Late-onset psoriasis demonstrates different genetic factors than early-onset

National report - Although the clinical symptoms and overall management of early- and late-onset psoriasis are similar, late-onset psoriasis can offer very different challenges ranging from disease severity to the heightened caution required when choosing systemic therapies.

“Psoriasis can begin at an advanced age, and in my experience, it is quite common for it to start in someone age 60 years and older, which presents a different spectrum of disease management issues,” says Mark Lebwohl, M.D., Sol and Clara Kest professor and chairman, department of dermatology, Mount Sinai School of Medicine, New York.

Disease variants

A variety of medications (such as prednisone) are more commonly used in older patients. Because withdrawal from systemic steroids is the most common cause of pustular and erythrodermic psoriasis, these disease variants are far more common in elderly patients compared with younger patients, Dr. Lebwohl says. And while guttate psoriasis may be more common in a younger patient population, plaque psoriasis is common in both younger and older patient groups.

Both early- and late-onset psoriasis patients can have mild, moderate or severe symptoms, says Johann E. Gudjonsson, M.D., Ph.D., director of dermatology inpatient and consultation service and assistant professor, department of dermatology, University of Michigan, Ann Arbor, Mich. Although elderly patients are generally thought to have a milder disease, many have an active and severe disease course.

“Unfortunately, there is very little data comparing early- and late-onset psoriasis. In my experience however, a significant portion of the elderly-onset psoriasis patients will have moderate-to-severe disease that can often be quite difficult to control,” Dr. Gudjonsson says.

Genetic factors

Early-onset psoriasis is thought to have a different set of genetic factors than late-onset disease. According to Dr. Gudjonsson, the two psoriasis groups might differ both biologically and immunologically. There are over 30 known genetic factors associated with psoriasis, and not every patient will carry the same genetic risk factors.

One of the strongest genetic factors is the class I human leukocyte antigen HLA-Cw6, which is found to be much more common in patients with early-onset psoriasis compared with patients who have late-onset disease, Dr. Gudjonsson says.

Coexisting conditions

“Psoriasis is probably not a single disease entity and often coexists with other conditions such as obesity, type 2 diabetes, hypertriglyceridemia and cardiovascular disease,” Dr. Gudjonsson says. “In a portion of patients with late-onset psoriasis, the symptoms are severe, which often require the implementation of systemic therapies. However, the advanced age of the patient as well as the existence of these comorbidities and the drugs they take for these conditions often make therapeutic decisions challenging.”

Elderly psoriasis patients often have comorbidities, and it is not uncommon that some of the drugs they take exacerbate their symptoms of psoriasis, Dr. Lebwohl explains. TNF blockers taken by patients for their rheumatoid arthritis can cause a TNF-induced psoriasis, and similarly, psoriasis can be exacerbated in patients who are treated with interferon for conditions such as hepatitis C.

Though both angiotensin receptor blockers (ARBs) and angiotensin converting enzyme (ACE) inhibitors are known to exacerbate psoriasis, ARBs are less likely to do so, Dr. Lebwohl says, adding that he tries to switch his elderly psoriasis patients from ACEs to ARBs when possible.

Treatment considerations

Methotrexate and cyclosporine are two systemic agents often used in patients with more severe psoriasis. In older psoriasis patients, however, Dr. Lebwohl says caution is warranted when using these medications, as this patient population can be less resilient to the side effects of these drugs.

Methotrexate can cause bone marrow suppression resulting in low blood counts, white blood cells and platelets, Dr. Gudjonsson says. Because elderly patients are generally more prone to infection, this and other systemic agents must be used judiciously. “We do use these systemic medications when necessary. However, we first always try to treat more aggressively topically before resorting to systemic therapies,” Dr. Gudjonsson says.

Established guidelines regarding appropriate treatment and management in the late-onset group are lacking, he says.

“Psoriasis in the elderly is managed to a large degree similarly to the way it is managed in younger patients, but we are more careful about medications like methotrexate, and we pay more attention to the medications they are being treated with for their other standing comorbidities,” Dr. Lebwohl says. DT

Disclosures: Drs. Lebwohl and Gudjonsson report no relevant financial interests.