been evaluated, and adjustment for possible confounders has not been performed.”
They conducted a nationwide population-based cross-sectional analysis to assess the risks of comorbidities among patients with PPP using data from the Korean National Health Insurance (NHI) database and the National Health Screening Program collected from January 1, 2010, to December 31, 2019.
The comorbidity profiles of Korean patients with PPP were then compared with patients with the 2 major differential diagnoses of PPP: psoriasis vulgaris and pompholyx. Participants were evaluated for 4 categories of comorbidities: inflammatory arthritis, cardiometabolic diseases, autoimmune diseases, and dermatological diseases.
A total of 37,399 patients with PPP (mean [SD] age, 48.98 [17.20] years; 51.7% female); 332,279 patients with psoriasis vulgaris (mean [SD] age, 47.29 [18.34] years; 58.7% male); and 365,415 patients with pompholyx (mean [SD] age, 40.92 [17.63] years; 57.4% female) were included in the analyses.
After adjusting for demographic covariates, patients with PPP were found to report significantly greater and lower risks of several comorbidities compared with those with psoriasis vulgaris:
Patients with PPP conversely showed significantly higher risks of the assessed comorbidities vs those with pompholyx after adjusting for demographic covariates: psoriasis vulgaris (aOR, 72.96; 95% CI, 68.19-78.05; P < .001), psoriatic arthritis (aOR, 8.06; 95% CI, 6.55-9.92; P < .001), ankylosing spondylitis (aOR, 1.91; 95% CI, 1.61-2.27; P < .001), type 1 diabetes (aOR, 1.33; 95% CI, 1.16-1.52; P < .001), type 2 diabetes (aOR, 1.33; 95% CI, 1.29-1.38; P < .001), Graves disease (aOR, 1.25; 95% CI, 1.11-1.42; P < .001), Crohn disease (aOR, 1.63; 95% CI, 1.11-2.40; P = .01), and vitiligo (aOR, 1.87; 95% CI, 1.65-2.12; P < .001).
Subgroup analyses also revealed differences in comorbidities according to sex and age. The researchers concluded that further studies are warranted to explore the pathogenetic mechanisms of these comorbidities and elucidate their associations with PPP.
Kim DH, Lee JY, Cho SI, Jo SJ. Risks of comorbidities in patients with palmoplantar pustulosis vs patients with psoriasis vulgaris or pompholyx in Korea. JAMA Dermatol. Published online April 27, 2022. doi:10.1001/jamadermatol.2022.1081