Skin Manifestations More Common Than Internal Organ Involvement in Sjögren Syndrome

Skin manifestations are significantly frequent among individuals with Sjögren syndrome (SS), with internal organ involvement being less common but still quite prevalent, according to a study published in the Journal of the European Academy of Dermatology and Venereology.¹

Furthermore, researchers noted that despite the frequency of internal organ involvement in SS, clinicians should know that there is no significant different in occurrence between primary versus secondary SS.

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Background and Methods

SS is a systemic autoimmune disease causing dry eyes and mouth, diagnosed through dryness signs and SS-A autoantibodies or lip biopsy. It can mimic the signs and symptoms of systemic lupus erythematosus (SLE), with commonly-reported dermatological manifestations including dryness and vasculitis.²

Researchers of the present study, André et al, noted that there have been prior studies, such as one published in the Journal of the American Academy of Dermatology and Venereology in 2018,³ that explored cases of cutaneous manifestations in SS from dermatological departments. However, they noted that the vast majority of SS research exists in the context of internal medicine—not dermatology.

In order to address this gap, they conducted a retrospective, single-center cohort study investigating the manifestations of SS among patients presenting to an outpatient autoimmune disease clinic between 2000 and 2016. This, combined with a long follow-up time, makes this the first known study of its kind.

Among patients, SS was diagnosed in individuals with positive Ro/SS-A antibodies and symptoms of eye or oral dryness, with the addition of a positive Schirmer's test. In some cases, patients also underwent salivary gland ultrasound procedures for diagnostic purposes.

Individuals who had previously undergone head or neck radiation or who had active hepatitis C, AIDS, sarcoidosis, amyloidosis, graft-versus-host disease, and IgG4-related disease, were excluded from participation.

Researchers conducted regular evaluations, including interviews, physical exams, lab tests, and imaging as needed. Secondary SS was diagnosed in patients with concomitant autoimmune diseases such as SLE, systemic sclerosis, and rheumatoid arthritis. Researchers identified the presence of internal organ involvement by detecting and assessing for neuropsychiatric symptoms, pericarditis, pulmonary fibrosis, pulmonary hypertension, glomerulonephritis, interstitial nephritis, autoimmune hepatitis, and primary biliary cirrhosis.

Findings

In total, 2416 serum samples were evaluated for Ro/SS-A antibodies, resulting in 185 patients meeting the diagnostic criteria for SS. Among these patients, 24.9% were diagnosed with primary SS, while the remaining 75.1% had secondary SS.

Patients in the study exhibited a range of clinical symptoms and laboratory findings. Common symptoms included myalgia/arthralgia and fatigue, which were more prevalent in those with secondary SS compared to primary SS. For instance, myalgia/arthralgia and fatigue were reported in 76.2% and 67.9% of patients with secondary SS, respectively, versus 41.3% and 47.6%, respectively, of patients with primary SS.

Skin manifestations were present in 74.9% of patients, with dermatitis/pruritus and specific lupus erythematosus-related skin issues being more common in those with secondary SS. Photosensitivity and Raynaud's phenomenon were notably more frequent in this patient population.

To a lesser extent, internal organ involvement was observed in 65.9% of patients, with neuropsychiatric manifestations, including polyneuropathy and depression, being among the most prevalent. Cardiopulmonary complications such as pericarditis and pulmonary fibrosis were also noted, though less common in nature.

Furthermore, the study also identified several risk factors for internal organ involvement in patients with SS, including the presence of myalgia/arthralgia, fatigue, and an age over 50 years. Researchers did not report significant differences in occurrence of internal organ involvement in patients with primary SS versus secondary SS.

Conclusions

"Severe and frequent Raynaud's phenomenon may be an early signal for a long term developing systemic sclerosis," according to study authors. "Accordingly, alopecia areata or Raynaud's phenomenon occurring in SS should prompt the clinician to carefully investigate for other autoimmune disease."

Potential limitations of the study, however, included its retrospective nature and its interpretation of primary versus secondary SS, for which there is currently no widely-accepted or established distinguishing criteria.

However, researchers noted the role of the study and its future implications due to its first-of-its-kind nature.

"Skin involvement in SS should not be underestimated, and its prevalence of 74.9% underlines the important role of dermatologists in SS patient care," concluded André et al.

References

1. André F, Bujak M, Frischhut N, et al. Sjögren syndrome from a dermatological perspective: a retrospective study of 185 SSA-Ro positive patients. J Eur Acad Dermatol Venereol. July 19, 2024. https://doi.org/10.1002/jvc2.498
2. Fox RI, Liu AY. Sjögren's syndrome in dermatology. Clin Dermatol. 2006;24(5):393-413. doi:10.1016/j.clindermatol.2006.07.005
3. Jhorar P, Torre K, Lu J. Cutaneous features and diagnosis of primary Sjögren syndrome: an update and review. J Am Acad Dermatol. 2018; 79(4): 736–745.