Biologics are efficacious for treating psoriasis vulgaris (PsV) and psoriatic arthritis (PsA), but sometimes must be terminated or changed for various reasons including ineffectiveness or adverse events. To find the optimal choice of biologics for treating psoriasis, we analyzed the real‐world data on drug survival and the reason for terminating or switching biologics. Medical records from patients with PsV or PsA, who visited the Department of Dermatology, Fukuoka University Hospital from 2010 to 2017, were analyzed. Two hundred and eleven patients received biologics, and 147 patients (69.7%) were treated with only one biologic, while 64 patients (30.3%) were switched to different products. Frequently used biologics in PsV were ustekinumab (UST), infliximab and adalimumab when calculated by patient‐year. Tumor necrosis factor inhibitor (TNFi) use decreased while UST and interleukin (IL)‐17 inhibitors increased in newly introduced patients. UST showed the highest survival rate as a first‐line drug, but the advantage was lost in the second reagent's group. The major reasons for terminating/switching biologics were as follows: primary ineffectiveness (26.4%), secondary loss of efficacy (36.5%), patient's preference, including referral to nearby hospital, or stopped visiting (22.6%), side‐effects (7.7%), comorbidities (3.4%) and economic burden (2.4%). In PsA patients, TNFi are more frequently employed than in PsV patients, although switching to UST or IL‐17 inhibitors showed an increasing trend. Biologic reagents were changed mostly because of primary or secondary loss of efficacy, which affected drug survival. Further research is needed to find the optimal choice of biologics with larger samples at multiple facilities.

Psoriasis is a chronic inflammatory disease that often involves the skin and joints. Psoriasis develops at any age and the distribution of age of onset of psoriasis is bimodal in Japan. Also, male predominance is distinct in Japanese psoriatic patients. To clarify the relationship between sex difference and habitual/environmental status, age and incidence of familial psoriasis, we analyzed data from the Fukuoka University Psoriasis Registry. A total of 1120 Japanese patients (751 men, 369 women) were analyzed. The male/female ratio was 2.03:1. Smoking and drinking habit, known as risk factors of psoriasis, were significantly more prevalent in men. Age-specific psoriasis-onset rate standardized by population showed bimodal distribution in both men and women; the younger peak was in their 30s for men and 10s in women; the second peak was in the 50s for both sexes. A familial history of psoriasis was seen in 6.3% of patients overall; however, female patients showed a significantly higher rate (8.7%) compared with men (5.1%, P = 0.024). When stratified by age of onset, the frequency of familial history was much higher among women with onset at less than 30 years (15.4%), compared with 30 years or more (5.3%, P = 0.0026). Our data suggest that genetic factors have a stronger influence in young women who experience fewer environmental factors such as smoking and drinking. This is the first study to show that there is a difference in the incidence of familial psoriasis depending on age of onset of psoriasis in Japan.

Chronic idiopathic erythroderma is an independent condition which is likely to occur in elderly men. Immunity is shifted to the Th2 type in CIE; however, the mechanism may differ from that of atopic dermatitis.

Psoriasis is a chronic inflammatory disease caused by both genetic and environmental factors. The occurrence of psoriasis in family members indicates a genetic predisposition, while obesity is also a major contributor to psoriasis. We examined whether patients with versus without familial psoriasis were obese at the onset of psoriasis. Clinical information, including age at onset, age at first visit and body mass index (BMI) at first visit, was extracted from the Fukuoka University Psoriasis Registry. To compare BMI, patients aged 10 years or older who visited the clinic within 3 years of onset were selected. Familial psoriasis was observed in 27 patients (15 male, 12 female) out of 428 individuals (264 male, 164 female) with psoriasis, accounting for 6.3% of cases. Age at onset was younger for both men and women with familial psoriasis (34 ± 17 and 40 ± 15 years, respectively) relative to those with non‐familial psoriasis (48 ± 19 and 53 ± 19 years, respectively). We examined age‐ and sex‐adjusted average values of BMI at initial presentation after onset of psoriasis, finding that patients with familial psoriasis had lower BMI (22.0 kg/m2 [95% confidence interval, 21.8–22.4]) than those with non‐familial psoriasis (23.2 [23.1–23.3], P < 0.001). Individuals with a family history of psoriasis should be considered to be at risk for developing the disease even if obesity is not present.

Psoriatic patients reportedly have a higher prevalence of inflammatory bowel disease (IBD); however, there have been few research studies of Japanese psoriatic patients. To elucidate the prevalence of IBD in Japanese psoriatic patients, a cross‐sectional study was performed. Information was collected regarding psoriatic patients with current or prior history of Crohn's disease (CD) or ulcerative colitis (UC) who were treated at Fukuoka University Hospital from 2010 to 2018. Among 681 psoriatic patients (449 men and 232 women), eight (1.2%, six men, two women) had UC and two (0.3%, one man, one woman) had CD. Diagnosis of IBD preceded psoriasis in five patients, while diagnosis of psoriasis preceded IBD in two; the remaining patients’ records did not have sufficient information. Seven of 10 UC‐positive patients had mild psoriasis, two had moderate psoriasis and one had severe psoriasis. When UC‐positive psoriatic patients were compared with IBD‐negative psoriatic patients, there were no differences in age at onset of psoriasis, age at first visit or complications (e.g. psoriatic arthritis, hypertension, hyperlipidemia, hyperuricemia and diabetes). However, UC‐positive patients had significantly higher body mass index (BMI) (26.7 vs 23.7; P = 0.021), compared with patients without IBD. The CD/UC ratio in this cohort was 0.25, while the prevalence of IBD was 1.2%; these values were both lower than those in previous reports involving Caucasian patients. Patients with psoriasis and UC may have higher BMI and milder skin symptoms than those with psoriasis alone. These observations must be further confirmed by controlled domestic studies with larger samples.