Lichen Planus Link to Dyslipidemia Found

BERLIN — Lichen planus, like psoriasis, appears to be intrinsically associated with an increased prevalence of dyslipidemia, according to a large Israeli case-control study.

“Of course, this is a pioneering study and I'd like to see it repeated in other databases. Nevertheless, we suggest that patients with lichen planus might be candidates for dyslipidemia screening,” Dr. Arnon D. Cohen said at the annual congress of the European Academy of Dermatology and Venereology.

He and his coinvestigators identified 1,477 patients aged 20–79 years with dermatologist-diagnosed lichen planus in the database of Clalit Health Services, Israel's largest health care organization. They also randomly selected 2,856 controls matched for age and gender, since lichen planus has a female preponderance.

The prevalence of dyslipidemia was 42.5% among the lichen planus patients, which was significantly greater than the 37.8% figure for controls, said Dr. Cohen.

After adjustment for potential confounders in a multivariate logistic regression analysis, lichen planus was independently associated with a 34% increased risk of dyslipidemia.

“That's similar to other studies done in psoriasis patients, which have shown increases of about 30% in rates of diabetes and dyslipidemia,” observed Dr. Cohen of Ben-Gurion University, Beer-Sheva, Israel.

Unlike what's been found in the psoriasis studies, however, the lichen planus patients did not have higher rates of hypertension, diabetes, obesity, or smoking than did the general population.

Since patients with lichen planus appear to be less likely than those with psoriasis to meet criteria for full-blown metabolic syndrome, it's also likely their cardiovascular event rate will be somewhat less as well, although this wasn't an end point in the lichen planus study, said Dr. Cohen at the meeting.

The case-control study also identified an intriguing, previously undescribed association between lichen planus and hypothyroidism.

The prevalence of hypothyroidism was 10% in the lichen planus group, compared with 5.7% in controls. The explanation for the link is as yet unclear, but Dr. Cohen indicated that he and his coworkers are eager to follow up on it.

Lichen planus is a common skin disease affecting up to 2% of the population. The finding that it's associated with an increased rate of dyslipidemia, as has previously been established to be the case in psoriasis, raises the question of whether the risk of hyperlipidemia is increased across the board in patients with the other chronic inflammatory papulosquamous skin diseases through some shared but unknown mechanism.

“I've analyzed preliminary data in patients with seborrheic dermatitis or pityriasis rubra pilaris, and I see the same association. But this definitely requires further research,” Dr. Cohen said.

“We're all focusing a lot of our energy and research on [the cardiovascular risk of] psoriasis. But we should focus on other diseases as well,” he added.

Dr. Cohen didn't report having any relevant conflicts of interest.