Watch for comorbid neurologic conditions in patients with pemphigus

Dementia, epilepsy, and Parkinson disease are twice as common in patients with pemphigus than in matched controls, Israeli investigators have discovered. The association is consistent with case reports that suggest coexistence of pemphigus with some specific neurologic conditions. They report their findings in JAMA Dermatology.

The association between pemphigus and neurologic disease was found in a retrospective population-based cross-sectional study using the database of the largest public healthcare organization in Israel. Between Jan. 1, 2004 and Dec. 31, 2014, a total of 1,985 patients with a new diagnosis of pemphigus and 9,874 controls matched for age, sex, and ethnicity were compared for the proportion with diagnoses of dementia, epilepsy, Parkinson disease, and multiple sclerosis (MS).

Of the 1,985 cases with pemphigus, 622 patients (31.3%) had dementia, 74 (3.7%) had epilepsy, 175 (8.8%) had Parkinson disease, and 2 (0.1%) had MS. Among the control cohort, 1,856 (18.8%) had dementia, 210 (2.1%) had epilepsy, 437 (4.4%) had Parkinson disease, and 6 (0.1%) had MS.

The odds of dementia (OR 1.97), epilepsy (OR 1.78), and Parkinson disease (OR 2.09) were all significantly higher among patients with pemphigus compared with controls, which remained significant after adjusting for comorbidity.

The patients with pemphigus also had higher rates of health care use.

“Physicians who care for patients with pemphigus should be aware of this association,” the authors wrote. “Further observational research is necessary to examine the temporality of this association and explore the existence of causality.”

An editorial by Dennis Linder, M.D., from the University of Oslo, Norway, and colleagues, appearing in the same issue of JAMA Dermatology, calls for additional exploration of local central nervous system alterations in autoimmune skin diseases. The association between pemphigus and neurologic comorbidities offers further support of immunologic cross-reactivity between the skin and brain. They noted that “at least 13 different antigens residing in the central or peripheral nervous system and in the skin or kidneys have now been shown to be targeted by IgG4, including the desmogleins targeted by pemphigus autoantibodies.”

REFERENCES

Khalaf Kridin, MD; Shira Zelber-Sagi, PhD; Doron Comaneshter, PhD; et al. “Association Between Pemphigus and Neurologic Diseases,” JAMA Dermatology. Published online February 16, 2018.DOI:10.1001/jamadermatol.2017.5799

Dennis Linder, MD; Stefano Piaserico, MD, PhD; Mauro Alaibac, MD, PhD. “Comorbidities in Autoimmune Skin Diseases,” JAMA Dermatology. Published online Feb. 16, 2018. DOI:10.1001/jamadermatol.2017.58