A78-27 No Wheeze, No Murmur - Just Clubbing

Introduction Nail clubbing is an exam finding linked to chronic hypoxemia. This condition is secondary to pulmonary, cardiac, gastrointestinal, endocrine, neoplastic, or autoimmune etiology. Clubbing due to pulmonary or cardiac disorders is most common. Clubbing is believed to be from megakaryocytes bypassing the lungs, reaching the fingertips, and releasing platelet-derived growth factor (PDGF), which promotes vascular and connective tissue changes. Clubbing can indicate poor prognosis but may improve with treatment of the underlying condition, though there is no direct therapy for it. Case A 41-year-old male with a 25-pack-year smoking history presented with two years of severe clubbing in all fingers and positive Schamroth signs. Cardiac and pulmonary examination were unremarkable. Discussion Echocardiogram revealed no congenital heart defects. Liver function tests were unremarkable, and the patient had no risk factors for cirrhosis. Patient had no symptoms concerning for inflammatory bowel disease. Thyroid stimulating hormone (TSH) was within normal limits. High-resolution CT (HRCT) showed centrilobular and paraseptal emphysema, biapical scarring, ground-glass opacities of the upper lobes, air-trapping, diffuse bronchial thickening, scattered pulmonary nodules up to 5 mm, and enlarged paratracheal lymph nodes. Imaging ruled out pulmonary fibrosis, interstitial lung disease, and lung cancer. CT abdomen pelvis revealed no extra-thoracic malignancy. Alpha-1 antitrypsin testing revealed MM genotype and normal enzyme level of 144 mg/dL. Pulmonary function testing (PFT) revealed mild obstructive lung defect, severe air trapping, and moderately reduced diffusion capacity. These results were most consistent with respiratory bronchiolitis-associated interstitial lung disease (RB-ILD). Typical HRCT features include those found in our patient. Symptoms are gradual and include dry cough, dyspnea, and wheezing; clubbing is rare. PFTs show obstructive changes with reduced diffusion capacity, as in our patient. Besides clinical and radiological findings, diagnosis requires pigmented “smoker’s macrophages” and a lack of lymphocytosis on bronchoalveolar lavage (BAL). Bronchoscopy was not ordered as imaging was suggestive of RB-ILD. There was no immunocompromise or exposures concerning for hypersensitivity pneumonitis. Biopsy is reserved for cases with atypical features or when noninvasive methods are not conclusive. The key intervention for RB-ILD is smoking cessation, which the patient has started. Smoking cessation may lead to improvement of inflammation but will not reverse emphysema. Corticosteroids may be tried if symptoms persist, but evidence of efficacy is limited. Prognosis is favorable, but follow-up HRCT has been ordered to track disease progression following smoking cessation and to evaluate the need for future BAL to obtain a definitive diagnosis.