Age at onset influences psoriatic arthritis disease factors

A new study suggests age at onset strongly influences psoriatic arthritis disease phenotype, making this a viable stratification option in epidemiological and genetic psoriatic arthritis studies.

Researchers in Spain conducted a retrospective cohort study on 205 consecutive psoriatic arthritis patients, and published their results in the Joint Bone Spine journal Dec. 29, 2015.

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They found age of onset influenced several disease domains. Early onset psoriasis, for example, tended to have more extensive skin involvement, axial pattern as disease onset and mixed pattern during evolution, family history of both psoriasis and psoriatic arthritis and higher prevalence of HLA-C*06 and HLA-B*27, according to the study’s abstract. Early onset arthritis had more family history of psoriatic arthritis and HLA-B*27 positivity.

“…most of the genetic basis of psoriatic disease within it resides in the HLA region. For decades, HLA-C*06 has been accepted as the main descriptor of the two main phenotypes of skin psoriasis. There is now compelling evidence to suggest that HLA-C*06 is only a genetic biomarker for skin involvement and not for joint involvement in psoriatic disease,” according to another recent study's abstract. “The role of HLA-B*27 in the genetic [etiology] of [psoriatic arthritis] has been recognized since the 1970s.”

In the study in Joint Bone Spine, patients with late onset arthritis, on the other hand, were more likely to have diabetes, hypertension, dyslipidemia and obesity. Late onset psoriasis subjects tended to have more obesity, diabetes, hypertension and ischemic heart disease during follow-up. In multivariate analysis, late-onset psoriasis predicted diabetes development, while late-onset arthritis was an independent risk factor for hypertension.

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“As the authors state, early onset gives more extensive disease. This is really important. But the more worrisome findings are that [late-onset arthritis] has more metabolic complications. Dermatologists must be apprised of these findings and must disseminate these to their patients because as we know the dermatologist is usually the one that finds the [psoriatic arthritis],” says Helen M. Torok, M.D., medical director of Trillium Creek Dermatology, in Medina, Ohio.

“Personally, I treated a patient last week who had a swollen index finger for two months. She was treated with three different antibiotics. She sought out a dermatologist to see if she could get rid of her ‘infected finger.’ She had classical dactylitis, which is the hallmark of [psoriatic arthritis],” she says.

Dermatologists can make a big difference in the lives of psoriasis patients with and without psoriatic arthritis, Dr. Torok tells Dermatology Times.

“Any and all information that addresses psoriasis and / or psoriatic arthritis needs to be presented to dermatologists,” Dr. Torok says. “Psoriasis and [psoriatic arthritis] has such a profound impact on not only their quality of life but also on the health of their life.”

References:

1.     Alonso S, Tejón P, Sarasqueta C, Coto P, Alperi M, Queiro R. Age at disease onset may help to further characterize the disease phenotype in psoriatic arthritis. Joint Bone Spine. 2015 Dec 29. 

2.     Queiro R, Morante I, Cabezas I, Acasuso B. HLA-B27 and psoriatic disease: a modern view of an old relationship.Rheumatology (Oxford). 2015 Aug 19.