(224) Psoriatic Conditions After Lithium Exposure: French Pharmacovigilance Data

Publication Number: 1269

Background: Lithium is the cornerstone of bipolar disorders management. The first published report of psoriatic manifestation after lithium exposition dates from the 1970s. Lithium seems to cause predominantly exacerbation [1]. Psoriasis risk, de Novo or exacerbation, is now listed in its Summary Products of Characteristics. Surprisingly, we identify only one published study assessing the causal link. Brauchli et al, highlighted an increased risk for incident psoriasis with long-term lithium exposure (Odds Ratio 1.68, 95%CI 1.18–2.39) [2].

Objectives: We aimed to investigate pharmacovigilance data.

Methods: We described spontaneous reports of “psoriatic conditions” (High Level Term) recorded in the French national Pharmacovigilance Database (FPVD) between 1985 and 2021. A disproportionality analysis was performed using the case/non-case method. Cases were reports of “psoriatic conditions” (High Level Term). Non cases were all other cutaneous ADRs except psoriasis. Notifications involving SARS-CoV-2 vaccines were excluded. Reporting Odds Ratio (ROR) of psoriasis with lithium and its 95% confidence interval (95%CI) were calculated.

Results: During the study period, 218 323 spontaneous reports of cutaneous ADRs were registered in the FPVD. Thirty three reports involved “psoriatic conditions” with lithium. Mean age was 49.4 years (range 24 to 76 years); male/female ratio was 1.3. Fifty seven percent of reports were serious. Fifty one percent of reports were exacerbation cases. Psoriatic manifestations were: “plaque psoriasis” (n=29), “erythrodermic psoriasis” (n=2) and “psoriasiform dermatitis” (n=2). Mean time to onset was 39 weeks: 16 weeks for exacerbation cases and 70 weeks for induction cases. Lithium was discontinued in 60% of reports. Outcome was favorable after lithium discontinuation in 85% of reports. ROR of psoriasis with lithium was 3.48 (95%CI 2.45 – 4.93).

Conclusions: Psoriasis is reported 3 – 4 times more frequently with lithium than with other drugs, this disproportionality is statistically significant; thus constituting a pharmacovigilance signal. We believe that psoriasis risk with lithium is largely unknown to the medical community. Both exacerbation and induction cases are concerned. The study published by Brauchli et al focused on incident cases and excluded aggravation cases [2]; psoriasis risk was probably under-estimated. Time to onset appears shorter with exacerbation cases than with induction cases. Increasing skin surveillance during the 1st year of lithium exposure is needed.