A Rare Presentation of Sarcoidosis: A Case of Acute Onset Bilateral Pulmonary Infiltrates and Skin Lesions.

abstractSarcoidosis is a multisystem granulomatous disease of uncertain etiology that most often involves the lungs and skin, though nearly any organ may be affected. Pulmonary disease typically manifests as bilateral hilar lymphadenopathy with diffuse interstitial infiltrates, whereas cutaneous involvement is reported in about 25%-35% of cases, presenting as erythema nodosum, plaques, nodules, or lupus pernio. Acute onset of extensive pulmonary infiltrates with cutaneous lesions other than erythema nodosum is uncommon and frequently misdirects clinicians toward infectious or malignant causes, particularly in tuberculosis-endemic regions. We describe a 35-year-old previously healthy male who presented with sudden dyspnea, persistent cough, and erythematous plaques and nodules on the extremities. Chest imaging revealed diffuse bilateral infiltrates with mediastinal lymphadenopathy, and laboratory findings showed elevated serum angiotensin-converting enzyme levels. Pulmonary function testing demonstrated a restrictive pattern with impaired diffusion capacity, while bronchoalveolar lavage revealed lymphocytosis with a CD4/CD8 ratio above 3.5. Skin biopsy confirmed noncaseating granulomas, establishing the diagnosis of sarcoidosis with pulmonary and cutaneous involvement. The patient was started on oral corticosteroid therapy with prednisone 60 mg daily, gradually tapered according to clinical response. Within 2 weeks, there was marked improvement in respiratory symptoms and regression of skin lesions, leaving only residual pigmentation. Follow-up lung function and imaging demonstrated near-complete resolution, and steroids were successfully discontinued after 6 months without recurrence. This case highlights the importance of recognizing sarcoidosis in acute pulmonary-cutaneous presentations, where timely diagnosis and corticosteroid therapy can lead to excellent outcomes.