Sjögren’s syndrome (SS) is a chronic autoimmune disorder primarily recognized for attacking the glands responsible for producing tears and saliva, leading to persistent dryness in the eyes and mouth (sicca symptoms). SS is a systemic condition that can affect numerous organs, including the skin. When the disease impacts the skin, it often manifests as a visible rash or other signs of inflammation, which can range from mild annoyance to indicators of widespread disease activity. Understanding the visual characteristics of a Sjögren’s-associated rash is an important part of managing the condition.
Appearance of the Sjögren’s Vasculitic Rash
The most distinct skin manifestation of Sjögren’s syndrome is a type of small-vessel inflammation known as leukocytoclastic vasculitis. This inflammation typically presents as palpable purpura, a rash of raised, non-blanching spots that are red or purple. They are called “palpable” because they feel like small bumps, distinguishing them from flat bruises or non-inflammatory redness.
Gravity and pressure influence the location of this rash, meaning the purpuric spots are most commonly found on the lower extremities, particularly the ankles and lower legs. The individual lesions are usually small, but they can merge to form larger patches. While often asymptomatic, some individuals report a mild burning sensation or itchiness.
As the inflammation subsides, the spots do not turn white when pressed because they represent the leakage of red blood cells outside the vessel walls. Once the active spots fade, they may leave behind residual brown or dark staining on the skin (post-inflammatory hyperpigmentation). In rare cases, severe vasculitis can progress to form small ulcers or areas of skin breakdown, particularly around the ankles.
Other Common Skin Manifestations
While the vasculitic rash indicates systemic inflammation, the most common skin issue is generalized dryness, known as xerosis. This pervasive dryness occurs because the autoimmune process targeting the lacrimal and salivary glands can also impair the function of the skin’s sweat and oil glands. The resulting skin is often rough, scaly, and prone to flaking, which can lead to intense itching (pruritus) across the body.
Another recognized, though less frequent, rash is annular erythema. This manifestation appears as distinct, ring-shaped, or circular patches of redness, often with a slightly raised edge and clearer skin in the center. These lesions typically favor sun-exposed areas such as the upper back, chest, face, and arms.
A heightened sensitivity to sunlight, termed photosensitivity, is frequently reported, especially by patients with annular erythema. Exposure to ultraviolet light can trigger or worsen these skin lesions, making sun protection a necessary part of daily management.
Underlying Immune Causes
The vasculitic rash is directly linked to the pathology of the autoimmune disease, representing an attack on the body’s own small blood vessels. This process is categorized as a small vessel vasculitis, where the immune system targets tiny vessels just beneath the skin’s surface. The rash is caused by the deposition of immune complexes—clusters of antibodies bound to antigens—that circulate in the bloodstream.
These immune complexes become lodged in the walls of the postcapillary venules, triggering a localized inflammatory response. This inflammation attracts immune cells, particularly neutrophils, which damage the vessel wall (leukocytoclasia). The resulting damage allows red blood cells to leak into the surrounding tissue, creating the characteristic non-blanching, purple-red spots of purpura.
The presence of vasculitis is often a sign of pervasive systemic disease activity in Sjögren’s and is linked with certain markers. Patients with this rash are more likely to have specific autoantibodies, such as anti-Ro/SSA. They may also present with conditions like cryoglobulinemia, which involves abnormal proteins in the blood that contribute to vessel blockage and inflammation.
Treatment and Management of Skin Symptoms
Management of Sjögren’s skin symptoms requires a dual approach, addressing both underlying systemic inflammation and resulting skin dryness. For the vasculitic rash, treatment focuses on reducing the autoimmune activity damaging the blood vessels. Mild cases may be managed conservatively, but persistent or severe vasculitis often necessitates systemic therapy, including antimalarial medications like hydroxychloroquine.
If vasculitis is severe, extensive, or affects internal organs, a physician may prescribe corticosteroids to rapidly decrease inflammation, or other immunosuppressive drugs. Treating the underlying systemic disease is essential, as the rash is a manifestation of the wider autoimmune process.
For managing chronic skin dryness (xerosis), the focus is on maintaining the skin barrier and preventing moisture loss. This involves frequent application of thick, non-irritating emollients, especially after bathing when the skin is damp. Avoiding harsh soaps and using a humidifier can also help mitigate persistent dryness. Due to recognized photosensitivity, sun-protective measures, including protective clothing and broad-spectrum sunscreen, are advised. Any new or worsening rash should be reported to a rheumatologist, as it may signal a flare-up requiring adjustment to the treatment plan.