Pneumoconiosis

Pneumoconiosis is a restrictive interstitial lung disease: it means that it’s associated with damage to the lung parenchyma and since lung parenchyma is damaged you would expect that lung fibrosis occurs , all lung volumes are going to decrease , diffusion capacity through alveoli is going to decrease hypoxia and hypoxemia and pulmonary HTN would occur,

To the fanatics in equations and graphs always remember that A-a ratio would increase, though it always confuses me that though alveoli are fibrosed so they are going to be ventilated??! Unless ventilation is meant to describe the patency of airways so by this my confusion would resolve :)) so if you may clarify this information to me please add your comment

Pneumoconiosis is associated with foreign body inhalation which would trigger inflammation and macrophages that would engulf the FB and induce an inflammatory response , I believe that the fibrosis occurs secondary to the inflammatory response and liberated proteolytic enzymes liberated secondary to this inflammatory reaction , and therefore it would take years for ILD and lung fibrosis to develop ,

Most specific diagnosis is established through lung biopsy,

Famous types of pneumoconiosis include:

1 Asbestosis:

Asbestosis exposure occurs in Shipyards, foundries (always forget) , pipes and insulators(damn it’s so hard to remember !)

Associated with high penetration capacities and high risk for development of lung cancers and hers they are going to trick you in Exam!

How?!

Asbestosis is specifically associated with pleural effusions and mesotheliomas due to its penetrating capabilities note to take that may reach to sub pleural parts but they don’t reach to the alveoli, what this is gonna benefit us to know this information ? Is that a pleural biopsy would not be helpful and that still lung biopsy is needed,

Still this is not the tricky part the tricky part is that the most common associated cancer with Asbestosis is bronchogenic carcinomas NOT MESOTHELIOMAS ! Whether it‘s an adenocarcinoma or SCC (peripheral or central, cavitations, hypercalcemia presence)

2 Silicosis: Sand blasting, pottery and glass productions and co associated with coal mines!

Silicosis results in large sized interstitial densities that may coalesce together to form characteristic eggshell calcifications, also they inhibit phagocytic functions of macrophages and its ability to engulf bacteria so surprise- surprise! Always expect reactivation of T.B.! Do tuberculin test if positive start INH therapy for 9 months.

N.B. I haven’t seen a patient with silicosis but I always get confused how to differentiate between eggshell calcifications and pulmonary rheumatoid nodules in Caplan’s syndrome.

3- Coal worker’s pneumonia….