Strawberry Gingivitis as the Initial Manifestation of Granulomatosis with Polyangiitis in A Patient with Alpha-1 Antitrypsin Deficiency.

Background: Granulomatosis with polyangiitis (GPA) is a systemic necrotizing vasculitis, associated with anti-neutrophil cytoplasmic antibody (ANCA) that typically affects small- to medium-sized vessels in the upper and lower respiratory tracts and kidneys. While oral involvement is uncommon, the pathognomonic finding of "strawberry gingivitis" can be an initial manifestation in rare cases. The gingivitis presents as a friable, hyperplastic, erythematous gingival lesion. Recognizing this manifestation is critical, as it may precede systemic involvement and facilitate early diagnosis and intervention. Case presentation: We report a case of a 56-year-old male with a history of chronic epistaxis, alpha-1 antitrypsin deficiency, and recent new onset joint pain who presented with a two-month history of painful gums refractory to antibiotic treatment. Histopathology of the lesion as well as - a positive proteinase 3 titre - and a cytoplasmic ANCA staining pattern confirmed GPA and C-reactive protein was elevated. With this diagnosis, he was treated with prednisone and methotrexate and later switched to azathioprine due to potential toxicity, leading to symptom resolution and normalization of inflammatory markers. At 1-year follow-up, he remained clinically stable on azathioprine 100 mg daily. Conclusion: Our case highlights the importance of recognizing strawberry gingivitis as a rare but pathognomonic early manifestation of GPA. It underscores the need for prompt biopsy and serologic testing for accurate diagnosis and suggests that alpha-1 antitrypsin deficiency should raise clinical suspicion for GPA. Early initiation of immunosuppressive therapy is crucial to prevent progression to severe systemic disease. LEARNING POINTS: Strawberry gingivitis, albeit uncommon, is a pathognomonic oral manifestation of granulomatosis with polyangiitis (GPA) and may be the first clinical indication in the absence of systemic signs.Prompt recognition and biopsy of atypical oral lesions can aid in the early detection of GPA and avert potentially deadly consequences.Alpha-1 antitrypsin deficiency, which is frequently ignored, may contribute to GPA development and should be evaluated during the diagnostic workup, especially in patients with a family history or pulmonary susceptibility.