Symmetrical bilateral Velcro crackles

Specialty: Respiratory.

• symmetrical fibrosis rattles
• symmetric bibasal dry crackles

Why it occurs

• Idiopathic pulmonary fibrosis (IPF) (classic auscultatory pattern characterized by dry, fine rales with a high timbre, present at both lung bases symmetrically that persist throughout the respiratory cycles and are not modified by cough, indicative of histological honeycombing and distortion of lung architecture)
• Diffuse interstitial pneumopathy associated with progressive systemic sclerosis (basal-posterior scleroderma)
• Chronic bilateral silica or asbestos inhalation pneumoconiosis
• Pulmonary toxicity reaction induced by drugs of chronic systemic use (for example, Nitrofurantoin, Amiodarone or Methotrexate)
• Stage IV sarcoidosis with symmetrical bibasal fibrosis.

Initial workup

High-resolution chest computed tomography (CT) (HRCT) without contrast as a priority (NIU or NIIE pattern search); Forced spirometry with whole body plethysmography and diffusing capacity for carbon monoxide (DLCO); 6-minute walk test with continuous oximetry; Analysis with autoimmunity profile (ANA, anti-Scl70, anti-JO1, rheumatoid factor).

Standard management

• Nintedanib — 150 mg orally every 12 hours in IPF or in fibrosing interstitial lung diseases with a progressive phenotype
• Pirfenidone — 801 mg orally every 8 hours, with an initial progressive scale to mitigate photosensitivity and gastrointestinal effects
• Prednisone (20-40 mg orally per day in case of confirmed active connective tissue disease with initial alveolar inflammatory component).