Granulomatosis with polyangiitis (GPA), previously known as Wegener's granulomatosis, is a rare systemic autoimmune disease that can affect various organs, including the skin. In dermatology, GPA manifests with a variety of skin lesions.
Granulomatosis with Polyangiitis (GPA) Explained
GPA is characterized by inflammation of blood vessels (vasculitis) and the formation of granulomas, which are clumps of immune cells. The exact cause is unknown, but it involves an abnormal immune response.
Dermatological Manifestations of GPA
While GPA is a systemic disease, it frequently involves the skin. Skin manifestations are seen in a significant proportion of patients. These can include:
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Palpable Purpura: Small, raised, reddish-purple spots caused by inflammation of small blood vessels.
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Ulcers: Open sores on the skin, often painful.
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Nodules: Firm lumps under the skin.
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Vesicles and Bullae: Small blisters (vesicles) or large blisters (bullae).
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Pyoderma Gangrenosum-like lesions: Ulcerative skin lesions.
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Subcutaneous nodules: Inflammatory nodules present beneath the skin.
Diagnosis
Diagnosing GPA involves a combination of clinical evaluation, laboratory tests, and sometimes a biopsy of affected tissue.
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Clinical Evaluation: Assessing symptoms and conducting a physical examination. Dermatological findings contribute to the overall assessment.
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Laboratory Tests:
- ANCA (Anti-Neutrophil Cytoplasmic Antibodies): A type of antibody commonly found in people with GPA.
- ESR and CRP: Markers of inflammation in the body.
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Biopsy: A skin biopsy can help confirm the diagnosis by showing vasculitis and granulomatous inflammation.
Treatment
The goal of treatment is to suppress the immune system and reduce inflammation. Common treatments include:
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Corticosteroids: Powerful anti-inflammatory drugs.
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Immunosuppressants: Medications that suppress the immune system, such as cyclophosphamide, methotrexate, or rituximab.
Importance of Dermatological Assessment
The dermatological manifestations of GPA are important for early diagnosis and management. A dermatologist can recognize the characteristic skin lesions and initiate appropriate investigations. Early diagnosis and treatment are crucial to prevent serious complications affecting the lungs, kidneys, and other organs.
